Cells specialized to detect chemical substances and relay that information centrally in the nervous system. Chemoreceptor cells may monitor external stimuli, as in TASTE and OLFACTION, or internal stimuli, such as the concentrations of OXYGEN and CARBON DIOXIDE in the blood.
A small cluster of chemoreceptive and supporting cells located near the bifurcation of the internal carotid artery. The carotid body, which is richly supplied with fenestrated capillaries, senses the pH, carbon dioxide, and oxygen concentrations in the blood and plays a crucial role in their homeostatic control.
Small clusters of chemoreceptive and supporting cells located near the ARCH OF THE AORTA; the PULMONARY ARTERIES; and the CORONARY ARTERIES. The aortic bodies sense PH; CARBON DIOXIDE; and OXYGEN concentrations in the BLOOD and participate in the control of RESPIRATION. The aortic bodies should not be confused with the PARA-AORTIC BODIES in the abdomen (which are sometimes also called aortic bodies).
A respiratory stimulant that enhances respiration by acting as an agonist of peripheral chemoreceptors located on the carotid bodies. The drug increases arterial oxygen tension while decreasing arterial carbon dioxide tension in patients with chronic obstructive pulmonary disease. It may also prove useful in the treatment of nocturnal oxygen desaturation without impairing the quality of sleep.
Relatively complete absence of oxygen in one or more tissues.
A general class of ortho-dihydroxyphenylalkylamines derived from tyrosine.
An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.
A fast inactivating subtype of shaker potassium channels that contains two inactivation domains at its N terminus.
A shaker subfamily of potassium channels that participate in transient outward potassium currents by activating at subthreshold MEMBRANE POTENTIALS, inactivating rapidly, and recovering from inactivation quickly.
Potassium channels that contain two pores in tandem. They are responsible for baseline or leak currents and may be the most numerous of all K channels.
The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.
An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
A highly poisonous compound that is an inhibitor of many metabolic processes and is used as a test reagent for the function of chemoreceptors. It is also used in many industrial processes.
A potassium-selective ion channel blocker. (From J Gen Phys 1994;104(1):173-90)
Organic compounds that contain two nitro groups attached to a phenol.
A photographic fixative used also in the manufacture of resins. According to the Fourth Annual Report on Carcinogens (NTP 85-002, 1985), this substance may reasonably be anticipated to be a carcinogen (Merck Index, 9th ed). Many of its derivatives are ANTITHYROID AGENTS and/or FREE RADICAL SCAVENGERS.
Cell membrane glycoproteins that are selectively permeable to potassium ions. At least eight major groups of K channels exist and they are made up of dozens of different subunits.
A major class of calcium activated potassium channels whose members are voltage-dependent. MaxiK channels are activated by either membrane depolarization or an increase in intracellular Ca(2+). They are key regulators of calcium and electrical signaling in a variety of tissues.
The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).
The act of breathing with the LUNGS, consisting of INHALATION, or the taking into the lungs of the ambient air, and of EXHALATION, or the expelling of the modified air which contains more CARBON DIOXIDE than the air taken in (Blakiston's Gould Medical Dictionary, 4th ed.). This does not include tissue respiration (= OXYGEN CONSUMPTION) or cell respiration (= CELL RESPIRATION).
The dilated portion of the common carotid artery at its bifurcation into external and internal carotids. It contains baroreceptors which, when stimulated, cause slowing of the heart, vasodilatation, and a fall in blood pressure.
A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.
A condition of decreased oxygen content at the cellular level.
Several clusters of chemoreceptive and supporting cells associated with blood vessels and nerves (especially the glossopharyngeal and vagus). The nonchromaffin paraganglia sense pH, carbon dioxide, and oxygen concentrations in the blood and participate in respiratory, and perhaps circulatory, control. They include the CAROTID BODY; AORTIC BODIES; the GLOMUS JUGULARE; and the GLOMUS TYMPANICUM.
Potassium channel whose permeability to ions is extremely sensitive to the transmembrane potential difference. The opening of these channels is induced by the membrane depolarization of the ACTION POTENTIAL.
A potent vasodilator agent with calcium antagonistic action. It is a useful anti-anginal agent that also lowers blood pressure.
The movement of cells or organisms toward or away from a substance in response to its concentration gradient.
The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.
A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
An electrophysiologic technique for studying cells, cell membranes, and occasionally isolated organelles. All patch-clamp methods rely on a very high-resistance seal between a micropipette and a membrane; the seal is usually attained by gentle suction. The four most common variants include on-cell patch, inside-out patch, outside-out patch, and whole-cell clamp. Patch-clamp methods are commonly used to voltage clamp, that is control the voltage across the membrane and measure current flow, but current-clamp methods, in which the current is controlled and the voltage is measured, are also used.
A clinical manifestation of abnormal increase in the amount of carbon dioxide in arterial blood.
A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.
Receptors in the vascular system, particularly the aorta and carotid sinus, which are sensitive to stretch of the vessel walls.
An involuntary movement or exercise of function in a part, excited in response to a stimulus applied to the periphery and transmitted to the brain or spinal cord.
The 9th cranial nerve. The glossopharyngeal nerve is a mixed motor and sensory nerve; it conveys somatic and autonomic efferents as well as general, special, and visceral afferents. Among the connections are motor fibers to the stylopharyngeus muscle, parasympathetic fibers to the parotid glands, general and taste afferents from the posterior third of the tongue, the nasopharynx, and the palate, and afferents from baroreceptors and CHEMORECEPTOR CELLS of the carotid sinus.
The interruption or removal of any part of the vagus (10th cranial) nerve. Vagotomy may be performed for research or for therapeutic purposes.
The resection or removal of the nerve to an organ or part. (Dorland, 28th ed)
The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)
Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.
The motor nerve of the diaphragm. The phrenic nerve fibers originate in the cervical spinal column (mostly C4) and travel through the cervical plexus to the diaphragm.
The lower portion of the BRAIN STEM. It is inferior to the PONS and anterior to the CEREBELLUM. Medulla oblongata serves as a relay station between the brain and the spinal cord, and contains centers for regulating respiratory, vasomotor, cardiac, and reflex activities.
Histochemical localization of immunoreactive substances using labeled antibodies as reagents.
Part of the brain located in the MEDULLA OBLONGATA and PONS. It receives neural, chemical and hormonal signals, and controls the rate and depth of respiratory movements of the DIAPHRAGM and other respiratory muscles.
A pathological condition caused by lack of oxygen, manifested in impending or actual cessation of life.
A transient absence of spontaneous respiration.
Neurons which send impulses peripherally to activate muscles or secretory cells.
The physical or mechanical action of the LUNGS; DIAPHRAGM; RIBS; and CHEST WALL during respiration. It includes airflow, lung volume, neural and reflex controls, mechanoreceptors, breathing patterns, etc.
The total volume of gas inspired or expired per unit of time, usually measured in liters per minute.
Inorganic salts of HYDROGEN CYANIDE containing the -CN radical. The concept also includes isocyanides. It is distinguished from NITRILES, which denotes organic compounds containing the -CN radical.
Proteins found in any species of bacterium.
GRAY MATTER located in the dorsomedial part of the MEDULLA OBLONGATA associated with the solitary tract. The solitary nucleus receives inputs from most organ systems including the terminations of the facial, glossopharyngeal, and vagus nerves. It is a major coordinator of AUTONOMIC NERVOUS SYSTEM regulation of cardiovascular, respiratory, gustatory, gastrointestinal, and chemoreceptive aspects of HOMEOSTASIS. The solitary nucleus is also notable for the large number of NEUROTRANSMITTERS which are found therein.
The 10th cranial nerve. The vagus is a mixed nerve which contains somatic afferents (from skin in back of the ear and the external auditory meatus), visceral afferents (from the pharynx, larynx, thorax, and abdomen), parasympathetic efferents (to the thorax and abdomen), and efferents to striated muscle (of the larynx and pharynx).
Cell surface proteins that bind amino acids and trigger changes which influence the behavior of cells. Glutamate receptors are the most common receptors for fast excitatory synaptic transmission in the vertebrate central nervous system, and GAMMA-AMINOBUTYRIC ACID and glycine receptors are the most common receptors for fast inhibition.
An abnormal increase in the amount of oxygen in the tissues and organs.

Post-ingestive feedbacks and associative learning regulate the intake of unsuitable sterols in a generalist grasshopper. (1/1554)

Behavioural studies of the grasshopper Schistocerca americana were undertaken to identify the mechanisms that regulate the intake of dietary sterols. In the first experiment, grasshoppers were allowed to feed on spinach, a plant containing only unsuitable sterols; immediately after this first meal, a suitable or unsuitable sterol was injected into the haemolymph. Grasshoppers injected with unsuitable sterols had second meals on spinach that were significantly shorter than those of grasshoppers injected with suitable sterols, indicating that unsuitable dietary sterols are detected post-ingestively. In the second experiment, grasshoppers were fed food containing only unsuitable sterols and were then presented with glass-fibre discs containing different concentrations of a suitable sterol or sucrose only (the control). The results suggest that grasshoppers do not use a direct feedback operating on mouthpart chemoreceptors to regulate their intake of suitable sterols. In the third experiment, grasshoppers were presented with artificial diets containing different sterols and flavours, and feeding was observed over a sequence of meals. The results from both the first and last experiments suggest a role for associative learning in regulating the intake of unsuitable sterols.  (+info)

Quantitative structure-activity relationships for nasal pungency thresholds of volatile organic compounds. (2/1554)

A model was developed for describing the triggering of nasal pungency in humans, based on the partition of volatile organic compounds (VOCs) between the air phase and the biophase. Two partition parameters are used in the model: the water-air partition coefficient and the octanol-water partition coefficient. The model was validated using data from the literature, principally on alcohols, acetates and ketones. The model suggests that all test compounds, regardless of their chemical functional groups, bind to a common receptor site within the hydrophobic interior of the bilayer membrane of the trigeminal nerve endings. There is probably only a slight, non-specific interaction between the VOC molecule and the receptor molecule, whereas this type of non-specific interaction for the detection of odor is much stronger. In practical terms, the suggestion that all VOCs share a common irritation receptor site implies that nasal-pungency thresholds of individual VOCs may be additive. Quantitative structure-activity relationships (QSARs) for nasal-pungency thresholds were also developed from the model, which can be used to predict nasal-pungency thresholds of common VOCs. Although the present model does not offer additional precision over that of M.H. Abraham et al., 1996, Fundam. Appl. Toxicol. 31, 71-76, it requires fewer descriptors and offers a physiological basis to the QSAR. Another advantage of the present model is that it also provides a basis for comparison between the olfactory process and nasal pungency.  (+info)

Chemotactic responses of Escherichia coli to small jumps of photoreleased L-aspartate. (3/1554)

Computer-assisted motion analysis coupled to flash photolysis of caged chemoeffectors provides a means for time-resolved analysis of bacterial chemotaxis. Escherichia coli taxis toward the amino acid attractant L-aspartate is mediated by the Tar receptor. The physiology of this response, as well as Tar structure and biochemistry, has been studied extensively. The beta-2, 6-dinitrobenzyl ester of L-aspartic acid and the 1-(2-nitrophenyl)ethyl ether of 8-hydroxypyrene-1,3,6-tris-sulfonic acid were synthesized. These compounds liberated L-aspartate and the fluorophore 8-hydroxypyrene 1,3,6-tris-sulfonic acid (pyranine) upon irradiation with near-UV light. Photorelease of the fluorophore was used to define the amplitude and temporal stability of the aspartate jumps employed in chemotaxis experiments. The dependence of chemotactic adaptation times on aspartate concentration, determined in mixing experiments, was best fit by two Tar aspartate-binding sites. Signal processing (excitation) times, amplitudes, and adaptive recovery of responses elicited by aspartate jumps producing less than 20% change in receptor occupancy were characterized in photorelease assays. Aspartate concentration jumps in the nanomolar range elicited measurable responses. The response threshold and sensitivity of swimming bacteria matched those of bacteria tethered to glass by a single flagellum. Stimuli of similar magnitude, delivered either by rapid mixing or photorelease, evoked responses of similar strength, as assessed by recovery time measurements. These times remained proportional to change in receptor occupancy close to threshold, irrespective of prior occupancy. Motor excitation responses decayed exponentially with time. Rates of excitation responses near threshold ranged from 2 to 7 s-1. These values are consistent with control of excitation signaling by decay of phosphorylated pools of the response regulator protein, CheY. Excitation response rates increased slightly with stimulus size up to values limited by the instrumentation; the most rapid was measured to be 16 +/- 3 (SE) s-1. This increase may reflect simultaneous activation of CheY dephosphorylation, together with inhibition of its phosphorylation.  (+info)

Trigeminal and carotid body inputs controlling vascular resistance in muscle during post-contraction hyperaemia in cats. (4/1554)

1. In anaesthetized cats, the effects of stimulation of the receptors in the nasal mucosa and carotid body chemoreceptors on vascular resistance in hindlimb skeletal muscle were studied to see whether the responses were the same in active as in resting muscle. The measurements of vascular resistance were taken, first, in resting muscle, and second, in the immediate post-contraction hyperaemic phase that followed a 30 s period of isometric contractions. 2. Stimulation of the receptors in the nasal mucosa caused reflex apnoea and vasoconstriction in muscle. The latter response was attenuated when the test was repeated during post-contraction hyperaemia. 3. Stimulations of the carotid bodies were made during a period of apnoea evoked reflexly by electrical stimulation of both superior laryngeal nerves. This apnoea prevented any effects of changes in respiration on the carotid body reflex vascular responses. Stimulation of the carotid bodies evoked hindlimb muscle vasoconstriction. In the post-contraction hyperaemic period, the response was reduced or abolished. A similar attenuation of the reflex vasoconstrictor responses occurred in decentralized muscles stimulated through their motor roots in the cauda equina. 4. Evidence is presented that the attenuation of the vasoconstrictor responses evoked by the two reflexes is a phenomenon localized to the contracting muscles themselves resulting from an interaction between sympathetic neuronal activity and the local production of metabolites. 5. The results are discussed in relation to the metabolic needs of tissues in relation to asphyxial defence mechanisms such as occur in the diving response.  (+info)

Depression of peripheral chemosensitivity by a dopaminergic mechanism in patients with obstructive sleep apnoea syndrome. (5/1554)

In the present study, respiratory drives to chemical stimuli and peripheral chemosensitivity were evaluated in patients with obstructive sleep apnoea (OSAS). The effects of oral administration of domperidone, a selective dopamine D2-receptor antagonist, were also examined, to study the respiratory effects of endogenous dopamine on peripheral chemoreceptors. Sixteen patients with OSAS and nine normal control subjects were studied. Respiratory responses to hypercapnia and hypoxia were measured using the rebreathing method and isocapnic progressive hypoxia method, respectively. The hypoxic withdrawal test, which measures the decrease in ventilation caused by two breaths of 100% O2 under mild hypercapnic hypoxic conditions (end-tidal oxygen and carbon dioxide tensions approximately 8.0 kPa and 5.3-6.7 kPa, respectively), was used to evaluate peripheral chemosensitivity. In the patients with OSAS, ventilatory responses to hypercapnia and hypoxia were significantly decreased compared with those of control subjects. Hypoxic withdrawal tests showed that peripheral chemosensitivity was significantly lower in patients with OSAS than in normal subjects. Hypercapnic ventilatory response and peripheral chemosensitivity were enhanced by administration of domperidone in the patients with OSAS, although no changes in either of these were observed in the control subjects. The hypoxic ventilatory response and peripheral chemosensitivity in the patients with OSAS were each significantly correlated with severity of hypoxia during sleep. These findings suggest that peripheral chemosensitivity in patients with obstructive sleep apnoea syndrome may be decreased as a result of abnormality in dopaminergic mechanisms and that the reduced chemosensitivity observed in patients with obstructive sleep apnoea syndrome may affect the severity of hypoxia during sleep.  (+info)

BDNF is a target-derived survival factor for arterial baroreceptor and chemoafferent primary sensory neurons. (6/1554)

Brain-derived neurotrophic factor (BDNF) supports survival of 50% of visceral afferent neurons in the nodose/petrosal sensory ganglion complex (NPG; Ernfors et al., 1994a; Jones et al., 1994; Conover et al., 1995; Liu et al., 1995; Erickson et al., 1996), including arterial chemoafferents that innervate the carotid body and are required for development of normal breathing (Erickson et al., 1996). However, the relationship between BDNF dependence of visceral afferents and the location and timing of BDNF expression in visceral tissues is unknown. The present study demonstrates that BDNF mRNA and protein are transiently expressed in NPG targets in the fetal cardiac outflow tract, including baroreceptor regions in the aortic arch, carotid sinus, and right subclavian artery, as well as in the carotid body. The period of BDNF expression corresponds to the onset of sensory innervation and to the time at which fetal NPG neurons are BDNF-dependent in vitro. Moreover, baroreceptor innervation is absent in newborn mice lacking BDNF. In addition to vascular targets, vascular afferents themselves express high levels of BDNF, both during and after the time they are BDNF-dependent. However, endogenous BDNF supports survival of fetal NPG neurons in vitro only under depolarizing conditions. Together, these data indicate two roles for BDNF during vascular afferent pathway development; initially, as a target-derived survival factor, and subsequently, as a signaling molecule produced by the afferents themselves. Furthermore, the fact that BDNF is required for survival of functionally distinct populations of vascular afferents demonstrates that trophic requirements of NPG neurons are not modality-specific but may instead be associated with innervation of particular organ systems.  (+info)

Selective potentiation of peripheral chemoreflex sensitivity in obstructive sleep apnea. (7/1554)

