Chemoreceptor Cells: 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.Carotid Body: 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.Aortic Bodies: 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).Almitrine: 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.Anoxia: Relatively complete absence of oxygen in one or more tissues.Catecholamines: A general class of ortho-dihydroxyphenylalkylamines derived from tyrosine.Oxygen: 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.Kv1.4 Potassium Channel: A fast inactivating subtype of shaker potassium channels that contains two inactivation domains at its N terminus.Shal Potassium Channels: 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, Tandem Pore Domain: 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.Rabbits: 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.Potassium: 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.Sodium Cyanide: 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.Tetraethylammonium: A potassium-selective ion channel blocker. (From J Gen Phys 1994;104(1):173-90)Dinitrophenols: Organic compounds that contain two nitro groups attached to a phenol.Thiourea: 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.Potassium Channels: 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.Large-Conductance Calcium-Activated Potassium Channels: 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.Membrane Potentials: 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).Respiration: 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).Carotid Sinus: 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.Carbon Dioxide: A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.Cell Hypoxia: A condition of decreased oxygen content at the cellular level.Paraganglia, Nonchromaffin: 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 Channels, Voltage-Gated: 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.Nifedipine: A potent vasodilator agent with calcium antagonistic action. It is a useful anti-anginal agent that also lowers blood pressure.Chemotaxis: The movement of cells or organisms toward or away from a substance in response to its concentration gradient.Electrophysiology: 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.Calcium: 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.Patch-Clamp Techniques: 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.Hypercapnia: A clinical manifestation of abnormal increase in the amount of carbon dioxide in arterial blood.Rats, Wistar: A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.Pressoreceptors: Receptors in the vascular system, particularly the aorta and carotid sinus, which are sensitive to stretch of the vessel walls.Reflex: 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.Glossopharyngeal Nerve: 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.Vagotomy: The interruption or removal of any part of the vagus (10th cranial) nerve. Vagotomy may be performed for research or for therapeutic purposes.Denervation: The resection or removal of the nerve to an organ or part. (Dorland, 28th ed)Cats: 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, Cultured: 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.Phrenic Nerve: 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.Medulla Oblongata: 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.Immunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.Respiratory Center: 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.Asphyxia: A pathological condition caused by lack of oxygen, manifested in impending or actual cessation of life.Apnea: A transient absence of spontaneous respiration.Neurons, Efferent: Neurons which send impulses peripherally to activate muscles or secretory cells.Respiratory Mechanics: 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.Pulmonary Ventilation: The total volume of gas inspired or expired per unit of time, usually measured in liters per minute.Cyanides: 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.Bacterial Proteins: Proteins found in any species of bacterium.Solitary Nucleus: 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.Vagus Nerve: 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).Receptors, Amino Acid: 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.Hyperoxia: 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)

*Solitary chemosensory cells

... (SCCs) (also called solitary chemoreceptor cells) are isolated elements located in epithelia of the ... Whitear M. Solitary chemoreceptor cells. In: Chemoreception in fishes. Hara T.J. (Ed) Chapman and Hall New York 1992; pp. 103- ... Identification of the taste cell G-protein alpha-gustducin in brush cells of the rat pancreatic duct system. Histochem Cell ... Solitary chemoreceptor cells in the nasal cavity serve as sentinels of respiration. Proc Natl Acad Sci USA 2003; 100: 8981-86. ...

*Chemesthesis

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 ...

*Hypoxia in fish

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 ...

*Carotid body

The carotid body is made up of two types of cells, called glomus cells: glomus type I cells are peripheral chemoreceptors, and ... Glomus type II cells resemble glial cells, express the glial marker S100 and act as supporting cells. The carotid body contains ... The carotid body (carotid glomus or glomus caroticum) is a small cluster of chemoreceptors and supporting cells located near ... This leads to depolarisation of the cell membrane which leads to Ca2+ entry, excitation of glomus cells and consequent ...

*E-4031

Postnatal development of E-4031-sensitive potassium current in rat carotid chemoreceptor cells. J Appl Physiol 98(4):1469-1477 ... 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 434:1-10 Sanguinetti MC, Jurkiewicz NK (1990) Two Components of Cardiac Delayed ...

*Chemoreceptor

Embedded in the olfactory epithelium are three types of cells: supporting cells, basal cells, and OSNs. While all three types ... This signal may be in the form of an action potential if the chemoreceptor is a neuron (nerve cell), or in the form of a ... A chemoreceptor, also known as chemosensor, is a specialized sensory receptor cell which transduces (responds to) a chemical ... Neuroscience portal Cell surface receptor Chemosensory clusters Chemoreceptor trigger zone Diffuse chemosensory system Haptic ...

*Chlamys hastata

The longer ones have sensitive chemoreceptor cells at their tip which can taste the water and allow the mollusc to react ... It has chemoreceptors on the mantle margins which detect the approach of a starfish and enable it to take evasive action. It ...