BACKGROUND: The chemoreflexes are an important mechanism for regulation of both breathing and autonomic cardiovascular function. Abnormalities in chemoreflex mechanisms may be implicated in increased cardiovascular stress in patients with obstructive sleep apnea (OSA). We tested the hypothesis that chemoreflex function is altered in patients with OSA. METHODS AND RESULTS: We compared ventilatory, sympathetic, heart rate, and blood pressure responses to hypoxia, hypercapnia, and the cold pressor test in 16 untreated normotensive patients with OSA and 12 normal control subjects matched for age and body mass index. Baseline muscle sympathetic nerve activity (MSNA) was higher in the patients with OSA than in the control subjects (43+/-4 versus 21+/-3 bursts per minute; P<0. 001). During hypoxia, patients with OSA had greater increases in minute ventilation (5.8+/-0.8 versus 3.2+/-0.7 L/min; P=0.02), heart rate (10+/-1 versus 7+/-1 bpm; P=0.03), and mean arterial pressure (7+/-2 versus 0+/-2 mm Hg; P=0.001) than control subjects. Despite higher ventilation and blood pressure (both of which inhibit sympathetic activity) in OSA patients, the MSNA increase during hypoxia was similar in OSA patients and control subjects. When the sympathetic-inhibitory influence of breathing was eliminated by apnea during hypoxia, the increase in MSNA in OSA patients (106+/-20%) was greater than in control subjects (52+/-23%; P=0.04). Prolongation of R-R interval with apnea during hypoxia was also greater in OSA patients (24+/-6%) than in control subjects (7+/-5%) (P=0.04). Autonomic, ventilatory, and blood pressure responses to hypercapnia and the cold pressor test in OSA patients were not different from those observed in control subjects. CONCLUSIONS: OSA is associated with a selective potentiation of autonomic, hemodynamic, and ventilatory responses to peripheral chemoreceptor activation by hypoxia.  (+info)

NADPH oxidase inhibition does not interfere with low PO2 transduction in rat and rabbit CB chemoreceptor cells. (8/1554)

The aim of the present work was to elucidate the role of NADPH oxidase in hypoxia sensing and transduction in the carotid body (CB) chemoreceptor cells. We have studied the effects of several inhibitors of NADPH oxidase on the normoxic and hypoxia-induced release of [3H]catecholamines (CA) in an in vitro preparation of intact CB of the rat and rabbit whose CA deposits have been labeled by prior incubation with the natural precursor [3H]tyrosine. It was found that diphenyleneiodonium (DPI; 0.2-25 microM), an inhibitor of NADPH oxidase, caused a dose-dependent release of [3H]CA from normoxic CB chemoreceptor cells. Contrary to hypoxia, DPI-evoked release was only partially Ca2+ dependent. Concentrations of DPI reported to produce full inhibition of NADPH oxidase in the rat CB did not prevent the hypoxic release response in the rat and rabbit CB chemoreceptor cells, as stimulation with hypoxia in the presence of DPI elicited a response equaling the sum of that produced by DPI and hypoxia applied separately. Neopterin (3-300 microM) and phenylarsine oxide (0.5-2 microM), other inhibitors of NADPH oxidase, did not promote release of [3H]CA in normoxic conditions or affect the response elicited by hypoxia. On the basis of effects of neopterin and phenylarsine oxide, it is concluded that NADPH oxidase does not appear to play a role in oxygen sensing or transduction in the rat and rabbit CB chemoreceptor cells in vitro and, in the context of the present study, that DPI effects are not related to NADPH oxidase inhibition.  (+info)