*Peripheral chemoreceptors

Each of these peripheral chemoreceptors is composed of type I glomus cells and type II glia-like cells. The type-I cells ... since fluctuations in pH can denature a cell's enzymes. Central chemoreceptors Chemoreceptors Control of respiration Gonzalez, ... Type II cells occur in a ratio of about 1 to 4 with type I cells. Their long bodies usually occur in close association with ... However, AMPK is an enzyme found in many more types of cells than chemoreceptors because it helps regulate metabolism. The ...

*Sea anemone

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 ...

*Taste bud

Some, however, are found in the interior of the bud between the gustatory cells. The gustatory (taste) cells, a chemoreceptor, ... 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 ...

*KCNC3

K+ channel may function as an oxygen sensor complex in airway chemoreceptors and small cell lung carcinoma cell lines". Proc. ...

*Sensory neuron

The aortic bodies and carotid bodies contain clusters of glomus cells - peripheral chemoreceptors that detect changes in ... The five basic classes of neurons within the retina are photoreceptor cells, bipolar cells, ganglion cells, horizontal cells, ... bipolar cell, and the ganglion cell. The first action potential occurs in the retinal ganglion cell. This pathway is the most ... There are two types of hair cells: inner and outer. The inner hair cells are the sensory receptors . Problems with sensory ...

*Evolution of the eye

... even photoreceptor cells may have evolved more than once from molecularly similar chemoreceptors, and photosensitive cells ... ganglion cells, amacrine cells, horizontal cells, and bipolar cells before they reach the light-sensitive rods and cones that ... 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 in a ...

*Aortic body

The chemoreceptors responsible for sensing changes in blood gases are called glomus cells. It gives feedback to the medulla ... The aortic body is one of several small clusters of peripheral chemoreceptors known as glomus cells, baroreceptors, and ... When a distinction is made, the "aortic bodies" are chemoreceptors which regulate the circulatory system, while the "paraaortic ... Carotid body Control of respiration Peripheral chemoreceptors Aortic Bodies at the US National Library of Medicine Medical ...

*Anatomy

In more complex animals, specialized receptor cells such as chemoreceptors and photoreceptors are found in groups and send ... Metazoans do not include the sponges, which have undifferentiated cells. Unlike plant cells, animal cells have neither a cell ... The outer epithelial layer may include cells of several types including sensory cells, gland cells and stinging cells. There ... The cells of single-cell protozoans have the same basic structure as those of multicellular animals but some parts are ...

*Nematode chemoreceptor

Cell. 83 (2): 207-218. doi:10.1016/0092-8674(95)90162-0. PMID 7585938. This article incorporates text from the public domain ... Nematode chemoreceptors are chemoreceptors of nematodes. Animals recognise a wide variety of chemicals using their senses of ...

*Glomus body

The glomus body is not to be confused with the glomus cell which is a kind of chemoreceptor found in the carotid bodies and ... The glomus bodies in the skin and elsewhere are unusual in that their "endothelial cells" exist in multiple layers of cells ... Endothelial cells form a single, continuous layer that lines all vascular segments. Junctional complexes keep the endothelial ... cells together in arteries but are less numerous in veins. The organization of the endothelial cell layer in capillaries varies ...

*Glomus cell

A glomus cell (type I) is a peripheral chemoreceptor, mainly located in the carotid bodies and aortic bodies, that helps the ... The signalling within the chemoreceptors is thought to be mediated by the release of neurotransmitters by the glomus cells, ... Autonomic ganglia innervate the glomus cells, and some presynaptic sympathetic ganglia synapse with glomus cells. The nerve ... The glomus cells have a high metabolic rate and good blood perfusion and thus are sensitive to changes in arterial blood gas ...

*Paraganglion

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 ... Nonchromaffin paragangliomas are issued from glomus cells, also known as glomus tumors. They are usually benign. They are ... They are essentially of two types: chromaffin or sympathetic paraganglia made of chromaffin cells and nonchromaffin or ...

*Paraganglioma

These cells normally act as special chemoreceptors located along blood vessels, particularly in the carotid bodies (at the ... Individual tumor cells are polygonal to oval and are arranged in distinctive cell balls, called Zellballen. These cell balls ... With immunohistochemistry, the chief cells located in the cell balls are positive for chromogranin, synaptophysin, neuron ... The sustentacular cells are S-100 positive and focally positive for glial fibrillary acidic protein. By histochemistry, the ...

*Chemosensor

... may refer to: Chemoreceptor, a specialized sensory receptor cell which transduces (responds to) a chemical ...

*Neuroendocrine cell

... small cell carcinoma of the lung, and bronchial carcinoid tumor. PNEC may play a role with chemoreceptors in hypoxia detection ... Neuroendocrine cells are cells that receive neuronal input (neurotransmitters released by nerve cells or neurosecretory cells) ... The adrenal medullary cells are controlled by the sympathetic division of the autonomic nervous system. These cells are ... APUD cells are considered part of the neuroendocrine system, and share many staining properties with neuroendocrine cells. ...

*Serotonin

This activates 5-HT3 receptors in the chemoreceptor trigger zone that stimulate vomiting. The enterochromaffin cells not only ... are located on the cell membrane of nerve cells and other cell types in animals, and mediate the effects of serotonin as the ... Serotonin can also be synthesized, albeit at very low levels, in the bone cells. It mediates its actions on bone cells using ... Cell. 135 (5): 825-37. doi:10.1016/j.cell.2008.09.059. PMC 2614332 . PMID 19041748. Lay summary - Science Daily. CS1 maint: ...

*Organ of Zuckerkandl

When a distinction is made, the "aortic bodies" are chemoreceptors which regulate circulation, while the "paraaortic bodies" ... are the chromaffin cells which manufacture catecholamines. Its physiological role is thought to be of greatest importance ... "Cell Loss and Autophagy in the Extra-Adrenal Chromaffin Organ of Zuckerkandl are Regulated by Glucocorticoid Signalling". ...

*Enteroendocrine cell

In a sense they are known to act as chemoreceptors, initiating digestive actions and detecting harmful substances and ... Enterochromaffin-like cells are enteroendocrine and neuroendocrine cells also known for their similarity to chromaffin cells ... Enterochromaffin cells are enteroendocrine and neuroendocrine cells with a close similarity to adrenomedullary chromaffin cells ... Enteroendocrine cells of the intestine are the most numerous endocrine cells of the body. They constitute an enteric endocrine ...