TY - JOUR. T1 - Peripheral chemoreceptor inputs to medullary inspiratory and postinspiratory neurons of cats. AU - Lawson, Edward E.. AU - Richter, Diethelm W.. AU - Ballantyne, David. AU - Lalley, Peter M.. AU - Bischoff, Annemarie. AU - Kühner, Anita. PY - 1989/9/1. Y1 - 1989/9/1. N2 - The effect of peripheral chemoreceptor activation on inspiratory and postinspiratory medullary neurons was investigated using intracellular recording techniques. Peripheral chemoreceptors were activated by injecting CO2 saturated 1 N bicarbonate solution into the lingual artery or by electrically stimulating the carotid sinus nerve. Injections of 20-300 μl bicarbonate solution evoked changes in respiratory frequency and in peak phrenic nerve discharge. The membrane potential of inspiratory alpha neurons, whether bulbospinal or not and independent of their anatomic location, was decreased during inspiration. A sequence of compound excitatory and inhibitory effects were observed when the stimulus was given ...
This study was performed to determine whether stimulation of the carotid chemoreceptors increases total or regional cerebral blood flow and whether activation of arterial chemoreceptors contributes to cerebral vasodilation during systemic hypoxemia. In anesthetized and ventilated dogs, carotid chemoreceptors were stimulated with nicotine or hypoxic and hypercapnic blood. To measure total and regional cerebral blood flow, we used labeled 15-mu microspheres. Stimulation of chemoreceptors did not increase cerebral blood flow or produce significant redistribution of cerebral blood flow, even though the chemoreflex was intact in these animals (as manifested by vasoconstriction in muscle, kidney, and small bowel) and the cerebral vessels dilated in response to systemic hypercapnia. In other studies in anesthetized, ventilated dogs and rhesus monkeys, cerebral vasodilator responses to systemic hypoxemia were observed before and after denervation of carotid and aortic chemoreceptors. Systemic hypoxemia ...
TY - JOUR. T1 - Cellular mechanisms involved in CO2 and acid signaling in chemosensitive neurons. AU - Putnam, Robert W.. AU - Filosa, Jessica A.. AU - Ritucci, Nicola A.. PY - 2004/12. Y1 - 2004/12. N2 - An increase in CO2/H+ is a major stimulus for increased ventilation and is sensed by specialized brain stem neurons called central chemosensitive neurons. These neurons appear to be spread among numerous brain stem regions, and neurons from different regions have different levels of chemosensitivity. Early studies implicated changes of pH as playing a role in chemosensitive signaling, most likely by inhibiting a K+ channel, depolarizing chemosensitive neurons, and thereby increasing their firing rate. Considerable progress has been made over the past decade in understanding the cellular mechanisms of chemosensitive signaling using reduced preparations. Recent evidence has pointed to an important role of changes of intracellular pH in the response of central chemosensitive neurons to increased ...
In contrast to Escherichia coli, a model organism for chemotaxis that has 5 chemoreceptors and a single chemosensory pathway, Pseudomonas aeruginosa PAO1 has a much more complex chemosensory network, which consists of 26 chemoreceptors feeding into four chemosensory pathways. While several chemoreceptors were rigorously linked to specific pathways in a series of experimental studies, for most of them this information is not available. Thus, we addressed the problem computationally. Protein-protein interaction network prediction, coexpression data mining, and phylogenetic profiling all produced incomplete and uncertain assignments of chemoreceptors to pathways. However, comparative sequence analysis specifically targeting chemoreceptor regions involved in pathway interactions revealed conserved sequence patterns that enabled us to unambiguously link all 26 chemoreceptors to four pathways. Placing computational evidence in the context of experimental data allowed us to conclude that three ...
The molecular mechanisms underlying O|sub|2|/sub|-sensing by carotid body (CB) chemoreceptors remain undetermined. Mitochondria have been implicated, due to the sensitivity of CB response to electron transport chain (ETC) blockers. ETC is one of the major sources of reactive oxygen species, proposed …
Read Synaptic excitation and inhibition resulting from direct action of acetylcholine on two types of chemoreceptors on individual amphibian parasympathetic neurones, The Journal of Physiology on DeepDyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips.
Many transmembrane receptors are oligomeric proteins. Binding of a ligand may alter the oligomeric state of the receptor, induce structural changes within the oligomer, or both. The bacterial aspartate chemoreceptor Tar forms a homodimer in the presence or absence of ligands. Tar mediates attractant and repellent responses by modulating the activity of the cytoplasmic kinase CheA. In vivo intersubunit suppression was used to show that certain combinations of full-length and truncated mutant Tar proteins complemented each other to restore attractant responses to aspartate. These results suggest that heterodimers with only one intact cytoplasmic domain are functional. The signaling mechanism may require interactions between dimers or conformational changes within a single cytoplasmic domain.. ...
TY - JOUR. T1 - Human obesity is characterized by a selective potentiation of central chemoreflex sensitivity. AU - Narkiewicz, Krzysztof. AU - Kato, Masahiko. AU - Pesek, Catherine A.. AU - Somers, Virend K.. PY - 1999/5. Y1 - 1999/5. N2 - The chemoreflexes are an important mechanism for regulation of both breathing and autonomic cardiovascular function. Obesity is associated with an increased risk of alveolar hypoventilation and carbon dioxide retention, suggesting that abnormalities in chemoreflex control mechanisms may be implicated. We tested the hypothesis that chemoreflex function is altered in obesity. We compared ventilatory, sympathetic, heart rate, and blood pressure responses to hypercapnia, hypoxia, and the cold pressor test in 14 obese subjects and 14 normal-weight subjects matched for age and gender. During hypercapnia, the increase in minute ventilation was significantly greater in obese subjects (7.0±0.3 L/min) than in normal-weight subjects (3.3±1.1 L/min; P=0.03). Despite ...
human respiratory system - Chemoreceptors: One way in which breathing is controlled is through feedback by chemoreceptors. There are two kinds of respiratory chemoreceptors: arterial chemoreceptors, which monitor and respond to changes in the partial pressure of oxygen and carbon dioxide in the arterial blood, and central chemoreceptors in...
Rationale: Peripheral chemoreflex contributes to regulation of arterial blood pressure and chemoreceptors respond not only to hypoxia but they are also continuously activated by normal ambient oxygen concentration. Stimulation of chemoreceptors activates sympathetic traffic and this response may be altered in subjects with essential hypertension... Objective: The aim of our study was to investigate the effect of deactivation of carotid body chemoreceptors on sympathetic activity directly measured as MSNA (muscle sympathetic nerve activity) in young subjects with mild to moderate untreated hypertension.. Methods: Twelve patients with essential hypertension (36±9 years, all men, BMI 29±4 kg/m2,) and 8 controls (37±7, men BMI 27±5kg/m2) participated in the study. None of the patients or controls received any medications. MSNA (burst/minute and mean burst amplitude - au), systolic blood pressure (SBP) and diastolic blood pressure (DBP), heart rate (HR), ECG, hemoglobin saturation with oxygen ...
Campylobacter jejunis flagellar locomotion is controlled by eleven chemoreceptors. Assessment of the distribution of the relevant chemoreceptor genes in the C. jejuni genomes deposited in the National Center for Biotechnology Information (NCBI) database led to the identification of two previously unknown tlp genes and a tlp5 pseudogene. These two chemoreceptor genes share the same locus in the C. jejuni genome with tlp4 and tlp11, but the gene region encoding the periplasmic ligand binding domain differs significantly from other chemoreceptor genes. Hence, they were named tlp12 and tlp13.. Consequently, it was of interest to study their distribution in C. jejuni subpopulations of different clonality, and their cooccurrence with the eleven previously reported chemoreceptor genes. Therefore, the presence of all tlp genes was detected by polymerase chain reaction (PCR) in 292 multilocus sequence typing (MLST)-typed C. jejuni isolates from different hosts.. The findings show interesting trends: ...
are not able to diffuse across the blood-brain barrier into the CSF. Only CO2 levels affect this as it can diffuse across, reacting with H2O to form carbonic acid and thus decrease pH. Central chemoreception remains, in this way, distinct from peripheral chemoreceptors. The central chemoreception system has also been shown experimentally to respond to hypercapnic hypoxia (elevated CO2, decreased O2) and aqueous sodium cyanide injection into the whole animal[1] and in vitro slice preparation. These methods can be used to mimic some forms of hypoxic hypoxia and they are currently being studied including the detection of variation in arterial CO2 tension acting as a quick-response-system for short term (or emergency) regulation. This system utilizes a negative feedback system, therefore if the pH of the cerebral spinal fluid does not compare to an ideal set level, then the receptor will send an error signal to the effectors and appropriate action may be executed. Peripheral chemoreceptors ...
Synonyms for Chemoreceptors in Free Thesaurus. Antonyms for Chemoreceptors. 9 words related to chemoreceptor: sense organ, sensory receptor, receptor, gustatory organ, taste bud, tastebud, carotid body, nose, olfactory organ. What are synonyms for Chemoreceptors?
Bacteria have evolved a wide range of chemoreceptors with different ligand specificities. Typically, chemoreceptors bind ligands with elevated specificity and ligands serve as growth substrates. However, there is a chemoreceptor family that has a broad ligand specificity including many compounds that are not of metabolic value. To advance the understanding of this family, we have used the PcaY_PP (PP2643) chemoreceptor of Pseudomonas putida KT2440 as a model. Using Isothermal Titration Calorimetry we showed here that the recombinant ligand binding domain (LBD) of PcaY_PP recognizes 17 different C6-ring containing carboxylic acids with KD values between 3.7 and 138 µM and chemoeffector affinity correlated with the magnitude of the chemotactic response. Mutation of the pcaY_PP gene abolished chemotaxis to these compounds; phenotype that was restored following gene complementation. Growth experiments using PcaY_PP ligands as sole C-sources revealed functional relationships between their metabolic
Chemoreceptors are specialized nerve cells designed to respond to chemical stimuli. There are two types of chemoreceptors in the...
Our extensive work in hypertensive animal models indicates that the carotid bodies develop tonicity and heightened reflex sensitivity due to excessive ATP bioavailability acting via purinergic (P2) receptors, which drive sympathetic outflows. We wish to determine whether a non-selective P2 receptor blocker reduces peripheral chemoreflex sensitivity, sympathetic activity, venous tone and blood pressure in humans with hypertension ...
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This double-blind, randomized, vehicle-controlled study indicates that chemoreflex deactivation with hyperoxia decreases MSNA and blood pressure in normoxic, normotensive patients with OSA but not in normal, obese control subjects. Thus, elevated sympathetic nerve activity to muscle in patients with OSA might be explained in part by tonic activation of excitatory chemoreflex afferents.. Studies in animals indicate that tonic chemoreflex activation even during normoxia has significant effects on both blood pressure and heart rate, probably mediated by sympathetic activation.9 Previous studies in humans show that 100% oxygen elicits reductions in MSNA and not blood pressure, but in normal-weight young subjects.6 Another possible explanation for the previously observed decrease in MSNA during 100% oxygen in normal subjects might be acclimation to the laboratory setting and to mouthpiece breathing. In the present study, 100% oxygen decreased MSNA and MAP in both normal obese control subjects and ...
CHEMORECEPTION CONCEPT Chemoreception is a physiological process whereby organisms respond to chemical stimuli. Humans and most higher animals have two principal classes of chemoreceptors: taste (gustatory receptors), and smell (olfactory receptors).
We show CheR2 was the only paralogue that methylated McpB, and deletion of the pentapeptide abolished both the CheR2-McpB interaction and the methylation of McpB. The cheR2 and mcpB genes are vicinal in the P. aeruginosa genome and form part of the gene cluster that encodes the Che2 chemosensory pathway. We conclude that the CheR-pentapeptide interaction enabled the specific targeting of one CheR methyltransferase to one chemoreceptor. We also found that bacterial CheR proteins form two distinct protein families when clustered according to sequence, those that bind pentapeptide-containing chemoreceptors and those that do not, distinguished by an insertion of three amino acids in the β-subdomain of CheR. Deletion of this insertion in CheR2 prevented its interaction with and methylation of McpB. Because many bacteria contain pentapeptide-containing chemoreceptors and several signaling protein paralogues, we predict that the mechanism described may contribute to the specific assembly of signaling ...
Growing evidence shows that sensory cells which enable us to taste sweetness, bitterness and savoriness (umami) are not limited to the tongue. These so-called Trpm5-expressing chemosensory cells are also found in the respiratory ...
2.) Chemoreceptors in the duodenum are stimulated by H+ (low pH) or lipids. Action potentials generated by the chemoreceptors are carried by the vagus nerves to the medulla oblongata (green arrow), where they inhibit parasympathetic action potentials (pink arrow), thereby decreasing gastric secretions ...
The spatial location of proteins in living cells can be critical for their function. For example, the E. coli chemotaxis machinery is localized to the cell poles. Here we describe the polar localization of the serine chemoreceptor Tsr using a strain synthesizing a fluorescent Tsr-Venus fusion at a low level from a single-copy chromosomal construct. Using photobleaching and imaging during recovery by new synthesis, we observed distinct asymmetry between a bright (old) pole and a dim (new) pole. The old pole was shown to be a more stable cluster and to recover after photobleaching faster, which is consistent with the hypothesis that newly synthesized Tsr proteins are inserted directly at or near the old pole. The new pole was shown to be a less stable cluster and to exchange proteins freely with highly mobile Tsr-Venus proteins diffusing in the membrane. We propose that the new pole arises from molecules escaping from the old pole and diffusing to the new pole where a more stable cluster forms ...
There are indeed numerous deaths due to synergistic combinations of sedatives and opioids. This is because sedatives obtund the primary form of respiratory drive, and opioids obtund the secondary form of respiratory drive. If both forms of respiratory drive are blocked, then respiratory drive is abolished altogether, which of course is lethal. The primary form of respiratory drive is affected by pH receptors in brain ventricles, and it determines respiratory rate and depth in conscious individuals. This form of respiratory drive is resistant to hyperventilation and depletion of CO2 tissue reserves so long as consciousnss remains present. During sleep and anesthesia, when consciousness is obtunded, the primary respiratory drive is abolished, and breathing becomes totally dependent on the secondary form of respiratory drive. The secondary form of respiratory drive is primarily determined by respiratory chemoreceptors located in extravascular tissues. These are stimulated directly by hypercarbia, ...
C. elegans STR-8 protein; contains similarity to Pfam domain PF01461 (7TM chemoreceptor)contains similarity to Interpro domains IPR000168 (Nematode 7TM chemoreceptor (probably olfactory)), IPR003002 (7TM chemoreceptor, subfamily 1 ...
1. Salazar ME, Laub MT. Temporal and evolutionary dynamics of two-component signaling pathways. Curr Opin Microbiol. 2015;24: 7-14. doi: 10.1016/j.mib.2014.12.003 25589045. 2. Tian T, Harding A. How MAP kinase modules function as robust, yet adaptable, circuits. Cell Cycle. 2014;13: 2379-2390. doi: 10.4161/cc.29349 25483189. 3. Capra EJ, Perchuk BS, Skerker JM, Laub MT. Adaptive mutations that prevent crosstalk enable the expansion of paralogous signaling protein families. Cell. 2012;150: 222-232. doi: 10.1016/j.cell.2012.05.033 22770222. 4. Jonas K, Chen YE, Laub MT. Modularity of the bacterial cell cycle enables independent spatial and temporal control of DNA replication. Curr Biol. 2011;21: 1092-1101. doi: 10.1016/j.cub.2011.05.040 21683595. 5. Murray SM, Panis G, Fumeaux C, Viollier PH, Howard M. Computational and genetic reduction of a cell cycle to its simplest, primordial components. PLoS Biol. 2013;11: e1001749. doi: 10.1371/journal.pbio.1001749 24415923. 6. Stock AM, Robinson VL, ...
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Daily News How Gaining and Losing Weight Affects the Body Millions of measurements from 23 people who consumed extra calories every day for a month reveal changes in proteins, metabolites, and gut microbiota that accompany shifts in body mass.. ...
Recent studies revealed a high degree of spatial organisation in bacterial cells, and positioning of the chemoreceptor clusters does not appear to be an exception. Lateral clusters are distributed along the cell body in a periodic manner, with the peak positions roughly corresponding to 1/8, 1/4, 3/8, 1/2, 5/8, 3/4, and 7/8 of the distance between polar regions. Such periodicity suggests an anchorage to some hypothetical structure, which is further supported by the apparent immobility of lateral clusters. Our results make it unlikely that this structure relies directly on either the Min septum positioning system or the MreB cytoskeleton, although cluster positioning was affected by a loss of the rod shape upon a long‐term treatment with the MreB inhibitor A22. At the current stage, we can only speculate about the nature of this structure. Many protein complexes in bacteria appear to localise along helical filaments, and it has been recently shown that receptors become inserted into the ...
Bairam A, Dauphin C, Rousseau F, Khandjian EW. Expression of dopamine D2-receptor mRNA isoforms at the peripheral chemoreflex afferent pathway in developing rabbits. Am J Respir Cell Mol Biol. 1996;15(3):374-81. ...
TY - JOUR. T1 - Gene transfer of neuronal nitric oxide synthase to carotid body reverses enhanced chemoreceptor function in heart failure rabbits. AU - Li, Yulong. AU - Li, Yi Fan. AU - Liu, Dongmei. AU - Cornish, Kurtis G.. AU - Patel, Kaushik P. AU - Zucker, Irving H. AU - Channon, Keith M.. AU - Schultz, Harold D. PY - 2005/8/5. Y1 - 2005/8/5. N2 - Our previous studies showed that decreased nitric oxide (NO) production enhanced carotid body (CB) chemoreceptor activity in chronic heart failure (CHF) rabbits. In the present study, we investigated the effects of neuronal NO synthase (nNOS) gene transfer on CB chemoreceptor activity in CHF rabbits. The nNOS protein expression and NO production were suppressed in CBs (P,0.05) of CHF rabbits, but were increased 3 days after application of an adenovirus expressing nNOS (Ad.nNOS) to the CB. As a control, nNOS and NO levels in CHF CBs were not affected by Ad.EGFP. Baseline single-fiber discharge during normoxia and the response to hypoxia were ...
Afferent chemoreceptor activity was recorded from the peripheral cut end of the carotid sinus nerve in pentobarbitone anaesthetized cats. The effects of purines, peptides and ouabain on chemosensory activity were studied. Purines. It was found that intracarotid injections of adenosine: AMP; ADP; ATP; CoA;Me-adenosine analogues: N6-methyladenosine, 2-chloroadenosine, 3-deoxyudenosine but not 2-deoxyadenosine; cyclic AMP; dibutyryl cyclic AMP increased spontaneous chemoreceptor discharge. The ATP analogues, a-5- methylene ATP decreased spontaneous chemoreceptor discharge, whereas the f-y-methylene ATP caused a slight increase in discharge. Adenine and the purine nucleosides inosine and guanosine had little or no effect on the discharge. The pyrimidine nucleosides cytidine and uridine were also studied and had little or no effect on spontaneous chemoreceptor discharge. Intracarotid injection of theophylline transiently depressed spontaneous chemosensory activity and potentiated the action of ...
The major new finding obtained from conscious rats was the clear-cut demonstration that chemoreceptors, as well as baroreceptors, were transiently activated during combined electric stimulation of the carotid sinus and the carotid sinus nerve in conscious rats. The results have shown that when the carotid bifurcation was intact (ie, in the CONT group), combined electric stimulation of the carotid sinus and the carotid sinus nerve elicited a significant hypotensive response. This finding is in line with results obtained in dogs21,22 and drug-resistant hypertensive patients.1,2 Nevertheless, unlike the results seen in dogs23 and drug-resistant hypertensive patients,4 HR did not significantly decrease in intact conscious rats (the CONT group).. It is of interest to note that bilateral carotid body denervation (as in the CHEMO-X group) hampered the hemodynamic influences of the carotid chemoreceptors during combined electric stimulation of the carotid sinus and the carotid sinus nerve in conscious ...
TY - GEN. T1 - Bicarbonate-regulated soluble adenylyl cyclase (sAC) mRNA expression and activity in peripheral chemoreceptors. AU - Nunes, A. R.. AU - Monteiro, E. C.. AU - Johnson, S. M.. AU - Gauda, E. B.. PY - 2009/12. Y1 - 2009/12. N2 - Peripheral arterial chemoreceptors in the carotid body (CB) are modulated by pH/CO2. Soluble adenylyl cyclase (sAC) is directly stimulated by bicarbonate ions (HCO3 -). Because CO2/HCO 3 - mediates depolarization in chemoreceptors, we hypothesized that sAC mRNA would be expressed in the CB, and its expression and function would be regulated by CO2/HCO3 -. Sprague-Dawley rats at postnatal days 16-17 were used to compare sAC mRNA gene expression between CB and non-chemosensitive tissues: superior cervical (SCG), petrosal (PG) and nodose ganglia (NG) by quantitative real time-PCR. Rat sAC gene expression was standardized to the expression of GAPDH (housekeeping gene) and the data were analyzed with the Pfaffl method. Gene and protein expression, and sAC ...