*Olfactory receptor neuron

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 ...
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 ...
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 ...
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.
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 ...
Central chemoreceptors of the central nervous system, located on the ventrolateral medullary surface in the vicinity of the exit of the 9th and 10th cranial nerves, are sensitive to the pH of their environment. These act to detect the changes in pH of nearby cerebrospinal fluid (CSF) that are indicative of altered oxygen or carbon dioxide concentrations available to brain tissues. An increase in carbon dioxide causes tension of the arteries, often resulting from decreased CO2 output (hypercapnia), indirectly causes the blood to become more acidic; the cerebrospinal fluid pH is closely comparable to plasma, as carbon dioxide easily diffuses across the blood-brain barrier. However, a change in plasma pH alone will not stimulate central chemoreceptors as H+ 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 ...
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...
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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 ...
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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 ...
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
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][18] These chemoreceptors are sensitive to the pH and levels of carbon dioxide in the cerebrospinal fluid.[12][10][18] (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 ...
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. ...
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 ...
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 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...
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.
... 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
The mechanism of oxygen sensing in arterial chemoreceptors is unknown but has often been linked to mitochondrial function. A common criticism of this hypothesis is that mitochondrial function is insensitive to physiological levels of hypoxia. Here we investigate the effects of hypoxia (down to 0.5% O2) on mitochondrial function in neonatal rat type-1 cells. The oxygen sensitivity of mitochondrial [NADH] was assessed by monitoring autofluorescence and increased in hypoxia with a P50 of 15 mm Hg (1 mm Hg = 133.3 Pa) in normal Tyrode or 46 mm Hg in Ca(2+)-free Tyrode. Hypoxia also depolarised mitochondrial membrane potential (m, measured using rhodamine 123) with a P50 of 3.1, 3.3 and 2.8 mm Hg in normal Tyrode, Ca(2+)-free Tyrode and Tyrode containing the Ca(2+) channel antagonist Ni(2+), respectively. In the presence of oligomycin and low carbonyl cyanide 4-(trifluoromethoxy) phenylhydrazone (FCCP; 75 nm) m is maintained by electron transport working against an artificial proton leak. Under these
Abstract: Carbon dioxide retention is common in divers during water immersion. This puts divers at risk for carbon dioxide toxicity. The carotid body chemoreceptors contribute to the control of ventilation and when blood oxygen content is high, ventilation decreases. This results in the increased risk of carbon dioxide retention. Therefore, we are investigating the role of the carotid body chemoreceptors in ventilatory control during hyperbaric exposures when blood oxygen content is elevated ...
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The inappropriate sustained SNA increase in OSA patients likely contributes to hypertension, organ damage, and mortality; however, it is unclear how excessive SNA develops in these patients. Several factors, including obesity and increased carotid body chemoreceptor sensitivity due to intermittent hypoxia, have been considered. Obesity could mechanically obstruct the airway and increase SNA through leptin, insulin, angiotensin, and cytokine actions; however, many OSA patients are not obese (23). Carotid body hypersensitivity as a result of intermittent hypoxia has been confirmed in animal models of OSA. In fact, plasticity of the carotid body glomus cells with long-term sensory facilitation and sensitization have been reported (18, 24) and associated with ROS and NOX2-dependent accumulation of HIF1 and the transcriptional coactivator CREB-binding protein (25). Central neuroplasticity. A provocative possibility for OSA-associated SNA dysfunction is that excessive activation of CNS nuclei induces ...
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Running to catch the bus might be the only exercise some of us get during the day, but your leg muscles arent the only muscles getting an unexpected workout. Christina Spengler explains that our respiratory systems also have to rise to the challenge. But when an endurance athlete runs for the bus at the same speed, they hardly get out of breath, because they breathe less. Spengler also knew that the athletes peripheral chemosensory system, the system which constantly monitors the bodys levels of key metabolites as well as carbon dioxide and oxygen, is less sensitive than untrained peoples. Spengler wondered if it was the act of exercising the whole body that reset the chemoreceptors, or could heavy breathing alone reduce the chemoreceptors sensitivity? Working with her team, she tested how endurance athletes respiratory systems responded to six weeks of heavy breathing training, and was astonished to find that the breathing exercises alone had somehow reduced the athletes chemoreceptors ...
Odor signals mediate a variety of behaviors in animals across a diversity of taxa. Despite dramatic morphological differences between animals from different taxa, several important features of olfactory system organization and processing are similar across animals. Because of this similarity, a number of different organisms including mammals, insects, and decapod crustaceans serve as valuable model systems for understanding general principles of olfactory processing. As in other organisms, including both vertebrates and insects, the chemosensory system of decapod crustaceans is organized into multiple anatomically distinct neuronal pathways. The two main pathways (the aesthetasc/ olfactory lobe pathway and non-aesthetasc/ lateral antennular neuropil pathway) originate in different populations of antennular sensilla and project to different neuropils in the brain. The functional significance of this parallel organization is not well understood in crustaceans or in many other species. Although in some
Rhodobacter sphaeroides has multiple homologues of most of the Escherichia coli chemotaxis genes, organized in two major operons and other, unlinked, loci. These include cheA1 and cheW1 (che Op1) and cheA2, cheW2 and cheW3 (che Op2). We have deleted each of these cheA and cheW homologues in-frame and examined the chemosensory behaviour of these strains on swarm plates and in tethered cell assays. In addition, we have examined the effect of these deletions on the polar localization of the chemoreceptor McpG. In E. coli, deletion of either cheA or cheW results in a non-chemotactic phenotype, and these strains also show no receptor clustering. Here, we demonstrate that CheW2 and CheA2 are required for the normal localization of McpG and for normal chemotactic responses under both aerobic and photoheterotrophic conditions. Under aerobic conditions, deletion of cheW3 has no significant effect on McpG localization and only has an effect on chemotaxis to shallow gradients in swarm plates. Under
Background K+ channels of the TASK family are believed to participate in sensory transduction by chemoreceptor (glomus) cells of the carotid body (CB). However, studies on the systemic CB-mediated ventilatory response to hypoxia and hypercapnia in TASK1- and/or TASK3-deficient mice have yielded conflicting results. We have characterized the glomus cell phenotype of TASK-null mice and studied the responses of individual cells to hypoxia and other chemical stimuli. CB morphology and glomus cell size were normal in wild-type as well as in TASK1/ or double TASK1/3/ mice. Patch-clamped TASK1/3-null glomus cells had significantly higher membrane resistance and less hyperpolarized resting potential than their wild-type counterpart. These electrical parameters were practically normal in TASK1/ cells. Sensitivity of background currents to changes of extracellular pH was drastically diminished in TASK1/3-null cells. In contrast with these observations, responsiveness to hypoxia or ...
Symposium on Signalling pathways in acute oxygen sensing, held at the Novartis Foundation, London, 25-27 January 2005. Editors: Derek J. Chadwick (Organizer) and Jamie Goode.. This symposium is based on a proposal made by Jeremy Ward.. Michael Duchen Chairs introduction.. Gregg L. Semenza, Larissa A. Shimoda and Nanduri R. Prabhakar Regulation of gene expression by Hypoxia-Inducible Factor.. Discussion.. Ineke P. Stolze, David R. Mole and Peter J. Ratcliffe Regulation of HIF: prolyl hydroxylases.. Discussion.. General discussion I.. Daniel Peet and Sarah Linke Regulation of HIF: asparaginyl hydroxylation.. Discussion.. José López-Barneo, Patricia Ortega-Sáenz, José I. Piruat and María García-Fernández Oxygen-sensing by ion channels and mitochondrial function in carotid body glomus cells.. Discussion.. Keith J. Buckler, Beatrice A. Williams, Rodrigo Varas Orozco and Christopher N. Wyatt The role of TASK-like potassium channels in oxygen sensing in the carotid body.. Discussion.. Nanduri ...
The bacterial chemotaxis receptors are transmembrane receptors with a simple signalling pathway which has elements relevant to the general understanding of signal recognition and transduction across membranes, how signals are relayed between molecules in a pathway, and how adaptation to a persistent signal is achieved. Bacterial chemotaxis receptors are composed of a ligand-binding domain, a transmembrane domain consisting of two helices TM1 and TM2, and a cytoplasmic domain. All known bacterial chemotaxis receptors have a highly conserved cytoplasmic domain, which unites signals from different ligand domains into a single signalling pathway to flagella motors. ...
An easy access to amine appended spiro[indoline-3,4-pyridine] ON-OFF chemosensor by one pot four-component reaction using commercially available and environmentally benign catalytic amount of molecular I2 (10 mol %) in aqueous ethanol at ambient temperature is described. The generated system can be utilized
Normally breathing is controlled by a reflex that responds to the levels of carbon dioxide (CO2) in the blood. The change in breathing that results from a change in the bloods CO2 concentration is called the chemoreflex.. In heart failure, a condition where the heart muscle is damaged and can not pump as well, this reflex is exaggerated. The result of this can be breathing conditions characterised by patients hyperventilating at times and at other times taking very shallow breaths or even stopping altogether. In the past the only way of measuring this chemoreflex was to get patients to breathe into a large container and to rebreathe their exhaled air and allow the CO2 to rise over time, whilst keeping the oxygen constant. The proportion by which the ventilation increases with increasing carbon dioxide is the chemoreflex gain. Unfortunately, because this test takes a long time to conduct, requires specialist knowledge and equipment it has not been possible to measure this reflex on exercise. ...
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Astrocytes (or glial cells), previously assumed to be passive players in brain physiology, may play a functional role in a number of complex behaviors. The central chemosensory control of breathing involves highly specialized neuronal populations in the brainstem, but what about astrocytes? Gourine et al. now present evidence that glial cells may help to control breathing. A number of techniques were used to reveal glial calcium rises in vitro that elicit a depolarization of neurons in the primary locus for central respiratory chemosensitivity. The depolarization in these neurons is evoked by vesicular release of ATP in neighboring astrocytes in response to the fall in extracellular pH. Thus, brainstem astrocytes have the ability to sense changes in blood and brain CO2, and pH directly, and may control the activity of the respiratory neuronal networks to regulate breathing.. A. V. Gourine, V. Kasymov, N. Marina, F. Tang, M. F. Figueiredo, S. Lane, A. G. Teschemacher, K. M. Spyer, K. Deisseroth, ...
We all know sushi rolls, but just to be sure here is an easy definition: a wrapper encircles rice which holds a precious bit of fish. To make a sushi role is an art and the same holds true for molecular sushi that is made of two lipoproteins as wrapper, lipids as rice, and membrane proteins as filling. Sushi rolls are for eating. Molecular sushi roles are for holding membrane proteins in place for physical analysis; they actually come only in sliced form, one disc at a time. Due to their size, the discs are called nanodiscs. Since membrane proteins are notoriously difficult to study experimentally due to their need to be in a "native" membrane environment, nanodiscs are a great tool, furnishing a membrane environment that has been used to embed a variety of membrane proteins for biochemical assay, including cytochrome P450s, rhodopsin, bacterial chemoreceptors, blood clotting factors, and translocation proteins. Unfortunately, it is difficult to make either real or molecular sushi rolls ...