TY - JOUR. T1 - Ventilation- and carotid chemoreceptor discharge-response to hypoxia during induced hypothermia in halothane anesthetized rat. AU - Maruyama, Ryoko. AU - Fukuda, Yasuichiro. N1 - Copyright: Copyright 2017 Elsevier B.V., All rights reserved.. PY - 2000/2. Y1 - 2000/2. N2 - It has been hypothesized that respiratory gain to hypoxic stimulus is not depressed in hypothermic animals though ventilation and that metabolic O2 demand (VO2) decreases with reduction in body temperature. The present study addressed this hypothesis by quantitative analysis of ventilatory and carotid chemoreceptor responsiveness to hypoxia during induced hypothermia in halothane anesthetized and spontaneously breathing rats. Rectal temperature was lowered from 37 °C (normothermia) to 30 and 25 °C by cooling body surface at comparable anesthetic depth without inducing shivering. Ventilation (VE), VO2, Pao2 and carotid chemoreceptor afferent discharges were measured during hyperoxic and hypoxic gas breathing. ...
The study was approved by the Local Animal Care and Use Committee of the Karolinska Institute, Stockholm, Sweden. Seven adult New Zealand White rabbits weighing 3860 +/− 270 g (mean +/− SD) were included. After an initial dose of intravenous thiopental, 75-100 mg, given via a marginal ear vein, a tracheostomy was performed after an anterior midline skin incision. Mechanical ventilation (ETCO(2), 4.0-5.0%) was initiated at a rate of 33 breaths/min using a mixture of oxygen and air (FIO(2) 0.30), whereas the inspired tidal volume was adjusted to maintain isocapnia throughout the experiment. Anesthesia was maintained with a continuous thiopental infusion of 10.5 +/− 0.9 mg [middle dot] kg-1[middle dot] h-1(range, 9.4-12.0) given via a right femoral vein catheter. The right femoral artery was cannulated for continuous arterial blood pressure monitoring and arterial blood gas analysis (ABL 300 Laboratory [registered sign], Radiometer, Copenhagen, Denmark). On-line analysis of inspired and ...
Looking for chemoreceptive? Find out information about chemoreceptive. The ability of organisms to detect changes in the chemical composition of their exterior or interior environment. It is a characteristic of every living... Explanation of chemoreceptive
Background. Peripheral chemoreceptors residing predominantly in the carotid body monitor changes in arterial blood oxygen and are mechanistically linked to the cardiorespiratory control by the autonomic nervous system. Enhanced sympathetic activation is common in end-stage renal disease and kidney transplantation has been shown to improve cardiorespiratory reflex measures of autonomic function.. Objective. The aim of the present study was to test whether improvement in renal function following kidney transplantation is related to an improvement in chemosensory function.. Methods and Results. We compared hyperoxic chemoreflex sensitivity (CHRS) in patients after renal transplantation (RTX) to that in patients on maintenance hemodialysis (HD), and that of age- and gender-matched healthy controls. In addition, we investigated the impact of common confounding factors including pharmacological neurohumoral modulation and diabetes mellitus. The difference in the R-R intervals divided by the difference ...
The pH of the extracellular fluids can thus be controlled by separately regulating the partial pressure of carbon dioxide (which determines the carbonic acid concentration), and the bicarbonate ion concentration in the extracellular fluids. There are therefore at least two homeostatic negative feedback systems responsible for the regulation of the plasma pH. The first is the homeostatic control of the blood partial pressure of carbon dioxide, which determines the carbonic acid concentration in the plasma, and can change the pH of the arterial plasma within a few seconds.[5] The partial pressure of carbon dioxide in the arterial blood is monitored by the central chemoreceptors of the medulla oblongata, and so are part of the central nervous system.[5][19] These chemoreceptors are sensitive to the pH and levels of carbon dioxide in the cerebrospinal fluid.[13][11][19] (The peripheral chemoreceptors are located in the aortic bodies and carotid bodies adjacent to the arch of the aorta and to the ...
Site-specific mutagenesis was used to replace an alanine with a lysine residue and to create a deletion of seven amino acids into the first transmembrane region (TMI region) of the aspartate chemoreceptor in Escherichia coli. The mutations resulted in the loss of aspartate chemotaxis on tryptone motility plates. However, both mutant proteins were able to associate with the membrane and to bind aspartate. They were both refractory to methylation or to modification of the C-terminal region of the protein by the cheB gene product. These results suggested that the integrity of the TMI domain of the protein was required to maintain the function of the cytoplasmic portion of the receptor. The Lys-19 mutant retained the ability to generate a repellent response. Analysis of suppressor mutations of the Lys-19 mutation suggested that formation of an ion pair or specific changes in a 40 amino acid stretch in the cytoplasmic region of the protein (from amino acid 264 to amino acid 303) could suppress the ...
The carotid body (CB) is the main arterial chemoreceptor in charge of adjusting ventilatory and cardiovascular function during changes in arterial blood gases. Regardless this essential function, the CB has been implicated in the sensing of other physiological signals such as changes in blood flow and glucose levels. More important, malfunction of the CB chemoreceptors has been associated with the progression and deterioration of several disease states such as hypertension, heart failure, renal failure, insulin resistance, diabetes and sleep apnea. Although the mechanisms involved in the alterations of the CB function in pathophysiology are currently under intense research, the development of therapeutic approaches to restore normal CB chemoreflex function remains unsolved. Recently, elegant studies showing the effect of CB neurotomy in pathophysiology have unveiled a key role of these arterial chemoreceptors in the development of autonomic imbalance and respiratory disturbances, and suggest that
TY - JOUR. T1 - Cholinergic chemosensory cells in the trachea regulate breathing. AU - Krasteva, Gabriela. AU - Canning, Brendan J. AU - Hartmann, Petra. AU - Veres, Tibor Z.. AU - Papadakis, Tamara. AU - Mühlfeld, Christian. AU - Schliecker, Kirstin. AU - Tallini, Yvonne N.. AU - Braun, Armin. AU - Hackstein, Holger. AU - Baal, Nelli. AU - Weihe, Eberhard. AU - Schütz, Burkhard. AU - Kotlikoff, Michael. AU - Ibanez-Tallon, Ines. AU - Kummer, Wolfgang. PY - 2011/6/7. Y1 - 2011/6/7. N2 - In the epithelium of the lower airways, a cell type of unknown function has been termed brush cell because of a distinctive ultrastructural feature, an apical tuft of microvilli. Morphologically similar cells in the nose have been identified as solitary chemosensory cells responding to taste stimuli and triggering trigeminal reflexes. Here we show that brush cells of the mouse trachea express the receptors (Tas2R105, Tas2R108), the downstream signaling molecules (α-gustducin, phospholipase Cβ2) of bitter ...
The basic rythum of breathing is controlled by respiratory centers located in the medulla and pons of the brainstem. This rythum is modified in response to input from sensory receptors and from other regions of the brain. Respiratory centers in the pons modify inspiration and allow for smooth transitions between inspiration and expiation. Expiratory centers in the medulla function during forced expiation stimulating the internal and abdominal muscles. The basic rythum of breathing is modified by input from the central and peripheral chemoreceptors. They respond to changes in the PCO2 and PO2 of arterial blood. Medullary chemoreceptors are located on the ventral surface of the medulla oblongata. The medullary chemoreceptors detect changes to the H+ concentration of the brain interstitial fluid, an indirect assessment of arterial PCO2. Chemoreceptors in the carotid and aortic bodies are stimulated by a rise in the PCO2, a rise in the H+ concentration, or a decline in arterial blood PO2. Peripheral ...
KEY POINTS: The carotid body is a peripheral arterial chemoreceptor that regulates ventilation in response to both acute and sustained hypoxia. Type I cells in this organ respond to low oxygen both acutely by depolarization and dense core vesicle secretion and, over the longer term, via cellular proliferation and enhanced ventilatory responses. Using lineage analysis, the present study shows that the Type I cell lineage itself proliferates and expands in response to sustained hypoxia. Inactivation of HIF-2α in Type I cells impairs the ventilatory, proliferative and cell intrinsic (dense core vesicle) responses to hypoxia. Inactivation of PHD2 in Type I cells induces multilineage hyperplasia and ultrastructural changes in dense core vesicles to form paraganglioma-like carotid bodies. These changes, similar to those observed in hypoxia, are dependent on HIF-2α. Taken together, these findings demonstrate a key role for the PHD2-HIF-2α couple in Type I cells with respect to the oxygen sensing functions
The control of ventilation refers to the physiological mechanisms involved in the control of breathing, which is the movement of air into and out of the lungs. Ventilation facilitates respiration. Respiration refers to the utilization of oxygen and removal of carbon dioxide by the body as a whole, or by individual cells in cellular respiration. The most important function of breathing is the supplying of oxygen to the body and the removal of its waste product of carbon dioxide. Under most conditions, the partial pressure of carbon dioxide (PCO2) or concentration of carbon dioxide, controls the respiratory rate. The peripheral chemoreceptors that detect changes in the levels of oxygen and carbon dioxide are located in the arterial aortic bodies and the carotid bodies. Central chemoreceptors are primarily sensitive to changes in the pH in the blood, (resulting from changes in the levels of carbon dioxide) and they are located on the medulla oblongata near to the medullar respiratory groups of the ...
Abstract. The carotid body (CB) is in charge of adjusting ventilatory and cardiovascular function during changes in arterial blood gases. Regardless this essential function, the CB has been implicated in the sensing of other physiological signals such as changes in blood flow and glucose levels. More important, malfunction of the CB chemoreceptors has been associated with the progression and deterioration of several disease states such as hypertension, heart failure, renal failure, insulin resistance, diabetes and sleep apnea. Although the mechanisms involved in the alterations of the CB function in pathophysiology are currently under intense research, the development of therapeutic approaches to restore normal CB chemoreflex function remains unsolved. Recent studies showing the effect of CB denervation in pathophysiology have unveiled a key role of these arterial chemoreceptors in the development of autonomic imbalance and respiratory disturbances, and suggest that targeting the CB could ...
Monitored by peripheral chemoreceptors - carotid/aortic bodies. Not sensitive to modest changes in PO2. Arterial PO2 must be , 60 mmHg (40% reduction) for chemoreceptors to send afferent impulses to medullary inspiratory neurons. (happens with severe pulmonary disease, reduced atmospheric pressure). Until you get to 60 mmHg, youre still in plateau range of Hb-O2 dissociation curve (safe). If it werent for peripheral chemoreceptors, the low PO2 would depress respiratory centers à stop breathing. Chemoreceptors respond to PO2, not oxygen content. Anemia, CO poisoning - PO2is normal, but total O2 is too low. ...
Chemosensory receptors are essential for the survival of organisms that range from bacteria to mammals. Recent studies have shown that the numbers of functional chemosensory receptor genes and pseudogenes vary enormously among the genomes of different animal species. Although much of the variation can be explained by the adaptation of organisms to different environments, it has become clear that a substantial portion is generated by genomic drift, a random process of gene duplication and deletion. Genomic drift also generates a substantial amount of copy-number variation in chemosensory receptor genes within species. It seems that mutation by gene duplication and inactivation has important roles in both the adaptive and non-adaptive evolution of chemosensation.
My research focus is the neural control of breathing in human and nonhuman mammals. My earlier work assessed the role of pulmonary stretch receptors and central chemoreceptors in the genesis and relief of dyspnea or shortness of breath in healthy adults. These studies led to studies in the mammalian (rodent) airway that explored the modulation of upper airway muscles activities by chemical and pulmonary afferent feedback and the potential for selective electrical stimulation of the cranial nerve XII to alter airway geometry and volume (NIH/NIDCD RO3). Beginning in 2005, with the support of an NIH/NIDCD K23 I began work in neural control of upper airway muscles using tungsten microelectrodes to record from single motor units in adult human subjects. This work led in turn, to studies of regional (or segmental) muscle and motor unit activities in human subjects under volitional, state-dependent (i.e., wake/sleep) and chemoreceptor drives, in health and disease (NIH/NIDCD RO1). On the basis of the ...
N-Formylation and N-methylation of the alpha-amino group of L-phenylalanine result in extremely decreased responses of the labellar sugar receptor of the fleshfly, whereas the same structural alteration of L-valine hardly affects the response. Methyl esterification of the alpha-carboxyl group of phenylalanine, on the other hand, maintains the response to some extent, but similar treatment of valine completely diminishes the response. The aromatic structure in phenylalanine is not essential for stimulation. These results suggest a substantial difference in the stereospecificities and functional group specificities of the furnase (F) and aliphatic carboxylate (T) sites in the sugar receptor. The effect of small peptides on the sugar receptor was examined systematically. Their effectiveness depends mainly on the place of the constituent amino acids rather than on their composition, indicating the decisive role that certain aliphatic amino acids in the C-terminal position play in stimulation. ...
The results from these studies demonstrate that afferent input from peripheral chemoreceptors and mechanoreceptors contributes little to the systemic hemodynamic and sympathetic responses after term delivery by cesarean section. Furthermore, birth-related increases in circulating norepinephrine but not epinephrine appear dependent on afferent input from the carotid sinus or aortic depressor nerves, which carry both chemo- and baroreceptor afferents from the carotid sinus and aortic arch, respectively. Finally, we observed that vagal afferent activity regulates basal fetal plasma ANG II levels and exerts a tonic inhibitory effect on AVP release after birth.. Both peripheral chemoreceptors and baroreceptors have been shown to be functional during fetal life. The fetal cardiovascular response to acute hypoxemia is well described, consisting of a decrease in heart rate and increase in peripheral vascular resistance (7). Carotid denervation abolishes these responses to hypoxemia and NaCN, a chemical ...
Haldane and Priestley (1905) discovered that the ventilatory control system is highly sensitive to CO2. This CO2 chemoreflex has been interpreted to dominate control of resting arterial PCO2/pH (PaCO2/pHa) by monitoring PaCO2/pHa and altering ventilation through negative feedback. However, PaCO2/pHa varies little in mammals as ventilation tightly couples to metabolic demands, which may minimize chemoreflex control of PaCO2. The purpose of this synthesis is to (1) interpret data from experimental models with meager CO2 chemoreflexes to infer their role in ventilatory control of steady-state PaCO2, and (2) identify physiological causes of respiratory acidosis occurring normally across vertebrate classes ...
Soluble proteins containing 4 conserved cysteines which abundantly exist in the chemoreceptive organs and transmit chemical signals to nervous system . The CSP
This review introduces the self-oscillating behavior of two types of nonthermoresponsive polymer systems with Ru catalyst moieties for the Belousov-Zhabotinsky (BZ) reaction: one with a poly-vinylpyrrolidone (PVP) main chain, and the other with a poly(2-propenamide) (polyacrylamide) (PAM) main chain. The amplitude of the VP-based self-oscillating polymer chain and the activation energy for self-oscillation are hardly affected by the initial concentrations of the BZ substrates. The influences of the initial concentrations of the BZ substrates and the temperature on the period of the swelling-deswelling self-oscillation are examined in detail. Logarithmic plots of the period against the initial concentration of one BZ substrate, when the concentrations of the other two BZ substrates are fixed, show good linear relationships. The period of the swelling-deswelling self-oscillation decreases with increasing temperature, in accordance with the Arrhenius equation. The maximum frequency (0.5 Hz) of the poly(VP
Single nucleotide polymorphisms (SNPs) are single nucleotide variations which comprise the most wide spread source of genetic diversity in the genome. Currently, SNPs serve as markers for genetic predispositions, clinically evident disorders and diverse drug responses. Present SNP diagnostics are primarily based on enzymatic reactions in different formats including sequencing, polymerase-chain reaction (PCR) and microarrays. In these assays, the enzymes are applied to address the required sensitivity and specificity when detecting SNP. On the other hand, the development of enzyme-free, simple and robust SNP sensing methods is in a constant focus in research and industry as such assays allow rapid and reproducible SNP diagnostics without the need for expensive equipment and reagents. An ideal method for detection of SNP would entail mixing a DNA or RNA target with a probe to directly obtain a signal. Current assays are still not fulfilling these requirements, although remarkable progress has been
The 9th Catalysis and Sensing for our Environment Symposium (CASE 2019) and 2nd C5 Symposium on Supramolecular Chemistry will be held in Xian 14-16 April 2019 at Northwest A&F University http://en.nwsuaf.edu.cn/events/87816.htm http://en.nwsuaf.edu.cn/events/87815.htm. ...
The carotid body located in the bifurcation of the carotid arteries is able to detect gas changes in blood composition (PO2, PCO2/pH) and to transduce them into afferent nerve signal. The intimate...
An increase in the internal diameter of an artery, triggered by vasomotor suppression, during the chemoreceptor response to decreased blood pressure.
CO2/H+-dependent purinergic signaling by astrocytes provides specialized control of vascular tone in a brainstem respiratory center in a manner that contributes to respiratory behavior.
CO2/H+-dependent purinergic signaling by astrocytes provides specialized control of vascular tone in a brainstem respiratory center in a manner that contributes to respiratory behavior.
how to activate medulla oblongata Review of the functional areas of the brain part 1 by professor fink Central chemoreceptors respiratory system physiology nclex rn khan academy Midbrain, simplified sections of internal structure Baroreflex regulation of blood pressure, animation.
Bargmann, C., Callaway, E., Chklovskii, D. (2010) NEURONAL CIRCUITS. In: 2010 Meeting of Neuronal Circuits, March 10-March 13, 2010, Cold Spring Harbor Laboratory. ...
Chapter 22. Respiratory System. Overview. Respiratory anatomy Respiration Respiratory musculature Ventilation, lung volumes and capacities Gas exchange and transport O 2 CO 2 Respiratory centers Chemoreceptor reflexes Respiratory Diseases. Oxygen. Slideshow 163870 by benjamin
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a research laboratory at UCF College of Medicine in Lake Nona, FL devoted to the basic cellular, molecular and behavioral analyses of nutrient chemoreception
Each olfactory receptor cell expresses only one type of olfactory receptor (OR), but many separate olfactory receptor cells ... Chemoreceptor Sensory receptor Berkowicz, D. A.; Trombley, P. Q.; Shepherd, G. M. (1994). "Evidence for glutamate as the ... opens ion channels in the cell membrane, resulting in an influx of sodium and calcium ions into the cell, and an efflux of ... The cell bodies of the ORNs are distributed among all three of the stratified layers of the olfactory epithelium. Many tiny ...
The pineal body also has photoreceptive cells which, though regressed, retain visual pigment like the photoreceptive cells of ... Chemoreceptors[edit]. The front part of the olm's head carries sensitive chemo-, mechano-, and electroreceptors. ... The complex functional-morphological orientation of the sensory cells enables the animal to register the sound sources.[24][25] ... The spermatophore sticks to her and the sperm cells swim inside her cloaca where they attempt to fertilize her eggs. The ...
The organs are usually mechanoreceptors or chemoreceptors, in some cases located on short tentacles. The chemoreceptor cells ... Large areas of a sea or lake may change colour as a result of the proliferation of millions of single-cell algae, and this ... These consist of a pit of photosensory cells and a lens. Scallops have more complex eyes with a lens, a two-layered retina, and ... The osphradium is a patch of sensory cells located below the posterior adductor muscle that may serve to taste the water or ...