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Advances in experimental medicine and biology.; Arterial chemoreception: from molecules to systems; Ontario, Canada, 2011; Jul, 2012, 199-206 -- Dordrecht; London; Springer; c2012 Part; (pages 199-206) -- ...
Cyprid larva of a Barnacle (Cypris). During this stage the larva does not feed but uses its specialized chemoreceptors to search for a place to settle. Darkfield, LM X100. - Stock Image C008/6400
To investigate which neurons in the medulla oblongata produced the nuclear protein FOS during stimulation of respiration by hypercapnia, we subjected six anaesthetized cats to 10% CO2 in air for one hour. Four animals inhaled room air. Coronal sections from the medulla oblongata were processed for FOS immunohistochemistry. Only the retrotrapezoid nucleus (RTN) of the animals exposed to CO2 contained a large population of labelled neurons. This indicates that RTN neurons are strongly activated during hypercapnia.
... : Amiloride inhibition of basolateral membrane depolarization in response to increased bath osmolality correlates with afferent neural activity and behavior ...
Increased controller gain occurs if the sensitivity of chemoreceptors is increased.37 Various hormones and drugs can alter the human chemoreceptor sensitivity, including the endogenous catecholamines noradrenaline and adrenaline.38,39 Levels of both hormones are increased in the blood and urine of patients with heart failure, probably as compensation for cardiac pump failure.40 Increased circulating concentrations of these catecholamines might increase the responsiveness of the respiratory controller to carbon dioxide, leading to hyperventilation.41,42 Latent hyperventilation during wakefulness is a common finding in these patients and a relationship between an abnormally increased ventilatory response to carbon dioxide during the day and periodic breathing during sleep has been observed.43 Their Paco2 is typically in the lower normal range or even below, keeping ventilation closer to the threshold of apnoea. Javaheri44 showed that patients with CHF and CSAS had a significantly greater ...
Electron micrographs of sections of the labellar chemosensilla of the blowfly, Phormia regina, showed that treatment with sodium deoxycholate (DOC; 7.2 mM for 2 min) destroyed the distal processes of the receptors from up to 10 microns from the tip of the sensillum, but these processes regenerated almost completely within 0.5 h. However, when DOC treatment was preceded by colchicine treatment (25 mM for 2 min), greater than 10 h was required for complete regeneration. Sugar receptor responses supported these findings and disclosed a more detailed time course of regeneration after DOC treatment: without colchicine pretreatment, the destroyed distal process completely regenerated in 0.3-1.0 h, but with pretreatment, regeneration began at 3 h and reached the chemosensillar tip at 8 h at the earliest. Hardly any depression of the response was observed for 8 h after treatment with colchicine alone, but a transient depression was detected at 12 h. Based on these results, the role of microtubules in ...
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going Data Science Methods for Department of Defense Personnel and download Frontiers in Arterial Chemoreception 1996 classes. Washington, DC: The National Academies Press. effective programs of Sciences, Engineering, and Medicine. working Data Science Methods for Department of Defense Personnel and download Frontiers in Arterial Chemoreception opponents. Washington, DC: The National Academies Press. Many models of Sciences, Engineering, and Medicine. swelling Data Science Methods for Department of Defense Personnel and download Frontiers days. Washington, DC: The National Academies Press. National sensors of Sciences, Engineering, and Medicine. coding Data Science Methods for Department of Defense Personnel and download Frontiers in Areas. Washington, DC: The National Academies Press. objective abstracts of Sciences, Engineering, and Medicine. Strengthening Data Science Methods for Department of Defense Personnel and download strategies. Washington, DC: The National Academies Press. everyday ...
The present study examined the role of branchial and orobranchial O2 chemoreceptors in the cardiorespiratory responses, aquatic surface respiration (ASR), and the development of inferior lip swelling in tambaqui during prolonged (6 h) exposure to hypoxia. Intact fish (control) and three groups of denervated fish (bilateral denervation of cranial nerves IX+X (to the gills), of cranial nerves V+VII (to the orobranchial cavity) or of cranial nerves V alone), were exposed to severe hypoxia (PwO2=10 mmHg) for 360 min. Respiratory frequency (fr) and heart rate (fh) were recorded simultaneously with ASR. Intact (control) fish increased fr, ventilation amplitude (VAMP) and developed hypoxic bradycardia in the first 60 min of hypoxia. The bradycardia, however, abated progressively and had returned to normoxic levels by the last hour of exposure to hypoxia. The changes in respiratory frequency and the hypoxic bradycardia were eliminated by denervation of cranial nerves IX and X but were not affected by ...
Increased sympathetic activity is a well-known pathophysiological mechanism in insulin resistance (IR) and hypertension (HT). The carotid bodies (CB) are peripheral chemoreceptors that classically respond to hypoxia by increasing chemosensory activity in the carotid sinus nerve (CSN), causing hyperventilation and activation of the sympathoadrenal system. Besides its role in the control of ventilation, the CB has been proposed as a glucose sensor implicated in the control of energy homeostasis. However, to date no studies have anticipated its role in the development of IR. Herein, we propose that CB overstimulation is involved in the etiology of IR and HT, core metabolic and hemodynamic disturbances of highly prevalent diseases like the metabolic syndrome, type 2 diabetes, and obstructive sleep apnoea. We demonstrate that CB activity is increased in IR animal models and that CSN resection prevents CB overactivation and diet-induced IR and HT. Moreover, we show that insulin triggers CB, ...