The 5-HT receptors, the receptors for serotonin, are located on the cell membrane of nerve cells and other cell types in ... This activates 5-HT3 receptors in the chemoreceptor trigger zone that stimulate vomiting. Thus, drugs and toxins stimulate ... These studies of Yadav et al., Cell 2008, Nat Med 2010 and more recently Sugisawa et al., Cell 2019 have opened a new area of ... Serotonin can also be synthesized, albeit at very low levels, in the bone cells. It mediates its actions on bone cells using ...
"Postnatal development of E-4031-sensitive potassium current in rat carotid chemoreceptor cells". Journal of Applied Physiology ... Reducing IKr in myocardial cells prolongs the cardiac action potential and thus prolongs the QT-interval. In non-cardiac cells ... hERG channels (Kv11.1) mediate the IKr current, which repolarizes the myocardial cells. The hERG channel is encoded by ether-a- ... GH3/B6 cells)". Pflügers Arch - Eur J Physiol. 434 (1): 1-10. doi:10.1007/s004240050356. PMID 9094250. S2CID 10233500. ...
2003). "Solitary chemoreceptor cells in the nasal cavity serve as sentinels of respiration". Proc Natl Acad Sci U S A. 100 (15 ... The respiratory passages, including the nose and trachea, possess specialized cells called solitary chemosensory cells which ... 2011). "Cholinergic chemosensory cells in the trachea regulate breathing". Proc Natl Acad Sci U S A. 108 (23): 9478-83. Bibcode ... Alternatively, irritant chemicals may activate cells of the epithelium to release substances that indirectly activate the nerve ...
The carotid body is made up of two types of cells, called glomus cells: glomus type I cells are peripheral chemoreceptors, and ... The carotid body is a small cluster of chemoreceptor cells, and supporting sustentacular cells. The carotid body is located in ... Glomus type II cells resemble glial cells, express the glial marker S100 and act as supporting cells. The carotid body ... This leads to depolarisation of the cell membrane which leads to Ca2+ entry, excitation of glomus cells and consequent ...
Cells. *Photoreceptor cells (Cone cell, Rod cell) → (Horizontal cell) → Bipolar cell → (Amacrine cell) → Retina ganglion cell ( ... Chemoreceptors[edit]. Main article: Chemoreceptor. Chemoreceptors, or chemosensors, detect certain chemical stimuli and ... Parasol cell, Bistratified cell, Giant retina ganglion cells, Photosensitive ganglion cell) → Diencephalon: P cell, M cell, K ... The two primary types of chemoreceptors are:. *Distance chemoreceptors are integral to receiving stimuli in the olfactory ...
However, even photoreceptor cells may have evolved more than once from molecularly similar chemoreceptor cells. Probably, ... These photoreceptor cells form part of the retina, a thin layer of cells that relays visual information, including the light ... The basic light-processing unit of eyes is the photoreceptor cell, a specialized cell containing two types of molecules bound ... heavily pigmented retina cells, which shield the light-sensitive cells from exposure in all directions except for the single ...
Each haploid yeast cells express specific haploid genes; haploid α-cells express α-genes and haploid a-cells express a-genes. ... Chemotaxis Chemoreceptor Mechanism Turrà, D., El Ghalid, M., Rossi, F. and Di Pietro, A. (2015). Fungal pathogen uses sex ... When the cells get two Yeast cells are close enough their fungal hyphae merge to form a diploid zygote. Other examples of ... Song, Hong-jun; Poo, Mu-ming (March 2001). "The cell biology of neuronal navigation". Nature Cell Biology. 3 (3): E81-E88. doi: ...
Neuroepithelial cells (NEC) are thought to be neuron-like chemoreceptor cells because they rely on membrane potential changes ... Whereas, if the post-synaptic cell is a connective pillar cell or a vascular smooth muscle cell, then the serotonin will cause ... In fish, the neuroepithelial cells (NEC) have been implicated as the major oxygen sensing cells. NEC have been found in all ... there are two main hypotheses for the location of oxygen sensing in chemoreceptor cells: the membrane hypothesis and the ...
They consist of glomus cells and sustentacular cells. Some sources equate the "aortic bodies" and "paraaortic bodies", while ... The aortic bodies are collections of chemoreceptors present on the aortic arch. Most are located above the aortic arch, while ... The aortic bodies are one of several small clusters of peripheral chemoreceptors located along the aortic arch. They are ... They are more sensitive detectors of arterial blood oxygen content than the carotid body chemoreceptors. The aortic bodies give ...
The gustatory (taste) cells, which are chemoreceptors, occupy the central portion of the bud; they are spindle-shaped, and each ... The bud is formed by two kinds of cells: supporting cells and gustatory cells. The supporting (sustentacular cells) are mostly ... These are located on top of the taste receptor cells that constitute the taste buds. The taste receptor cells send information ... Taste buds contain the taste receptor cells, which are also known as gustatory cells. The taste receptors are located around ...
No specialized sense organs are present but sensory cells include nematocytes and chemoreceptors. The muscles and nerves are ... Cells in the outer layer (epidermis) and the inner layer (gastrodermis) have microfilaments that group into contractile fibers ... A touch to the hair mechanically triggers a cell explosion, which launches a harpoon-like structure that attaches to the ... Since the anemone lacks a rigid skeleton, the contractile cells pull against the fluid in the gastrovascular cavity, forming a ...
They are neuroendocrine cells, the former with primary endocrine functions and the latter with primary chemoreceptor functions ... paraganglia) is a group of non-neuronal cells derived of the neural crest. They are named for being generally in close ... They are essentially of two types: (1) chromaffin or sympathetic paraganglia made of chromaffin cells and (2) nonchromaffin or ... Nonchromaffin paragangliomas are issued from glomus cells, also known as glomus tumors. They are usually benign. They are ...
Van Lommel, A (June 2001). "Pulmonary neuroendocrine cells (PNEC) and neuroepithelial bodies (NEB): chemoreceptors and ... ciliated cells, basal cells, and in the terminal bronchioles-club cells with actions similar to basal cells, and macrophages. ... and dendritic cells which present antigens to activate components of the adaptive immune system such as T-cells and B-cells. ... Despite this, cells occur in a roughly equal ratio of 1:1 or 6:4. Type I are squamous epithelial cells that make up the ...
One example uses chemoreceptor cells of mollusks and similar animals to monitor their coastal and fresh water habitats. ...
Crustaceans have chemoreceptors on the antennules. They can sample chemical signals around them by flicking their antennas and ... It is suggested that the multi-ciliated cells around the rim of their nasal cavities generate a water flow to increase chemical ...
The cell bodies of these neurons reside in the inferior glossopharyngeal ganglion. The central processes of these neurons enter ... This component of CN IX innervates the baroreceptors of the carotid sinus and chemoreceptors of the carotid body. ... These peripheral processes have their cell body in either the superior or inferior glossopharyngeal ganglion.. Central course. ... Its superior and inferior (petrous) ganglia contain the cell bodies of pain fibers. It also projects into many different ...
Via cranial and spinal nerves, the different types of sensory receptor cells (mechanoreceptors, photoreceptors, chemoreceptors ... Receptor cells can be classified into types on the basis of three different criteria: cell type, position, and function. ... The different types of functional receptor cell types are mechanoreceptors, photoreceptors, chemoreceptors (osmoreceptor), ... plants interpret and respond to these stimuli by a variety of hormonal and cell-to-cell communication pathways that result in ...
They bind to cells such as fibroblasts, macrophages, endothelial cells, and kidney epithelial cells. They also bind to several ... Chemoreceptors at the poles of the bacteria sense various substrates and change the direction of its movement. The bacteria are ... complex network of proteins and carbohydrates present between cells). The bacteria use their flagella for moving between cell ... For those who are infected, a complete blood count may show a high white cell count and a low platelet count. When a low ...
Cell Survival and Cell Death". International Journal of Cell Biology. 2010: 214074. doi:10.1155/2010/214074. ISSN 1687-8876. ... In humans, hypoxia is detected by the peripheral chemoreceptors in the carotid body and aortic body, with the carotid body ... Histotoxic hypoxia results when the quantity of oxygen reaching the cells is normal, but the cells are unable to use the oxygen ... If oxygen delivery to cells is insufficient for the demand (hypoxia), electrons will be shifted to pyruvic acid in the process ...
The tentacles may act as chemoreceptors and may also have primitive eyes, simple light-sensitive cells, on them. The Polyclad ... The cells and the pigments they contain that are responsible for this coloring have not been well-studied, but one common ... "The true colours of the flatworm: Mechanisms of pigment biosynthesis and pigment cell lineage development in planarians". ... Seminars in Cell & Developmental Biology. 87: 37-44 - via ScienceDirect. Ang, Hing; Newman, Leslie. "Warning colouration in ...
The externally oriented side of the cell has a hair-like trigger called a cnidocil, which is a mechano- and chemo-receptor. ... In Hydra polyps, cnidocytes differentiate from a specific population of stem cells, the interstitial cells (I-cells) located ... "Cnidarian Cell Type Diversity and Regulation Revealed by Whole-Organism Single-Cell RNA-Seq". Cell. 173 (6): 1520-1534.e20. doi ... containing several types of cnidocytes connected to supporting cells and neurons. The supporting cells contain chemosensors, ...
Sensory cells known as "sensills" on the "lips" or labrum respond to chemical stimuli and are known as chemoreceptors. These ... The retina comprises numerous pigment cells and photoreceptors; the latter are easily modified flagellated cells, whose ... The body wall consists of a non-cellular outer skin, the cuticula; a single layer of epidermis cells forming an internal skin; ... Unlike a true coelom, a pseudocoel is not fully enclosed by a cell layer derived from the embryonic mesoderm. A coelom is, ...
Gustatory cells form on taste buds, specialized epithelial cells, and are generally turned over every ten days. From each cell ... Chemoreceptors and mechanorceptors, activated by chewing and swallowing, further increase the enzyme release in the stomach and ... Such is the case in olfactory cells. Depolarization in these cells result from opening of non-selective cation channels upon ... Janmey, Paul A.; McCulloch, Christopher A. (2007). "Cell Mechanics: Integrating Cell Responses to Mechanical Stimuli". Annual ...
These adult stem cells are called endoblasts, and comprise 20% or more of the cells in the adult animal. They are the only ... The triclads have an anterior end or head where sense organs, such as eyes and chemoreceptors, are usually found. Some species ... The excretory system is made of many tubes with many flame cells and excretory pores on them. Also, flame cells remove unwanted ... Planarians have a number of cell types, tissues and simple organs that are homologous to our own cells, tissues and organs. ...
ChemoreceptorsEdit. Main article: Chemoreceptor. Chemoreceptors, or chemosensors, detect certain chemical stimuli and transduce ... "Histochemistry and Cell Biology. 129 (6): 687-693. doi:10.1007/s00418-008-0416-9. PMC 2386530. PMID 18365235.. ... The two primary types of chemoreceptors are: *Distance chemoreceptors are integral to receiving stimuli in gases in the ... Direct chemoreceptors that detect stimuli in liquids include the taste buds in the gustatory system as well as receptors in the ...
Parts of cells, rather than parts of the body, can also behave as trigger zones. The axon hillock of a neuron possesses the ... The chemoreceptor trigger zone is an area of the medulla oblongata in which many types of chemical stimulation can provoke ... In neuroscience and neurology, a trigger zone is an area of the body, or of a cell, in which a specific type of stimulation ... H. L. Borison, K. R. Brizzee (1951). "Morphology of emetic chemoreceptor trigger zone in cat medulla oblongata". Proceedings of ...
... has been known to stimulate cell growth in normal and cancer cell line cultures,[37] and it was shown that ... SP is released when toxicants or poisons come into contact with a range of receptors on cellular elements in the chemoreceptor ... on cells (including cancer cells) bestowing upon them mobility.[40] and metastasis.[41] It has been suggested that cancer ... stem cells, white blood cells) in many tissues and organs. SP amplifies or excites most cellular processes.[15][16] ...
The skin consists of a thin outer epidermis with mucous cells and sensory cells, and a connective tissue dermis consisting ... The octopus's suction cups are equipped with chemoreceptors so the octopus can taste what it touches. Octopus arms do not ... Other colour-changing cells are reflective iridophores and white leucophores.[93] This colour-changing ability is also used to ... The lens is suspended behind the pupil and photoreceptive retinal cells cover the back of the eye. The pupil can be adjusted in ...
"Chemoreceptors in bacteria". Science 166 (3913): 1588-97. http://www.sciencemag.org/content/166/3913/1588.long ... பெருவிழுங்கி · புறத்தோல் உயிரணு போன்ற பெருவிழுங்கி (Epithelioid cell) · மாபெருஞ்செல் · குறுமணிப் புற்று. செயல்முறைகள். பழைய ...
The gustatory (taste) cells, which are chemoreceptors, occupy the central portion of the bud; they are spindle-shaped, and each ... The bud is formed by two kinds of cells: supporting cells and gustatory cells. ... Taste buds contain the taste receptor cells, which are also known as gustatory cells.[1] The taste receptors are located around ... These are located on top of the taste receptor cells that constitute the taste buds. The taste receptor cells send information ...
Indeed, the most sensitive mechanoreceptors in humans are the hair cells in the cochlea of the inner ear (no relation to the ... A mechanoreceptor, also called mechanoceptor, is a sensory cell that responds to mechanical pressure or distortion. There are ... Other mechanoreceptors than cutaneous ones include the hair cells, which are sensory receptors in the vestibular system of the ... Mechanoreceptors are also present in plant cells where they play an important role in normal growth, development and the ...
The cells are different with mitral having low firing-rates and being easily inhibited by neighboring cells, while tufted have ... 1: Olfactory bulb 2: Mitral cells 3: Bone 4: Nasal epithelium 5: Glomerulus 6: Olfactory receptor cells ... The main olfactory bulb transmits pulses to both mitral and tufted cells, which help determine odor concentration based on the ... Shepherd, G. M. "Neuronal Systems Controlling Mitral Cell Excitability." The Journal of Physiology. U.S. National Library of ...
Journal of Cell Biology. 1965, 27 (3): 505-17. PMC 2106769. PMID 5885427. doi:10.1083/jcb.27.3.505.. ... 中枢(英语:Central chemoreceptors). *外周(英语:Peripheral chemoreceptors) ... The effect of oxygen at high pressure on the histology of the central nervous system and sympathetic and endocrine cells. Acta ...
The fat cells take up glucose through special glucose transporters (GLUT4), whose numbers in the cell wall are increased as a ... The partial pressure of oxygen and carbon dioxide in the arterial blood is monitored by the peripheral chemoreceptors (PNS) in ... The sensors for the second are the parafollicular cells in the thyroid gland. The parathyroid chief cells secrete parathyroid ... Instead of measuring it directly in the blood flowing past the juxtaglomerular cells, these cells respond to the sodium ...
Presence in nonerythroid cells[edit]. Some nonerythroid cells (i.e., cells other than the red blood cell line) contain ... mesangial cells in the kidney, endometrial cells, cervical cells and vaginal epithelial cells.[11] In these tissues, ... Other cells that contain haemoglobin include the A9 dopaminergic neurons in the substantia nigra, macrophages, alveolar cells, ... Hemoglobin F (α2γ2) - In adults Hemoglobin F is restricted to a limited population of red cells called F-cells. However, the ...
Deonier CC, Richardson CH (1935). "The Tarsal Chemoreceptor Response of the Housefly, Musca Domestica L., to Sucrose and ... 96 Because the somatic tissue of the housefly consists of long-lived postmitotic cells, it can be used as an informative model ... enabling the chemoreceptors to taste afresh whatever they walk on next.[11] At the end of each leg is a pair of claws, and ... Houseflies have chemoreceptors, organs of taste, on the tarsi of their legs, so they can identify foods such as sugars by ...
The aorta consists of a heterogeneous mixture of smooth muscle, nerves, intimal cells, endothelial cells, fibroblast-like cells ... The aortic arch contains baroreceptors and chemoreceptors that relay information concerning blood pressure and blood pH and ... The smooth muscle of the great arteries and the population of cells that form the aorticopulmonary septum that separates the ...
Candidate chemoreceptor subfamilies differentially expressed in the chemosensory organs of the mollusc Aplysia. BMC Biology ... easily identified neurons with cell bodies up to 1 mm in size. Despite its seemingly simple nervous system, however, Aplysia ... a model for single cell, real-time and comparative genomics". National Human Genome Research Institute. online at http://www. ...
The soma (cell bodies) in these nuclei are the second-order neurons of the posterior column-medial lemniscus pathway, and their ... Respiration is regulated by groups of chemoreceptors. These sensors detect changes in the acidity of the blood; if, for example ...
Their retinas generally have both rod cells and cone cells (for scotopic and photopic vision), and most species have colour ... Many fish also have chemoreceptors that are responsible for extraordinary senses of taste and smell. Although they have ears, ... The gills actively uptake salt from the environment by the use of mitochondria-rich cells. Water will diffuse into the fish, so ... This is, however, often greatly reduced, consisting of a small mass of cells without any remaining gill-like structure. Marine ...
The lungs are made up of thirteen different kinds of cells, eleven types of epithelial cell and two types of mesenchymal cell.[ ... to nourish the cells. The red blood cells also carry carbon dioxide (CO2) away from the cells in the form of carboxyhemoglobin ... 11] The epithelial cells form the lining of the tracheal, and bronchial tubes, while the mesenchymal cells line the lungs. ... There are glands and mucus produced by goblet cells in parts, as well as smooth muscle, elastin or cartilage. Most of the ...
Cells. *Photoreceptor cells (Cone cell, Rod cell) → (Horizontal cell) → Bipolar cell → (Amacrine cell) → Retina ganglion cell ( ... Chemoreceptors[edit]. Main article: Chemoreceptor. Chemoreceptors, or chemosensors, detect certain chemical stimuli and ... Parasol cell, Bistratified cell, Giant retina ganglion cells, Photosensitive ganglion cell) → Diencephalon: P cell, M cell, K ... The two primary types of chemoreceptors are: *Distance chemoreceptors are integral to receiving stimuli as gases in the ...
"The Plant Cell. 12 (6): 949-961. doi:10.1105/tpc.12.6.949. ISSN 1532-298X. PMC 149095 . PMID 10852939.. ... Flower visitors such as insects and bats detect floral scent thanks to chemoreceptors of variable specificity to a specific VOC ... "The Plant Cell. 13 (10): 2333-2347. doi:10.1105/tpc.010162. ISSN 1532-298X. PMC 139162 . PMID 11595805.. ... "The Plant Cell. 15 (12): 2992-3006. doi:10.1105/tpc.016766. ISSN 1532-298X. PMC 282847 . PMID 14630969.. ...
... are detected by a suite of chemoreceptors innervated by the glossopharyngeal and vagus nerves. These chemoreceptors provide ... Sherwood, L. (2008). Human Physiology, From Cells to Systems. p. 327. ISBN 9780495391845. Retrieved 2013-03-10.. ... Pacemaker cells develop in the primitive atrium and the sinus venosus to form the sinoatrial node and the atrioventricular node ... Chemoreceptors Decreased levels of O2; increased levels of H+, CO2, and lactic acid ...
The olfactory receptor (OR) cells are neurons present in the olfactory epithelium, which is a small patch of tissue at the back ... There are millions of olfactory receptor neurons that act as sensory signaling cells. Each neuron has cilia in direct contact ...
Simple photoreceptor cells located at the genitals are important for this and other adult behaviours.[33] The male passes a ... A butterfly's sense of taste is coordinated by chemoreceptors on the tarsi, or feet, which work only on contact, and are used ... The surface of both butterflies and moths is covered by scales, each of which is an outgrowth from a single epidermal cell. The ... Most of the tissues and cells of the larva are broken down inside the pupa, as the constituent material is rebuilt into the ...
Via cranial and spinal nerves, the different types of sensory receptor cells (mechanoreceptors, photoreceptors, chemoreceptors ... Cell type[edit]. The cells that interpret information about the environment can be either (1) a neuron that has a free nerve ... The different types of functional receptor cell types are mechanoreceptors, photoreceptors, chemoreceptors (osmoreceptor), ... Receptor cells can be classified into types on the basis of three different criteria: cell type, position, and function. ...
... the production of red blood cells. This results in polycythemia, abnormally increased numbers of circulating red blood cells ... central chemoreceptors in the brain stem detect the acidity, and respond by increasing the respiratory rate; in OHS, this " ...
Another example of chemotropic movement includes the growth of individual neuronal cell axons in response to extracellular ... Chemoreceptor. *Mechanism. ReferencesEdit. *^ Reger, BJ; Chaubal, R; Pressey, R (1992). "Chemo-tropic responses by pearl millet ...
10). It consisting of the alveolar epithelial cells, their basement membranes and the endothelial cells of the alveolar ... This is detected by central blood gas chemoreceptors on the anterior surface of the medulla oblongata.[6] The aortic and ... The reaction is therefore catalyzed by carbonic anhydrase, an enzyme inside the red blood cells.[21] The reaction can go in ... Newstead James D (1967). "Fine structure of the respiratory lamellae of teleostean gills". Cell and Tissue Research. 79: 396- ...