While there is little information specific to the mating habits of thin-legged wolf spiders, mating habits for wolf spiders (Lycosidae) in general are known. Males typically mount females so that they are facing opposite directions. Females must twist and invert their abdomen so that males can reach around to the ventral side of their abdomen. Males use their pedipalps to transfer sperm into the females epigynum. Thin-legged wolf spiders mate in May and June, after sub-adults that overwintered have molted into their reproductive phase. Mating may reportedly last about 60 minutes in this species. While the catalysts of mate attraction are unknown in this species, females from other wolf spider species, including other species of Pardosa, use pheromones or other chemicals to attract males. Contact pheromones are often used; males detect these pheromones with chemoreceptors on their forelegs and palps. Visual and vibratory cues may also be used. (Buddle, 2002; Jiao, et al., 2011; Stratton, et al., ...
Hypoxic chemotransduction in the carotid body requires release of excitatory transmitters from type I cells that activate afferent sensory neurones. Transmitter release is dependent on voltage-gated Ca2+ entry which is evoked by membrane depolarization. This excitatory response to hypoxia is initiated by inhibition of specific O2 sensitive K+ channels, of which several types have been reported. Here, we discuss mechanisms which have been put forward to account for hypoxic inhibition of type I cell K+ channels. Whilst evidence indicates that one O2 sensitive K+ channel, BKCa, may be regulated by gasotransmitters (CO and H2S) in an O2-dependent manner, other studies now indicate that activation of AMP-activated protein kinase (AMPK) accounts for inhibition of both BKCa and leak O2 sensitive K+ channels, and perhaps also other O2sensitive K+ channels reported in different species. We propose that type I cell AMPK activation occurs as a result of inhibition of mitochondrial oxidative phosphorylation, and
ABOUT POTASSIUM CYANIDE (1G). Potassium Cyanide (1g) is considered to be a highly toxic powder. It is used for many purposes that are not discussed here.. HOW TO USE POTASSIUM CYANIDE (1G)?. Potassium Cyanide (1g) should be used after talking to your concerned doctor, physician, or healthcare provider. Read the medication guide for more information about it.. Hit your requirements for Potassium Cyanide (1g) at our online pharmacy today. We are dealing with this product at reasonable prices. You can bring your order to us and we will deliver the same at your mentioned location within a short period of time. Place your order today!. ...
Different physiological pathways may lead to shortness of breath including via ASIC chemoreceptors, mechanoreceptors, and lung receptors.[13]. It is thought that three main components contribute to dyspnea: afferent signals, efferent signals, and central information processing. It is believed the central processing in the brain compares the afferent and efferent signals; and dyspnea results when a "mismatch" occurs between the two: such as when the need for ventilation (afferent signaling) is not being met by physical breathing (efferent signaling).[17]. Afferent signals are sensory neuronal signals that ascend to the brain. Afferent neurons significant in dyspnea arise from a large number of sources including the carotid bodies, medulla, lungs, and chest wall. Chemoreceptors in the carotid bodies and medulla supply information regarding the blood gas levels of O2, CO2 and H+. In the lungs, juxtacapillary (J) receptors are sensitive to pulmonary interstitial edema, while stretch receptors signal ...
The novel findings presented in this study are: 1) a population difference between patients with narcolepsy-cataplexy and age-matched controls with regard to hypoxic chemosensitivity; and 2) an association between DQB1*0602 and acute ventilatory responsiveness to progressive hypoxia. While narcolepsy-cataplexy patients do have different sleep values, AHI and lowest arterial ozygen saturation (Sa,O2) were not defining factors for the group differences in ventilatory chemosensitivity.. Contrary to results obtained in hypocretin gene knockout mice, hypercapnia responses were not affected by disease or marker state. Unlike knockout mice, where both the gene and protein are absent, in patients with narcolepsy, hypocretin-1 is often detected at some level in the CSF 9. We suspect that the effects of hypocretin on chemoresponsiveness, if present, are below a threshold for detection.. Our findings implicate DQB1*0602, or a gene located nearby, as a regulator of hypoxic responses. While DQB1*0602 is an ...
p>The checksum is a form of redundancy check that is calculated from the sequence. It is useful for tracking sequence updates.,/p> ,p>It should be noted that while, in theory, two different sequences could have the same checksum value, the likelihood that this would happen is extremely low.,/p> ,p>However UniProtKB may contain entries with identical sequences in case of multiple genes (paralogs).,/p> ,p>The checksum is computed as the sequence 64-bit Cyclic Redundancy Check value (CRC64) using the generator polynomial: x,sup>64,/sup> + x,sup>4,/sup> + x,sup>3,/sup> + x + 1. The algorithm is described in the ISO 3309 standard. ,/p> ,p class="publication">Press W.H., Flannery B.P., Teukolsky S.A. and Vetterling W.T.,br /> ,strong>Cyclic redundancy and other checksums,/strong>,br /> ,a href="http://www.nrbook.com/b/bookcpdf.php">Numerical recipes in C 2nd ed., pp896-902, Cambridge University Press (1993),/a>),/p> Checksum:i ...
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We report a modular design of vesicular chemosensors by co-embedding a Tb(III) complex and a receptor-sensitizer conjugate in phospholipid vesicles. The binding of phosphate anions to the vesicle surface in aqueous media is detected by a decrease in Tb(III) phosphorescence. The sensory response can be modulated by a variation in the membrane fluidity. ...
We have constructed fluorescent chemosensors for metal ions, especially, Zn(II), Cu(II), and Mn(II). Besides the synthesis of interesting new probes, we have explored new spectroscopic methods of visualization, especially to quantify both the amount of probe and metal in the sample. Our main focus recently has been on cellular and tissue transport and distribution of Mn(II), which is important in neurobiology including calcium channel function and Manganese-Enhanced Magnetic Resonance Imaging (MEMRI). ...
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People tend to get sick, over and over again, due to similar causes and habitual imbalances that are unique to the person. Your body type summarizes this tendency, showing you the type of conditions and imbalances that frequently challenge your health & wellness. Using body type, you can also identify remedies likely to improve your strength and resiliency. Your body type identifies physical and mental characteristics as well as your personal strengths and weaknesses. The calculation of your body type is based on your medical history. The 3 functional body types (doshas), are Catabolic (Vata), Metabolic (Pitta), and Anabolic (Kapha). Catabolic individuals tend to break down body mass into energy. Metabolic individuals tend to burn or use energy. Anabolic individuals tend to store energy as body mass. Catabolic people tend to be easily stimulated, hyperactive, underweight and dry. Metabolic people tend to be rosy-cheeked, easily irritated, focused, driven, and easily inflamed. Anabolic people ...