In more complex animals, specialized receptor cells such as chemoreceptors and photoreceptors are found in groups and send ... The outer epithelial layer may include cells of several types including sensory cells, gland cells and stinging cells. There ... Unlike plant cells, animal cells have neither a cell wall nor chloroplasts. Vacuoles, when present, are more in number and much ... Keratinocytes make up to 95% of the cells in the skin.[16] The epithelial cells on the external surface of the body typically ...
In the case of skin cells, extra blood flow in them is used for thermoregulation of a body. In addition to delivering oxygen, ...
... and dendritic cells which present antigens to activate components of the adaptive immune system such as T-cells and B-cells.[51 ... The two types of cell are known as type I and type II alveolar cells[16] (also known as pneumocytes).[3] Types I and II make up ... Type I cells provide 95% of the surface area of each alveoli and are flat ("squamous"), and Type II cells generally cluster in ... There are two main types of primary tumour described as either small-cell or non-small-cell lung carcinomas. The major risk ...
Merkel cell nerve endings are found in the basal epidermis and hair follicles; they react to low vibrations (5-15 Hz) and deep ... Other types include mechanoreceptors, chemoreceptors, and nociceptors which send signals along a sensory nerve to the spinal ... In the case of touch and certain types of pain, the third neuron has its cell body in the VPN of the thalamus and ends in the ... The first neuron always has its cell body in the dorsal root ganglion of the spinal nerve (if sensation is in parts of the head ...
... which then bind to the chemoreceptors. "This transmits a signal to the inside of the cell saying that things are good," says ... "To do this, living cells are quickly frozen so that all the proteins are frozen in place-in the same places they were in the ... "One beauty of this is that weve shown that the receptors cluster in cells in the same way they did in the crystal structure," ... But if there are no good nutrients, the cell will do something called tumbling, in which it stops and randomly flips over in ...
In order for a cell to serve as a chemoreceptor cell, it must exhibit an apical process, extending to the luminal surface, as ... Thus, the nasal gustducin-ir cells are not brush cells. Nonetheless, the gustducin-ir cells we find do fall into the class of ... However, these are features common to many sensory cells, including taste cells and hair cells. Fujita (28) suggests that, ... chemoreceptor cells are likely to be remnants of the phylogenetically ancient population of solitary chemoreceptor cells found ...
... team led by researchers from Caltech has for the first time visualized and described the precise arrangement of chemoreceptors- ... Scientists get detailed glimpse of chemoreceptor architecture in bacterial cells. This side view of the bacterium Helicobacter ... Citation: Scientists get detailed glimpse of chemoreceptor architecture in bacterial cells (2009, September 24) retrieved 20 ... which then bind to the chemoreceptors. "This transmits a signal to the inside of the cell saying that things are good," says ...
Chemoreceptors are not confined to the cell poles in strains lacking both CheA and CheW. The chemoreceptor-CheW binary complex ... Polar location of the chemoreceptor complex in the Escherichia coli cell Message Subject. (Your Name) has forwarded a page to ... whereas the chemoreceptor-CheA binary complex is not confined to the cell poles in strains lacking CheW. The subcellular ... The eukaryotic cell exhibits compartmentalization of functions to various membrane-bound organelles and to specific domains ...
It discusses the interaction of chemoreceptors with downstream signaling elements, especially the interaction between ... It discusses the interaction of chemoreceptors with downstream signaling elements, especially the interaction between ... Citation: Wicher D (2012) Functional and evolutionary aspects of chemoreceptors. Front. Cell. Neurosci. 6:48. doi: 10.3389/ ... Bacterial Chemoreceptors. In Escherichia coli, chemoreceptors transmembrane methyl-accepting chemotaxis proteins (MCPs). They ...
"Chemoreceptor Cells" by people in this website by year, and whether "Chemoreceptor Cells" was a major or minor topic of these ... Cells specialized to detect chemical substances and relay that information centrally in the nervous system. Chemoreceptor cells ... "Chemoreceptor Cells" is a descriptor in the National Library of Medicines controlled vocabulary thesaurus, MeSH (Medical ... Below are the most recent publications written about "Chemoreceptor Cells" by people in Profiles. ...
"Chemoreceptor Cells" by people in this website by year, and whether "Chemoreceptor Cells" was a major or minor topic of these ... Cells specialized to detect chemical substances and relay that information centrally in the nervous system. Chemoreceptor cells ... "Chemoreceptor Cells" is a descriptor in the National Library of Medicines controlled vocabulary thesaurus, MeSH (Medical ... Chemosensory brush cells of the trachea. A stable population in a dynamic epithelium. Am J Respir Cell Mol Biol. 2013 Aug; 49(2 ...
... cells (Fig 4E right), another cell type derived from CB stem cells (Pardal et al, 2007). Hence, CB stem cells from TH‐VHLKO ... Number of BrdU+ cells versus total cells inside the area occupied by TH+ cells in the CB (VHLWT) or the CB‐SCG region (TH‐VHLKO ... Mazure NM, Pouysségur J (2010) Hypoxia‐induced autophagy: cell death or cell survival? Curr Opin Cell Biol 22: 177-180. ... cells (Fig 5D). Taken together, these data indicate that the lack of stem cell‐dependent glomus cell differentiation, observed ...
... on the chloride currents of isolated chemoreceptor cells of the rat carotid body was investigated using the whole-cell patch- ... 9. In summary, chemoreceptor cells express an inwardly rectifying Cl(-) current, which is directly regulated by pH(o). The ... in clusters of chemoreceptor cells in CO(2)/HCO3(-)-buffered media as measured with carboxy-SNARF-1. 8. When membrane potential ... changes were estimated in the cell-attached mode, 1 mM 9-AC hyperpolarized three out of five tested cells (by 14 mV in average ...
Deletion of the von Hippel-Lindau gene causes sympathoadrenal cell death and impairs chemoreceptor-mediated adaptation to ... Deletion of the von Hippel-Lindau gene causes sympathoadrenal cell death and impairs chemoreceptor-mediated adaptation to ... Vhl‐null animals had an increased number of adult CB stem cells, although the survival of newly generated neuron‐like glomus ... Vhl‐null animals had an increased number of adult CB stem cells, although the survival of newly generated neuron‐like glomus ...
What is neurosecretory cell? Meaning of neurosecretory cell medical term. What does neurosecretory cell mean? ... Looking for online definition of neurosecretory cell in the Medical Dictionary? neurosecretory cell explanation free. ... chalice cell. Goblet cell.. chemoreceptor cell. Chemoreceptor.. chief cell. 1. Any of the cells of the parathyroid gland that ... See also betz cells, gauchers cells, golgis cells, hela cells, hürthle cell, kupffers cells, merkel cell, mesangial cell, ...
... segmented cell explanation free. What is segmented cell? Meaning of segmented cell medical term. What does segmented cell mean? ... Looking for online definition of segmented cell in the Medical Dictionary? ... chalice cell. Goblet cell.. chemoreceptor cell. Chemoreceptor.. chief cell. 1. Any of the cells of the parathyroid gland that ... See: mitral cell. Türk irritation cell. See: Türk irritation cell. Tzanck cell. See: Tzanck cell. undifferentiated cell. A cell ...
Here we investigate the effects of hypoxia (down to 0.5% O2) on mitochondrial function in neonatal rat type-1 cells. The oxygen ... In summary, type-1 cell mitochondria display extraordinary oxygen sensitivity commensurate with a role in oxygen sensing. The ... The mechanism of oxygen sensing in arterial chemoreceptors is unknown but has often been linked to mitochondrial function. A ... Here we investigate the effects of hypoxia (down to 0.5% O2) on mitochondrial function in neonatal rat type-1 cells. The oxygen ...
These proteins are expressed in neurons tuned to lipid-derived pheromone ligands and surrounding cells10,11. Detection of non- ... Robertson, H. M. Molecular evolution of the major arthropod chemoreceptor gene families. Annu. Rev. Entomol. 64, 227-242 (2019 ... Gonzalez, F., Johny, J., Walker, W.B. et al. Antennal transcriptome sequencing and identification of candidate chemoreceptor ... Antennal transcriptome sequencing and identification of candidate chemoreceptor proteins from an invasive pest, the American ...
To explore the plasticity of these proteins, we have developed a simple method for selecting cells that swim to target ... Changing the specificity of a bacterial chemoreceptor J Mol Biol. 2006 Feb 3;355(5):923-32. doi: 10.1016/j.jmb.2005.11.025. ... To explore the plasticity of these proteins, we have developed a simple method for selecting cells that swim to target ... here provide a new approach for exploring the relationship between ligand binding and signal transduction by chemoreceptors and ...
Chemoreceptor areas and chemoreceptor reflexes Acta PhyslOl Scand 2254-65 Nell, E & ORegan, R G (l969a) Effects of smus and ... Control of penpheral chemoreceptors by efferent nerves In "PhYSIOlogy of the Penpheral Artenal Chemoreceptors ", HAcker & R G ... AdJusunent of chemoreceptor senSitIVIty III the cat caroud body by reciprocal synapses In "The Penpheral Artenal Chemoreceptors ... Different effects of putative neurotransmitters on cat and rabbit chemoreceptors In "Artenal Chemoreceptors", C Belmonte, D J ...
Cell 125: 143-160.. OpenUrlCrossRefPubMedWeb of Science. *↵. Hallem, E. A., A. Dahanukar and J. R. Carlson, 2006 Insect odor ... Chemoreceptors that have been lost at least once have high Ka/Ks:. Our final analysis of heterogeneity within the Or and Gr ... Specialist lineages are characterized by unusually high Ka/Ks at chemoreceptor loci:. McBride (2007) demonstrated that Or and ... We inferred the ratio of replacement to silent substitution (Ka/Ks) for each chemoreceptor gene present in the D. melanogaster ...
Unit Cell:. Length ( Å ). Angle ( ˚ ). a = 42.33. α = 90. b = 137.51. β = 94.46. ... Crystal structure of the sensory domain of the Campylobacter jejuni chemoreceptor Tlp3 (CcmL). *DOI: 10.2210/pdb4XMQ/pdb ... Structural basis for amino-acid recognition and transmembrane signalling by tandem Per-Arnt-Sim (tandem PAS) chemoreceptor ... the structural analysis suggests that the PTPSDs of amino-acid chemoreceptors are also likely to signal by a piston ...
Unit Cell:. Length ( Å ). Angle ( ˚ ). a = 24.6. α = 90. b = 99.4. β = 90.5. ... Crystal structure of the cytoplasmic domain of a bacterial chemoreceptor from Thermotoga maritima. *DOI: 10.2210/pdb2CH7/pdb ...
HCB339 (ΔMCP) cells expressing wild-type or mutant Tcp as the sole chemoreceptor were treated with 15% glycerol and then ... When 15% glycerol was added, cells expressing each mutant Tcp showed tumbling responses similar to those of cells expressing ... whereas a concentration of 1 mM is enough for that of cells expressing wild-type Tcp. HCB339 cells expressing Tcp-R63C or Tcp- ... HCB339 cells expressing any mutant Tcp receptor swarmed as fast as those expressing wild-type Tcp, suggesting that all of the ...
Chemoreceptor Cells / physiology*. Dogs. Glomerular Filtration Rate / physiology. Heart Rate. Kidney / physiology*. Muscles / ... 2. In ten dogs, with intact cervical vagosympathetic trunks, carotid chemoreceptor stimulation produced significant increases ... carotid chemoreceptor stimulation produced increases in AoP of 22.0 +/- 2.6% (n = 14, P , 0.001), in GFR of 36.9 +/- 4.2% (P , ... carotid chemoreceptor stimulation caused greater increase in AoP of 22.4 +/- 3.0% (n = 10, P , 0.001) and in MBF of 32.8 +/- ...
Cells respond to oxidants and electrophiles by activating receptor/transcription factor nuclear factor erythroid 2-related ... Cell-function; Cellular-function; Chemoreceptors; Chemotherapy; Treatment; Cellular-transport-mechanism; Cytochemistry; ... Cells respond to oxidants and electrophiles by activating receptor/transcription factor nuclear factor erythroid 2-related ... To corroborate the functions of cysteine residues, Nrf2 wild-type or mutants are expressed in Nrf2 knockout cells to ...
... a macrophage like cell line, primed with 50 to 1,000 picomolar (pM) iodine-125 tagged INFg or unprimed were incubated overnight ... Mammalian-cells; Chemoreceptors; Chemical-binding ... Mouse WEHI-3 cells, a macrophage like cell line, primed with 50 ... In cells treated with either compound at 100microM, the number of cells expressing I-A surface antigen was significantly ... concentrations in cells treated with 100microM AMV or vanadium-pentoxide were significantly greater than in control cells. ...
Research: Previously unknown aspect of cell internalization during embryonic development. Aug 15, 2019 ... Honey bee chemoreceptors found for smell and taste. Honey bees have a much better sense of smell than fruit flies or mosquitoes ... Wanner identified the family of honey bee chemoreceptors that deals with smell and taste. ... Citation: Honey bee chemoreceptors found for smell and taste (2006, October 25) retrieved 18 August 2019 from https://phys.org/ ...
Chemoreceptor Cells / drug effects*. Exercise / physiology*. Humans. Hyperoxia / physiopathology. Male. Oxygen Consumption / ... However, Acz administration did not completely attenuate the peripheral chemoreceptor response to hypoxia.. ... The peripheral chemoreceptor contribution to the ventilatory drive after acute Acz-induced carbonic anhydrase inhibition is not ...
... ... Chemical signals sensed on the periplasmic side of bacterial cells by transmembrane chemoreceptors are transmitted to the ... Chemoreceptor arrays comprise remarkably stable supramolecular structures in which thousands of chemoreceptors are networked ... Signalling-dependent interactions between the kinase-coupling protein CheW and chemoreceptors in living cells; Wiley Blackwell ...
Chemoreceptor Cells. *Chemoreceptor Cells: physiology. *Electrophysiology. *Gap Junctions. *Gap Junctions: physiology. * ... SC neurons were recorded using the blind whole cell patch-clamp technique and loading the soma with the pH-sensitive dye ...
Oxygen-sensitive K+ channels were first described in rabbit CB chemoreceptor cells, in which a transient outward K+ current was ... In voltage-clamp experiments, we found that, whereas adenoviral infections of chemoreceptor cells with Kv1.xDN did not modify ... Viral Gene Transfer of Dominant-Negative Kv4 Construct Suppresses an O2-Sensitive K+ Current in Chemoreceptor Cells. ... no attempts have been made to identify which Kv channel proteins are expressed in rabbit CB chemoreceptor cells and to ...
1973). The ultrastructure of chemoreceptor sensilla in Ciniflo (Araneida, Arachnida). Tissue Cell 5, 679-689. ... 1959). The chemoreceptors and other sense organs on the antennal flagellum of the grasshopper (Orthoptera; Acrididae). J. Morph ... This is not the case: Liphistius has the same ribbed spigots (chemoreceptors) on all extremities (Fig. 8A,B), but has no ... 1998). Preliminary electrophysiological study of the contact chemoreceptors in a spider. C. R. Acad. Sci. III 321, 463-469. ...
cell answers are found in the Tabers Medical Dictionary powered by Unbound Medicine. Available for iPhone, iPad, Android, and ... chemoreceptor cell. SEE: chemoceptor. chief cell. 1. Any of the cells of the parathyroid gland that secretes parathyroid ... blood cell. Any cell normally found circulating in the bloodstream. Blood cells include red cells and white cells. Red cells ... null cell. 1. A large lymphocyte without the cell markers of either a T cell or a B cell. Natural killer cells are examples of ...
  • PASADENA, Calif.-Using state-of-the-art electron microscopy techniques, a team led by researchers from the California Institute of Technology (Caltech) has for the first time visualized and described the precise arrangement of chemoreceptors-the receptors that sense and respond to chemical stimuli-in bacteria. (caltech.edu)
  • To fully understand just what is happening in these cells, Jensen says, it is thus important to figure out the ways in which these receptors interact with one another, which in turn depends on understanding precisely how they are situated in relation to one another. (caltech.edu)
  • These chemosensory cells express T2R "bitter-taste" receptors and α-gustducin, a G protein involved in chemosensory transduction. (pnas.org)
  • At each of the vertices sit six chemoreceptors, arranged in what scientists call "trimers of dimers," which means there are three sets of two paired receptors in each grouping. (phys.org)
  • There are two major types of chemoreceptors, ionotropic and metabotropic receptors. (frontiersin.org)
  • While most chemoreceptors in mammals are metabotropic receptors, chemoreception in insects is ionotropic. (frontiersin.org)
  • This formula is valid for a single receptor as well as for a receptor array such as a cell surface equipped with receptors ( Bialek and Setayeshgar, 2005 ). (frontiersin.org)
  • Expression of Bitter Taste Receptors and Solitary Chemosensory Cell Markers in the Human Sinonasal Cavity. (ucdenver.edu)
  • Expression of taste receptors in solitary chemosensory cells of rodent airways. (ucdenver.edu)
  • These receptors are also seven-transmembrane domain proteins and, together with the ORs, form the large chemoreceptor superfamily 12 . (nature.com)
  • The new tar alleles and the techniques described here provide a new approach for exploring the relationship between ligand binding and signal transduction by chemoreceptors and for engineering new receptors for applications in biotechnology. (nih.gov)
  • This signal may be in the form of an action potential, if the chemoreceptor is a neuron, or in the form of a neurotransmitter that can activate a nerve fiber if the chemoreceptor is a specialized cell, such as taste receptors, or an internal peripheral chemoreceptor, such as the carotid bodies. (wikipedia.org)
  • Plant hormone receptors can either be integrated in plant cells or situate outside the cell, in order to facilitate chemical structure and composition. (wikipedia.org)
  • Examples of direct chemoreceptors include: Taste receptors in the gustatory system: The primary use of gustation as a type of chemoreception is for the detection of tasteants. (wikipedia.org)
  • Mouse WEHI-3 cells, a macrophage like cell line, primed with 50 to 1,000 picomolar (pM) iodine-125 tagged INFg or unprimed were incubated overnight with 0 or 100 nanomolar (nM) or 100 micromolar (microM) ammonium-metavanadate (7803556) (AMV) or vanadium-pentoxide (1314621) at 22 degrees-C. The effects on INFg binding to cellular receptors were determined. (cdc.gov)
  • The abilities to see, to hear, to smell, and to taste are all possible because of sensory receptors, or special nerve cells or endings of the peripheral nervous system (part of the nervous system consisting mainly of nerves that extend from the brain and spinal cord to areas in the rest of the body). (encyclopedia.com)
  • The receptors for the senses of smell and taste are chemoreceptors that are sensitive to various chemicals. (encyclopedia.com)
  • A special area of the brain called the chemoreceptor trigger zone receives input from those receptors which are sensitive to chemicals which can be dangerous. (wisegeek.org)
  • Something interesting I read about chemoreceptors recently, is that if you eat too much of certain foods, like, say garlic, you end up overwhelming the receptors in your nose and your mouth so that they can't taste it anymore. (wisegeek.org)
  • It goes and attaches to the chemoreceptors in your brain where that chemical is supposed to go, so even if you feel tired and want to sleep, you can't, because the receptors have already been taken over. (wisegeek.org)
  • Chemoreceptors are found in four primary locations: the lateral and medial flagella antennules ('smell' receptors), and the walking legs and axilla beds ('taste' receptors). (bio.net)
  • In the upper respiratory epithelium, bitter and sweet taste receptors present in solitary chemosensory cells influence antimicrobial innate immune defense responses. (sciencemag.org)
  • Whereas activation of bitter taste receptors (T2Rs) stimulates surrounding epithelial cells to release antimicrobial peptides, activation of the sweet taste receptor (T1R) in the same cells inhibits this response. (sciencemag.org)
  • Excitatory nicotinic receptors are present on peripheral chemoreceptor cells. (ahajournals.org)
  • 16,17 Nicotine could increase chemoreceptor activity through excitatory nicotinic receptors present on the glomus cells. (ahajournals.org)
  • 24-26 This is likely because of the fact that the effects of exogenous nicotine on chemoreceptors depend on the predominance of nicotinic and muscarinic receptors on the carotid bodies. (ahajournals.org)
  • Besides α-cells of the pancreas, systemic low-glucose receptors have been proposed to exist at the portal vein ( 7 ) and in the carotid body (CB) ( 8 - 11 ). (diabetesjournals.org)
  • Here we show that brush cells of the mouse trachea express the receptors (Tas2R105, Tas2R108), the downstream signaling molecules (-gustducin, phospholipase C2) of bitter taste transduction, the synthesis and packaging machinery for acetylcholine, and are addressed by vagal sensory nerve fibers carrying nicotinic acetylcholine receptors. (fraunhofer.de)
  • they probably function as chemoreceptors ( i.e., smell and taste receptors). (britannica.com)
  • The HMS researchers already knew that cells in the olfactory necklace have receptors that detect carbon dioxide, a naturally aversive stimulus for the mouse. (eurekalert.org)
  • The scientists searched for necklace olfactory receptors using genetic screens that identified molecules that could be chemoreceptors. (eurekalert.org)
  • Without that hook, which had been used to uncover all currently known mammalian odorant receptors, they instead looked for proteins that spanned the membrane, reaching out of the cell to detect odors and into the cell to communicate a message that would serve as a signal to the brain. (eurekalert.org)
  • The carotid body arterial chemoreceptors constitute unique sensory receptors capable of rapidly monitoring the levels of arterial blood oxygen and carbon dioxide. (environmental-expert.com)
  • Like other receptors, Tsr spans the cell membrane, communicating to proteins inside the cell in order to respond to threats or opportunities in the environment. (redorbit.com)
  • Phenylalanine pairs capable of forming a molecular switch are also present in many other signaling proteins, including receptors in human cells, making it an attractive target for drug design and biotechnology applications. (redorbit.com)
  • In bacterial chemotaxis, chemosensory sensitivity is typically brought about by changes in the methylation status of chemotaxis receptors capable of modulating the ability of motile cells to navigate in gradients of various physicochemical cues. (asm.org)
  • More than 1300 potential chemoreceptor genes have been identified in C. elegans, which are generally prefixed sr for serpentine receptor. (wikipedia.org)
  • Here, we investigate patterns of gene loss/gain, divergence, and polymorphism in the entire repertoire of ∼130 chemoreceptor genes from five closely related species of Drosophila that share a common ancestor within the past 12 million years. (genetics.org)
  • Cells respond to oxidants and electrophiles by activating receptor/transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) to coordinate the induction of cytoprotective genes critical for defense against oxidative and other stresses. (cdc.gov)
  • Although progress has been made to characterize this current with electrophysiological and pharmacological tools, no attempts have been made to identify which Kv channel proteins are expressed in rabbit CB chemoreceptor cells and to determine + with adenoviruses that enabled ecdysone-inducible expression of the dominant-negative constructs and reporter genes in poly- cistronic vectors. (uva.es)
  • These genes are unusually clustered on chromosomes, both within and between families, and are enigmatically concentrated on the large chromosome V. Comparative studies with C. briggsae have revealed extraordinary divergence of the chemoreceptor repertoire between the two species, including frequent amplifications of subfamilies in C. elegans and positive selection in the srz family. (nih.gov)
  • In addition, they speculated that necklace chemoreceptors would be encoded by genes that evolved quickly. (eurekalert.org)
  • The morphometric changes in the ZP could be explained by the activation of the mechanoreceptor Integrina / Pax-Fax, located in the chondrocytes, which through mechanical stimulation generates activation of the pathway PI3k / Akt, inhibiting the phosphorylation of B-Catenin, which on accumulation migrate to the nucleus promoting cell proliferation and MEC secretion genes (Takeuchi et al. (thefreedictionary.com)
  • Dynamic changes in the expression of chemoreceptor genes may underlie some of these food and state-dependent changes in chemosensory behavior, but the mechanisms underlying these expression changes are unknown. (sigmaaldrich.com)
  • NPR-1-mediated regulation of srh-234 is dependent on gap-junctions, implying that circuit inputs regulate the expression of chemoreceptor genes in sensory neurons. (sigmaaldrich.com)
  • Together, our results suggest that sensory- and circuit-mediated regulation of chemoreceptor genes via multiple pathways may allow animals to precisely regulate and fine-tune their chemosensory responses as a function of internal and external conditions. (sigmaaldrich.com)
  • Here we investigate the effects of hypoxia (down to 0.5% O2) on mitochondrial function in neonatal rat type-1 cells. (nihr.ac.uk)
  • In physiology, a chemoreceptor detects changes in the normal environment, such as an increase in blood levels of carbon dioxide (hypercapnia) or a decrease in blood levels of oxygen (hypoxia), and transmits that information to the central nervous system which engages body responses to restore homeostasis. (wikipedia.org)
  • However, Acz administration did not completely attenuate the peripheral chemoreceptor response to hypoxia. (biomedsearch.com)
  • Increased activity of chemoreceptors caused by hypoxia or an increase in the partial pressure of carbon dioxide augments both the rate and depth of breathing, which restores partial pressures of oxygen and carbon dioxide to their usual levels. (britannica.com)
  • Hypoxia , or the reduction of oxygen supply to tissues to below physiological levels (produced, for example, by a trip to high altitudes), stimulates the carotid and aortic bodies, the principal arterial chemoreceptors. (britannica.com)
  • It is thought that hypoxia and hypercapnia (excessive carbon dioxide in the blood) cause the release of one or more of these neuroactive substances from the type I cells, which then act on the sensory nerve. (britannica.com)
  • Hypoxia initiates the neurosecretory response of the carotid body (CB) by inhibiting one or more potassium channels in the chemoreceptor cells. (uva.es)
  • Oxygen-sensitive K+ channels were first described in rabbit CB chemoreceptor cells, in which a transient outward K+ current was reported to be reversibly inhibited by hypoxia. (uva.es)
  • In voltage-clamp experiments, we found that, whereas adenoviral infections of chemoreceptor cells with Kv1.xDN did not modify the O -sensitive K+ current, infections with Kv4.xDN suppressed the transient outward current in a time-dependent manner, significantly depolarized the cells, and abolished the depolarization induced by hypoxia. (uva.es)
  • 5-HT did not change intracellular Ca2+ [Ca2+]i in chemoreceptor cells, whereas induced repetitive [Ca2+]i increases during hypoxia. (nii.ac.jp)
  • Chemoreceptors located in the carotid and aortic bodies increase ventilation (Ve), blood pressure (BP), heart rate (HR), and sympathetic nerve activity to muscle circulation (MSNA) in response to hypoxia. (ahajournals.org)
  • We tested the hypothesis that nicotine replacement therapy (NRT) increases MSNA and chemoreceptor sensitivity to hypoxia. (ahajournals.org)
  • Some, but not all, 21-23 animal studies have been able to show that nicotine increases peripheral chemoreceptor sensitivity to hypoxia. (ahajournals.org)
  • Rotenone, a drug that occludes glomus cell sensitivity to hypoxia, did not abolish responsiveness to low glucose. (diabetesjournals.org)
  • The CB, the main O 2 -sensing peripheral arterial chemoreceptor in mammals, is composed of innervated clusters of glomus cells that, when activated by hypoxia, release transmitters, which either have predominantly an autocrine effect (dopamine) or stimulate afferent sensory fibers (ATP) ( 11 - 13 ). (diabetesjournals.org)
  • There are two kinds of respiratory chemoreceptors: arterial chemoreceptors, which monitor and respond to changes in the partial pressure of oxygen and carbon dioxide in the arterial blood, and central chemoreceptors in the brain, which respond to changes in the partial pressure of carbon dioxide in their immediate environment. (britannica.com)
  • Emphasis will be placed on the control of sympathetic outflow by central chemoreceptors. (scielo.br)
  • However, since the level of activity of the retrotrapezoid nucleus is regulated by converging inputs from wake-promoting systems, behavior-specific inputs from higher centers and by chemical drive, the main focus of the present manuscript is to review the contribution of central chemoreceptors to the control of autonomic and respiratory mechanisms. (scielo.br)
  • Several lines of evidence suggest that brain P CO2 is detected via changes in extracellular fluid pH, but the molecular and network basis of central chemoreceptors is still poorly understood (3). (scielo.br)
  • Does each of the regions responsive to acidification contain central chemoreceptors involved in cardiorespiratory control? (scielo.br)
  • And these cells are called the central chemoreceptors. (khanacademy.org)
  • They're right in the same neighborhood, and so these central chemoreceptors don't have to go too far to communicate their information. (khanacademy.org)
  • So if you have central chemoreceptors you also probably can expect that there would be some peripheral chemoreceptors, and these ones are also very important. (khanacademy.org)
  • So that's information coming to the respiratory center from our peripheral and central chemoreceptors then is mostly about chemicals. (khanacademy.org)
  • It is also an important source of information for researchers and clinicians in the fields of hypoxic pulmonary vasoconstriction and pulmonary hypertension as well as for researchers in the field of erythropoietin and central chemoreceptors. (environmental-expert.com)
  • The present book represents an updated review of the physiology of the carotid body chemoreceptors. (environmental-expert.com)
  • For example, rods and cones respond to visual stimuli, hair cells transduce auditory stimuli, taste receptor cells mediate perception of salt, sweet, sour and bitter, while olfactory receptor neurons detect the variety of odorants that fill our environment. (pnas.org)
  • amacrine cell any of five types of retinal neurons that seem to lack large axons, having only processes that resemble dendrites. (thefreedictionary.com)
  • citation needed] Examples of distance chemoreceptors are: olfactory receptor neurons in the olfactory system: Olfaction involves the ability to detect chemicals in the gaseous state. (wikipedia.org)
  • Volatile chemical stimuli enter the nose and eventually reach the olfactory epithelium which houses the chemoreceptor cells known as olfactory sensory neurons often referred to as OSNs. (wikipedia.org)
  • SC neurons were recorded using the blind whole cell patch-clamp technique and loading the soma with the pH-sensitive dye pyranine through the patch pipette. (mendeley.com)
  • Like other neurons, these cells are usually designed with customized locks which only fit the keys of specific chemicals, which makes them sensitive only to certain types of chemicals or chemical families. (wisegeek.org)
  • High levels of CO 2 exert an excitatory effect on sympathetic outflow that is mediated by specialized chemoreceptors such as the neurons located in the retrotrapezoid region. (scielo.br)
  • How do non neural cells communicate with sensory neurons? (brainscape.com)
  • Many of the energetic costs within neurons are linked to 3Na + /2K + ATPase activity, which consumes energy to pump Na + and K + ions across the cell membrane and is essential for the maintenance of the resting potential and its restoration following signalling. (biologists.org)
  • In the case of the very simplest organisms, the entire machinery for sensing the environment and acting upon it is found within the same cell, whereas at their most elaborate, for example the mammalian visual system, peripheral sensory structures may consist of millions of neurons, with even greater numbers of neurons involved in processing the information they obtain within the central nervous system. (biologists.org)
  • Testing these ideas requires determining, point-to-point, how tastes are initially represented within the population of receptor cells and how this representation is transformed as it moves to higher-order neurons. (jneurosci.org)
  • This is partly because taste receptor cells in the vertebrate tongue and soft palate transmit their activity to both afferent neurons and other taste cells through complex pathways that may interact and that do not use synapses ( Chaudhari and Roper, 2010 ). (jneurosci.org)
  • where D is the diffusion coefficient of the chemoattractant, r the receptor radius (e.g., cell radius), c m the mean concentration and t the detection time ( Berg and Purcell, 1977 ). (frontiersin.org)
  • To determine a molecule with a diffusion coefficient of 10 −5 cm 2 /s at a mean concentration of 1 μM with an accuracy of 1%, a cell with a radius of 1 μm requires a measuring time of 10 ms. For a single receptor with a radius of 1 nm a detection time of 17 s would be required. (frontiersin.org)
  • External molecules bind to chemoreceptors located in the plasma membrane, the subsequent receptor activation transduces the external signal across the plasma membrane. (frontiersin.org)
  • Solitary chemosensory cells and bitter taste receptor signaling in human sinonasal mucosa. (ucdenver.edu)
  • The insect chemoreceptor superfamily comprises the olfactory receptor ( Or ) and gustatory receptor ( Gr ) multigene families. (genetics.org)
  • Although the fold and mode of ligand binding of the PTPSD are different from the aspartic acid receptor Tar, the structural analysis suggests that the PTPSDs of amino-acid chemoreceptors are also likely to signal by a piston displacement mechanism. (rcsb.org)
  • A chemoreceptor, also known as chemosensor, is a specialized sensory receptor cell which transduces a chemical substance (endogenous or induced) to generate a biological signal. (wikipedia.org)
  • There are 5 major categories of hormones that are unique to plants which once bound to the receptor, will trigger a response in target cells. (wikipedia.org)
  • While all three types of cells are integral to normal function of the epithelium, only OSN serve as receptor cells, i.e. responding to the chemicals and generating an action potential that travels down the olfactory nerve to reach the brain. (wikipedia.org)
  • To explore the conformational changes that occur within this protein assembly during signalling, we used in vivo cross-linking methods to detect close interactions between the coupling protein CheW and the serine receptor Tsr in intact Escherichia coli cells. (uchile.cl)
  • This work provides further insight into receptor structure-function relationships and will be helpful to annotate chemoreceptors of other bacteria. (asm.org)
  • This DNA contained an open reading frame for a 577-amino-acid protein showing several characteristics of the bacterial chemoreceptors and, therefore, we named this gene lcrI for Leptospirillum chemotaxis receptor I. This is the first sequence reported for a gene from L. ferrooxidans encoding a protein. (asm.org)
  • The antennules have fine hairs of two types: aesthetase hairs, with receptor sensilla on them, and guard cells. (bio.net)
  • In the legs, receptor cells tended to be slower responding and slower recovering than in antennule cells, which recover quickly and therefore respond to quick pulses. (bio.net)
  • Is there other information, more rapidly obtainable than average concentration amplitude, which might be measured by receptor cells? (bio.net)
  • Stimulation of the sweet taste receptor (T1R) in solitary chemosensory cells of the upper respiratory epithelium inhibits the release of antimicrobial peptides by neighboring epithelial cells. (sciencemag.org)
  • In patch-clamped glomus cells, exposure to low glucose resulted in inhibition of macroscopic outward K + currents and in the generation of a depolarizing receptor potential (DRP). (diabetesjournals.org)
  • Supported by National Institutes of Health grants, researchers at Oak Ridge National Laboratory (ORNL), the University of Tennessee (UT), and the UT-ORNL Joint Institute for Computational Sciences (JICS) discovered a molecular "switch" in a receptor that controls cell behavior using detailed molecular dynamics simulations on a computer called Anton built by D. E. Shaw Research in New York City. (redorbit.com)
  • The team led by Baudry and Igor Zhulin, distinguished research and development staff member in the ORNL Computer Science and Mathematics Division, joint professor in the UT Department of Microbiology, and JICS joint faculty member determined that a single pair of phenylalanine amino acids called Phe396 located at the chemoreceptor tip was acting as a receptor switch. (redorbit.com)
  • Oxygen sensitivity of mitochondrial function in rat arterial chemoreceptor cells. (nihr.ac.uk)
  • The mechanism of oxygen sensing in arterial chemoreceptors is unknown but has often been linked to mitochondrial function. (nihr.ac.uk)
  • 1. In chloralose-anaesthetized and artificially ventilated dogs, the carotid sinus regions were vascularly isolated and perfused either with arterial or mixed (arterial and venous) blood (partial pressure of O2 (PO2) 43.8 +/- 2.4 mmHg, mean +/- S.E.M. n = 14) to stimulate the carotid chemoreceptors. (biomedsearch.com)
  • One key example is that an increase in CNS arterial partial pressure of carbon dioxide (P CO2 ) (henceforth called central chemoreceptor stimulation) increases breathing and sympathetic nerve activity (SNA) (1,2). (scielo.br)
  • Arterial Chemoreceptors should be considered as a prime source of information and as a guideline to every researcher in the field of arterial chemoreception in the years to come. (environmental-expert.com)
  • No comments were found for Arterial Chemoreceptors . (environmental-expert.com)
  • Arterial chemoreceptors : new directions and translational perspectives / Estelle B. Gauda, Maria Emilia Monteiro, Nanduri Prabhakar, Christopher Wyatt, Harold D. Schultz, editors. (bl.uk)
  • In humans, lymphocytes are small cells (~6 µm in diameter), columnar epithelial cells (10 µm x 20 µm) are medium-size cells, and mature ova (120-150 µm) are some of the largest cells. (thefreedictionary.com)
  • 1. In the lung, either of two types of epithelial cells lining the alveoli. (thefreedictionary.com)
  • Type I cells are simple thin squamous epithelial cells. (thefreedictionary.com)
  • 2. In the mammary glands, the milk-secreting epithelial cells, which are activated during lactation. (thefreedictionary.com)
  • In humans, lymphocytes are small cells (6 µm in diameter), columnar epithelial cells (10 µm x 20 µm) are medium-size cells, and mature ova (120 to 150 µm) are some of the largest cells. (tabers.com)
  • Outermost layer of connective tissue and layer of squamous epithelial cells. (studystack.com)
  • Homeostasis of the mucous layer of intestinal epithelial cells (IECs) in the mammalian GI tract is regulated by a variety of signals including cellular polyamines and hormonal signals [ 8 , 9 , 10 ]. (nature.com)
  • A model of the hexagonal arrangement of the chemoreceptors and their groupings in what are known as "trimers of dimers. (caltech.edu)
  • Through analysis of multiple mutants, we conclude that curvature sensitivity is intrinsic to chemoreceptor trimers-of-dimers, and results from conformational entropy within the trimer-of-dimers geometry. (stanford.edu)
  • These cells are also sometimes known as chemosensors, because they behave like sensors which "sniff" for specific chemicals of interest. (wisegeek.org)
  • When people taste food, it is because these cells respond to the chemicals in the food, sending a signal to the brain to let the brain know about what's happening in the mouth. (wisegeek.org)
  • This explains why foods can taste different as they are chewed and swallowed, and also why some foods have an aftertaste , as certain chemicals can take longer to stimulate the chemoreceptors. (wisegeek.org)
  • The carotid body explains why people cannot suffocate themselves by holding their breath, because these cells will eventually trigger an involuntary breathing response due to the critical levels of chemicals they detect in the blood. (wisegeek.org)
  • Chemoreceptors can also be found in the brain itself, monitoring pH level and alerting the brain to the presence of chemicals which could indicate a problem. (wisegeek.org)
  • When these cells send a message to the brain that those chemicals have been ingested, the brain triggers a vomiting reflex so that the chemicals will be voided from the body before they can be metabolized. (wisegeek.org)
  • When the researchers landed likely chemoreceptor candidates, they tested them to see if they could detect a variety of chemicals. (eurekalert.org)
  • This means that it does not have sensory nerve cells that are activated by chemicals, but only pressure-sensitive nerve endings, that stimulate reflex mechanisms that allow the body to adapt to changes in blood pressure by dilating or constricting the blood vessels. (medirabbit.com)
  • The spatial distribution of the membrane chemoreceptors and associated cytoplasmic chemotaxis proteins in Escherichia coli were examined as a prototypic functional aggregate in bacterial cells. (sciencemag.org)
  • The transduction of the chemotaxis signal is initiated by a chemoreceptor-CheW-CheA ternary complex at the inner membrane. (sciencemag.org)
  • The subcellular localization of the chemotaxis proteins may reflect a general mechanism by which the bacterial cell sequesters different regions of the cell for specialized functions. (sciencemag.org)
  • Aspects of innate immunity derive from characteristics inherent to phagocytes, including chemotaxis toward and engulfment of unicellular organisms or cell debris. (elifesciences.org)
  • Chemoreceptors are at the beginnings of chemosensory signaling cascades that mediate chemotaxis. (asm.org)
  • Since pseudomonads show chemotaxis to many different compounds and possess different types of chemoreceptors, they are model organisms to establish relationships between chemoreceptor structure and function. (asm.org)
  • Deletion of the mcpP gene resulted in a dramatic reduction in chemotaxis toward these ligands, and complementation restored a native-like phenotype, indicating that McpP is the major chemoreceptor for these compounds. (asm.org)
  • Nearly all motile bacteria can sense and respond to their surroundings-finding food, avoiding poisons, and targeting cells to infect, for example-through a process called chemotaxis. (caltech.edu)
  • Bacterial chemotaxis guides motile cells in gradients of attractants and repellents over broad concentration ranges, thus allowing bacteria to quickly adapt to changes in their surroundings. (asm.org)
  • We find, in both rats and mice, an extensive population of chemosensory cells that reach the surface of the nasal epithelium and form synaptic contacts with trigeminal afferent nerve fibers. (pnas.org)
  • By extending to the surface of the nasal epithelium, these chemosensory cells serve to expand the repertoire of compounds that can activate trigeminal protective reflexes. (pnas.org)
  • The presence of specialized epithelial chemosensory cells would provide a transduction system for detection of lipophobic stimuli, but such cells have yet to be demonstrated in the nasal cavity of any mammal. (pnas.org)
  • We report here that, in addition to free nerve endings, an extensive population of trigeminal chemosensory cells exists within the nasal respiratory epithelium, providing an avenue whereby inhaled toxic dusts or aerosols can trigger respiratory reflexes. (pnas.org)
  • Saunders CJ, Christensen M, Finger TE, Tizzano M. Cholinergic neurotransmission links solitary chemosensory cells to nasal inflammation. (ucdenver.edu)
  • Chemosensory brush cells of the trachea. (ucdenver.edu)
  • The specificity of a chemotactic response is determined by the chemoreceptor that is at the beginning of the chemosensory signaling cascade. (asm.org)
  • Morphologically similar cells in the nose have been identified as solitary chemosensory cells responding to taste stimuli and triggering trigeminal reflexes. (fraunhofer.de)
  • Here, we identify PP2861 (termed McpP) of Pseudomonas putida KT2440 as a chemoreceptor with a novel ligand profile. (asm.org)
  • To advance the understanding of this family, we have used the PcaY_PP (PP2643) chemoreceptor of Pseudomonas putida KT2440 as a model. (frontiersin.org)
  • Tumors in chemoreceptor tissue usually develop principally in either the aortic body (found in the chest) or in the carotid bodies (found in the neck). (merckvetmanual.com)
  • The aortic nerve has no chemoreceptors, but only baroreceptors. (medirabbit.com)
  • An example of direct chemoreceptors are the cells located on the tongue. (wisegeek.org)
  • Direct chemoreceptors are also found in the carotid body , a structure located at the branch of the carotid artery. (wisegeek.org)
  • A1K5G6_AZOSB Putative citrate chemoreceptor protein OS=Azoarcus sp. (uniprot.org)
  • Windchime - Something to consider is that often people will have more or less chemoreceptors on their tongue (as well as olfactory chemoreceptors). (wisegeek.org)
  • What they saw when they glimpsed the insides of these quick-frozen bacteria were chemoreceptors arranged in a regular, repeating lattice of hexagons-a structure with six sides and six corners or vertices-that are 12 nanometers apart, center to center. (caltech.edu)
  • Motile bacteria sense their physical and chemical environment through highly cooperative, ordered arrays of chemoreceptors. (nih.gov)
  • Bacteria have evolved a wide range of chemoreceptors with different ligand specificities. (frontiersin.org)
  • In bacteria, the sensing process begins with chemoreceptors-proteins that extend, like tiny antennae, from the cell body to the exterior of the cell. (caltech.edu)
  • Using advanced electron microscopy techniques and new crystallography results, Jensen and Briegel, working with researchers from Cornell University, have built the first model that depicts precisely how chemoreceptors and the proteins around them are structured at the sensing tip of bacteria. (caltech.edu)
  • What is the bacteria cell wall made of? (flashcardmachine.com)
  • It's like a protein antenna that protrudes from the bacterial cell body, through the membrane, and out onto the surface," says Jensen. (caltech.edu)
  • The eukaryotic cell exhibits compartmentalization of functions to various membrane-bound organelles and to specific domains within each membrane. (sciencemag.org)
  • Polar localization of the cytoplasmic CheA and CheW proteins is dependent on membrane-bound chemoreceptor. (sciencemag.org)
  • 8. When membrane potential changes were estimated in the cell-attached mode, 1 mM 9-AC hyperpolarized three out of five tested cells (by 14 mV in average) incubated in CO(2)/HCO3(-)-buffered media. (ox.ac.uk)
  • 1. any of the protoplasmic masses making up organized tissue, consisting of a nucleus surrounded by cytoplasm enclosed in a cell or plasma membrane. (thefreedictionary.com)
  • A cell is a group of self-sustaining biochemical reactions that are isolated from the environment by a selectively permeable lipid membrane. (thefreedictionary.com)
  • It is concluded that H(2)S excites type 1 cells through the inhibition of background (TASK) potassium channels leading to membrane depolarisation and voltage-gated Ca(2+) entry. (ox.ac.uk)
  • RESEARCH DESIGN/METHODS AND RESULTS- Removal of extracellular glucose elicited a cell secretory response, abolished by blockade of plasma membrane Ca 2+ channels, and a reversible increase in cytosolic Ca 2+ concentration. (diabetesjournals.org)
  • As their name indicates, these chemoreceptors span a cell membrane seven times. (eurekalert.org)
  • Here, we quantify the curvature-dependent localization of chemoreceptors in live cells by artificially deforming growing cells of Escherichia coli in curved agar microchambers, and find that chemoreceptor cluster localization is highly sensitive to membrane curvature. (stanford.edu)
  • A substantial proportion of neuronal energy consumption is related to the movements of ions across the neuronal cell membrane through ion channels, though other processes such as vesicle loading and transmitter recycling also consume energy. (biologists.org)
  • Enter the chemoreceptors, tiny protein molecules found at the front of the bacterium, near the flagella. (caltech.edu)
  • which corresponds to only a few molecules per cell volume. (frontiersin.org)
  • Other key reactions move molecules and molecular complexes within the cell, sometimes changing the cell's shape. (thefreedictionary.com)
  • However, using Anton, researchers were able to simulate only a small part of the chemoreceptor containing the Phe396 pair known as a dimer, meaning two identical molecules. (redorbit.com)
  • The present results suggested that the signal transduction from CB is regulated by noradrenaline in chemoreceptor cells under hypertensive conditions. (nii.ac.jp)
  • In animal cells, a signal transduction pathway might include 500 proteins. (caltech.edu)
  • The team, including collaborators at the University of Utah led by John Parkinson, compared thousands of chemoreceptor sequences from all microbial genomes in the Microbial Signal Transduction database available as of August 2012. (redorbit.com)
  • Primary effects of carotid chemoreceptor stimulation on gracilis muscle and renal blood flow and renal function in dogs. (biomedsearch.com)
  • More recently, focal acidification of several other brainstem regions in vivo (nucleus of the solitary tract (NTS), retrotrapezoid nucleus (RTN), raphe, pre-Bötzinger complex, locus coeruleus (LC), hypothalamus) has also been found to activate breathing and sympathetic outflow and this evidence has led to the view that central chemoreceptor stimulation is a 'distributed' property (3). (scielo.br)
  • In this short review, we consider a modern view about the brain areas involved in cardiorespiratory control elicited by central chemoreceptor stimulation. (scielo.br)
  • blocks chemoreceptor trigger zone, diminishes vestibular stimulation, and depresses labyrinthine function through its central anticholinergic activity. (drugs.com)
  • Vhl ‐null animals had an increased number of adult CB stem cells, although the survival of newly generated neuron‐like glomus cells was severely compromised. (embopress.org)
  • basket cell a neuron of the cerebral cortex whose fibers form a basket-like nest in which a Purkinje cell rests. (thefreedictionary.com)
  • A somatic motor neuron that has its cell body in the ventral (anterior) horn of the gray matter of the spinal cord. (tabers.com)
  • Here, we identified a KIN-29 (SIK)-dependent chemoreceptor, srh-234, in C. elegans whose expression in the ADL sensory neuron type is regulated by integration of sensory and internal feeding state signals. (sigmaaldrich.com)
  • While swimming in a single direction, a bacterium such as Escherichia coli may encounter some nutrients, which then bind to the chemoreceptors. (caltech.edu)
  • The mobility of two kinase domains in the Escherichia coli chemoreceptor array varies with signalling state. (nih.gov)
  • Chemoreceptors are not confined to the cell poles in strains lacking both CheA and CheW. (sciencemag.org)
  • The chemoreceptor-CheW binary complex is polarly localized in the absence of CheA, whereas the chemoreceptor-CheA binary complex is not confined to the cell poles in strains lacking CheW. (sciencemag.org)
  • Chemical signals sensed on the periplasmic side of bacterial cells by transmembrane chemoreceptors are transmitted to the flagellar motors via the histidine kinase CheA, which controls the phosphorylation level of the effector protein CheY. (uchile.cl)
  • Chemoreceptor arrays comprise remarkably stable supramolecular structures in which thousands of chemoreceptors are networked through interactions between their cytoplasmic tips, CheA, and the small coupling protein CheW. (uchile.cl)
  • Ligand recognition at the LBD generates a molecular stimulus that is transmitted to the other extension of the chemoreceptor, where it modulates CheA autokinase activity. (asm.org)
  • In the latter systems, signaling is initiated either by the direct binding of chemoeffectors or chemoeffector-loaded periplasmic binding proteins to the ligand binding domain (LBD) of chemoreceptors ( Matilla and Krell, 2017 ). (frontiersin.org)
  • The electron cryomicroscope allows us to see the arrangement of individual proteins inside cells in a lifelike state," says Jensen. (caltech.edu)
  • To do this, living cells are quickly frozen so that all the proteins are frozen in place-in the same places they were in the living state. (caltech.edu)
  • Cells are highly variable and specialized in both structure and function, although all must at some stage replicate proteins and nucleic acids, use energy, and reproduce themselves. (thefreedictionary.com)
  • To explore the plasticity of these proteins, we have developed a simple method for selecting cells that swim to target attractants. (nih.gov)
  • The authors conclude that in-vitro exposure to vanadium can alter the capacity of WEHI-3 cells to bind and respond to IFNg. (cdc.gov)
  • Typically, chemoreceptors bind ligands with elevated specificity and ligands serve as growth substrates. (frontiersin.org)
  • During embryogenesis, most neural crest‐derived sympathetic precursor cells undergo c‐jun‐dependent apoptosis as the availability of trophic factors (particularly nerve growth factor) becomes limiting (Estus et al , 1994 ). (embopress.org)
  • Fine sensory nerve fibres are found in juxtaposition to type I cells, which, unlike type II cells, contain electron-dense vesicles. (britannica.com)
  • A modified nerve cell in the retina that has dendrites but no axon. (tabers.com)
  • Chemoreceptors are specialized nerve cells which are designed to respond to chemical stimuli. (wisegeek.org)
  • All of these nerve cells send impulses back to the brain. (wisegeek.org)
  • 11 . The device of claim 1 , wherein the signal indicative of nerve traffic includes a signal indicative of nerve traffic from a chemoreceptor that is indicative of a blood gas concentration. (google.co.uk)
  • His team will be looking into the role of 'astrocytes' - cells that support and help the function of nerve cells in the brain. (scoop.co.nz)
  • In the past 10 to 15 years, astrocytes and how they work together with the nerve cells has become a real hot topic," says Professor Abraham. (scoop.co.nz)
  • 11. Central nervous system, insect brain and ventral chain of segmental ganglia, visceral nervous system, Nerve cell and histology od nerves. (muni.cz)
  • Vhl‐deficiency in mouse sympathoadrenal cells does not result in the appearance of tumors. (embopress.org)
  • Askanazy cells large eosinophilic cells found in the thyroid gland in autoimmune thyroiditis and Hürthle cell tumors. (thefreedictionary.com)
  • Nonchromaffin paragangliomas are issued from glomus cells, also known as glomus tumors. (wikipedia.org)
  • Tumors develop occasionally from neuroendocrine cells in the adrenal or thyroid glands. (merckvetmanual.com)
  • The trigeminal chemoreceptor cells are likely to be remnants of the phylogenetically ancient population of solitary chemoreceptor cells found in the epithelium of all anamniote aquatic vertebrates. (pnas.org)
  • often restricted to the cells of the alveolar epithelium (squamous alveolar cells and great alveolar cells) and alveolar phagocytes. (thefreedictionary.com)
  • Arias-Stella cells columnar cells in the endometrial epithelium which have a hyperchromatic enlarged nucleus and which appear to be associated with chorionic tissue in an intrauterine or extrauterine site. (thefreedictionary.com)
  • basal granular cells APUD cells located at the base of the epithelium at many places in the gastrointestinal tract. (thefreedictionary.com)
  • Embedded in the olfactory epithelium are three types of cells: supporting cells, basal cells, and OSNs. (wikipedia.org)
  • In the epithelium of the lower airways, a cell type of unknown function has been termed "brush cell" because of a distinctive ultrastructural feature, an apical tuft of microvilli. (fraunhofer.de)
  • Scientists believe that this sensitivity is due to the way the hundreds of chemoreceptors cluster together in the bacterial cell. (caltech.edu)
  • In summary, type-1 cell mitochondria display extraordinary oxygen sensitivity commensurate with a role in oxygen sensing. (nihr.ac.uk)
  • In this study, we sought to determine whether nicotine increases peripheral chemoreceptor sensitivity. (ahajournals.org)
  • One of the remarkable things about this system," says Jensen, "is that the chemoreceptors are exquisitely sensitive to changes in the concentrations of positive and negative stimuli. (caltech.edu)
  • Most sensory systems use specialized sensory cells that link stimuli in the outside world to the nervous system. (pnas.org)
  • Chemoreceptor cells may monitor external stimuli, as in TASTE and OLFACTION, or internal stimuli, such as the concentrations of OXYGEN and CARBON DIOXIDE in the blood. (uchicago.edu)
  • Ligand-binding sites of the bacterial chemoreceptors. (asm.org)
  • Most bacterial chemoreceptors are functionally unannotated and are characterized by a diversity in the structure of their ligand binding domains (LBDs). (asm.org)
  • Chemoreceptors are typically composed of a cytosolic methyl-accepting signaling domain and a ligand binding domain (LBD) that is frequently located in the extracytoplasmic space. (asm.org)
  • However, there is a chemoreceptor family that has a broad ligand specificity including many compounds that are not of metabolic value. (frontiersin.org)
  • This study indicates that the metabolic potential of compounds is an important parameter in the molecular recognition by broad ligand range chemoreceptors. (frontiersin.org)
  • Contrary to generally held beliefs Vhl is not a tumor suppressor gene in all cells. (embopress.org)
  • The size and complexity of the chemoreceptor gene families also facilitate studies of promoter elements using paralogous and orthologous comparisons, as well as other aspects of gene family and genome evolution. (nih.gov)
  • This points to a mechanism by which cells are able to use translation elongation and the geometric constraints of the cell to fine-tune organelle-specific gene expression through mRNA localization. (elifesciences.org)
  • Feeding state, insulin and NPR-1 modulate chemoreceptor gene expression via integration of sensory and circuit inputs. (sigmaaldrich.com)
  • On the other hand, too much ventilation depresses the partial pressure of carbon dioxide, which leads to a reduction in chemoreceptor activity and a diminution of ventilation. (britannica.com)
  • Carbon dioxide increases the acidity of the fluid surrounding the cells but also easily passes into cells and thus can make the interior of cells more acid. (britannica.com)
  • The human respiratory system , working in conjunction with the circulatory system , supplies oxygen to the body's cells, removing carbon dioxide in the process. (encyclopedia.com)
  • These peripheral chemoreceptors are going to detect things like oxygen-- in fact, that's probably one of the most important things they detect-- as well as carbon dioxide and pH. (khanacademy.org)
  • In work funded by the National Institutes of Health and reported in the Oct. 26 issue of the journal Genome Research , Robertson and postdoctoral research associate Kevin W. Wanner identified the family of honey bee chemoreceptors that deals with smell and taste. (phys.org)
  • Aqueous chemical compounds come into contact with chemoreceptors in the mouth, such as taste buds on the tongue, and trigger responses. (wikipedia.org)
  • Chemoreceptors located within taste buds. (encyclopedia.com)
  • We have chemoreceptors called taste buds. (hubpages.com)
  • In mammals, all new cells arise from existing cells through cell division, and an animal's growth results largely from increases in the number of its cells, most of which differentiate into specialized cell types to form the body's various tissues. (thefreedictionary.com)
  • The relative increases in zymosan stimulated O2- and hydrogen-peroxide production were lower than in control cells. (cdc.gov)
  • Motile A. brasilense cells respond tactically not only by biasing the probability of changes in the swimming direction of the polar flagellum (changes in swimming reversal frequency, equivalent to "tumbles" of E. coli ) but also by modulating transient increases in swimming velocity ( 6 ) ( Fig. 1 ). (asm.org)
  • Cells specialized to detect chemical substances and relay that information centrally in the nervous system. (uchicago.edu)
  • The nervous system has chemoreceptors that send information to the brain where it is interpreted as different tastes and smells. (arn.org)
  • For one, the chemoreceptor superfamily has many attributes that facilitate general inferences regarding molecular evolution. (genetics.org)
  • In recent years, in vitro experiments on PC12 cells have suggested that the von Hippel-Lindau (VHL) protein might participate in the molecular cascade leading to apoptosis of sympathetic progenitor cells and that impairment of this protein could predispose to pheochromocytomas, a tumor of the adrenal gland, in adulthood (Lee et al , 2005 ). (embopress.org)
  • The protein NahY thus appears to function as a chemoreceptor for naphthalene or a related compound. (asm.org)
  • When cells are migrating, caveolin-1, the principal protein component of caveolae, is excluded from the leading edge and polarized at the cell rear. (cdc.gov)
  • The strongest repellent response was observed for the polyamine spermidine, and we demonstrate that this response involves the low-abundance chemoreceptor Trg and the periplasmic binding protein PotD of the spermidine uptake system. (nature.com)
  • Gozal D, Hakim F, Kheirandish-Gozal L. Chemoreceptors, baroreceptors, and autonomic deregulation in children with obstructive sleep apnea. (uchicago.edu)
  • this study investigates the mechanisms by which H(2)S excites carotid body type 1 cells. (ox.ac.uk)
  • We investigated the mechanisms underlying carotid body (CB) glomus cells activation by low glucose. (diabetesjournals.org)
  • The molecular mechanisms used to sense glucopenia are poorly studied, although it is known that the most frequent response recorded in low glucose-sensing cells is a depolarization, which leads to the release of transmitters or hormones. (diabetesjournals.org)
  • Nevertheless, the precise mechanisms whereby glomus cells are activated by low glucose are unknown. (diabetesjournals.org)
  • Our conclusion is that the ribbed hairs are chemoreceptors, not spigots. (biologists.org)
  • Among the 21 sensory cells of each of these hairs there are two mechanosensitive ones, responding to the deflection of the hair shaft (Harris and Mill 1973, 1977) . (scholarpedia.org)
  • In insects, antennae act as distance chemoreceptors. (wikipedia.org)
  • Activating a Reserve Neural Stem Cell Population In Vitro Enables Engraftment and Multipotency after Transplantation. (harvard.edu)
  • A paraganglion (pl. paraganglia) is a group of non-neuronal cells derived of the neural crest. (wikipedia.org)
  • Mutagenesis experiments show that the five strongly conserved residues that stabilize the main-chain moiety of isoleucine are essential for binding, suggesting that the mechanism by which this family of chemoreceptors recognizes amino acids is highly conserved. (rcsb.org)
  • The data available indicate that there are two major chemoreceptor families at the functional level, namely, those that respond to amino acids or to Krebs cycle intermediates. (asm.org)
  • Interestingly, deletion of amino acids 1-60 did not prevent the polarization of caveolin-1 in human umbilical vein endothelial cells or wild-type mouse embryonic fibroblasts because of an interaction of Cav(61-178) mutant with endogenous caveolin-1. (cdc.gov)
  • Effects of exogenous hydrogen sulphide on calcium signalling, background (TASK) K channel activity and mitochondrial function in chemoreceptor cells. (ox.ac.uk)
  • acinar cell , acinic cell , acinous cell any of the cells lining an acinus, especially the zymogen-secreting cells of the pancreatic acini. (thefreedictionary.com)
  • It is known that besides O 2 tension, CB glomus cells can sense changes of blood CO 2 and pH ( 12 ), and it has recently been shown that in vitro glomus cells are also low-glucose detectors ( 10 , 11 , 14 ). (diabetesjournals.org)
  • In CB glomus cells, low glucose has been shown to produce external Ca 2+ -dependent catecholamine secretion in a dose-dependent manner and inhibition of macroscopic voltage-dependent K + currents ( 10 ). (diabetesjournals.org)
  • They are essentially of two types: chromaffin or sympathetic paraganglia made of chromaffin cells and nonchromaffin or parasympathetic ganglia made of glomus cells. (wikipedia.org)
  • The Wnt/beta-catenin asymmetry pathway patterns the atonal ortholog lin-32 to diversify cell fate in a Caenorhabditis elegans sensory lineage. (rochester.edu)
  • Type II cells secrete pulmonary surfactant. (thefreedictionary.com)
  • Type II cells, which are smaller and more numerous than Type I cells, secrete pulmonary surfactant. (tabers.com)
  • APUD cells [ a mine p recursor u ptake and d ecarboxylation] a group of cells that manufacture polypeptides and biogenic amines serving as hormones or neurotransmitters. (thefreedictionary.com)
  • Kumar P, Prabhakar NR. Peripheral chemoreceptors: function and plasticity of the carotid body. (uchicago.edu)
  • Peripheral chemoreceptor function after carbonic anhydrase inhibition during moderate-intensity exercise. (biomedsearch.com)
  • The body contains both direct and distant chemoreceptors, all of which play important roles in bodily function and daily life. (wisegeek.org)
  • Integration of ATAC-see with flow cytometry enables automated quantitation and prospective cell isolation as a function of chromatin accessibility, and it reveals a cell-cycle dependence of chromatin accessibility that is especially dynamic in G1 phase. (stanford.edu)
  • What is the function of the cell wall? (flashcardmachine.com)
  • Most important, the book provides the trends in the field as it contains results in the topics that are at the frontiers of future developments in O2-sensing in chemoreceptor cells. (environmental-expert.com)