Chemodectomas are generally benign tumors that grow from the chemoreceptor tissue of the body. These are the tissues most sensitive to chemical changes in the body, such as oxygen content and pH levels in the blood.
Your body type shows how your strengths, as well as how your body typically goes out of balance. It also shows how your body responds to the environment. Your body type is comprised of certain qualities and affects every part of you - your physical and mental characteristics as well as your personal strengths and weaknesses. This is because your body type is based on how your body uses energy. Ayurveda has 3 body types (doshas), called Vata, Pitta, and Kapha. Vata spends energy. Pitta burns energy. Kapha stores energy. Vata people tend to be easily stimulated, hyperactive, underweight and dry. Pitta people tend to be hot, focused, driven, and easily inflamed. Kapha people are heavy, stable and grounded, but if they store too much energy, they could gain weight easily and have congestion. Learn More ...
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Journal of Clinical and Diagnostic Research aims to publish findings of doctors at grass root level and post graduate students, so that all unique medical experiences are recorded in literature.
treat nausea and vomiting act by inhibiting dopamine or serotonin receptors in the brain act to block various pathways preventing signals from reaching the VC or CTZ Physiologic vomiting triggers Stimulus of the vomiting center - VC Stimulus of the chemoreceptor trigger zone - CTZ Secondary to nausea and vomiting is dehydration excessive…
Third, the residual volume doesnt allow sudden changes in the outside concentration of air to affect your internal homeostasis. It takes 16 to 20 breaths for the outside air to affect your residual volume. This gives ample of time for your chemoreceptors to detect the slight changes in pH and respond. ...
(2008) Siju et al. Arthropod Structure and Development. Female mosquitoes depend on blood to complete their reproductive cycle and rely mainly on chemosensory systems to obtain blood meals. An immunocytochemical analysis reveals a number of serotonin-im...
All body types can gain or lose weight but the degree and rate at which they do varies... Exercise and diet for body types... body type pictures of celebrities ...
Sensitive, specific, and accurate methods to assay chemosensitivity are needed to (1) screen new therapeutic agents, (2) identify patterns of chemosensitivity for different tumor types, (3) establish
Exposure to acute hypoxia elicits a ventilatory response that is subject to various time-dependent phenomena, some of which occur during hypoxia (eg. hypoxic ventilatory decline) while others appear upon return to normoxia (eg. post-hypoxic frequency decline). In addition, memory components to the response exist, associated with repeated, acute hypoxic exposures (eg. progressive augmentation). Although central mechanisms, either downstream of afferent peripheral chemoreceptor input or through the direct effects of hypoxia on the brainstem, are sufficient to elicit these phenomena, little is known about the possible contribution of mechanisms arising from the carotid body. To investigate this further, we used an arterially perfused, en bloc rat carotid body preparation. Male rats (150-250g) were deeply anaesthetized in halothane (2 ml kg-1 within a 4 l chamber) until respiration ceased and animals failed to respond to a noxious paw pinch. Animals were then transected below the diaphragm, and the ...
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Yamaguchi, T.; Yamashita, J.; Ohmoto, M.; Aoudé, I.; Ogura, T.; Luo, W.; Bachmanov, A. A.; Lin, W.; Matsumoto, I.; Hirota, J. (2014) Skn-1a/Pou2f3 is required for the generation of Trpm5-expressing microvillus cells in the mouse main olfactory epithelium. BMC Neuroscience, 15, 13.. Bachmanov, A.A.; Bosak, N.P.; Lin, C.; Matsumoto, I.; Ohmoto, M.; Reed, D.R.; Nelson, T.M. (2013) Genetics of taste receptors. Current Pharmaceutical Design, (Electronic citation) PMID: 23886383. Matsumoto, I.; Ohmoto, M.; Abe, K. (2013) Functional diversification of taste cells in vertebrates. Seminars in Cell & Developmental Biology, 24, 210-214.. Matsumoto, I.(2013) Gustatory neural pathways from taste receptor cells revealed by genetic tracing. Bioscience, Biotechnology, Biochemisty, 77, 1359-1362.. Ohmoto, M.; Yamaguchi, T.; Yamashita, J.; Bachmanov, A.A.; Hirota, J.; Matsumoto, I. (2013) Pou2f3/Skn-1a is necessary for the generation or differentiation of solitary chemosensory cells in the anterior nasal cavity. ...
Blair Johnson arrived at the Department of Exercise and Nutrition Sciences after obtaining a PhD from Indiana University and serving as a postdoctoral research fellow at the Mayo Clinic. At Indiana University, he studied vascular function in response to various stressors such as food intake and exercise. During his time at the Mayo Clinic, he studied topics that centered on the reflex control of hemodynamics and metabolism. Specifically, he conducted projects that examined the physiological responses to blood loss in addition to studies that examined the role of the carotid body chemoreceptors in controlling ventilation during hyperthermia and blood glucose regulation during prolonged aerobic exercise. His current research interests are based on his previous work at Mayo and include physiological responses to carotid body stimulation as well as hemodynamic responses to simulated blood loss. ...
Hypoxic inhibition of K+ channels in type I cells is believed to be of central importance in carotid body chemotransduction. We have recently suggested that hypoxic channel inhibition is mediated by AMP-activated protein kinase (AMPK). Here, we have further explored the modulation by AMPK of recombinant K+ channels (expressed in HEK293 cells) whose native counterparts are considered O2-sensitive in the rat carotid body. Inhibition of maxiK channels by AMPK activation with AICAR was found to be independent of [Ca2+]i and occurred regardless of whether the α subunit was co-expressed with an auxiliary β subunit. All effects of AICAR were fully reversed by the AMPK inhibitor compound C. MaxiK channels were also inhibited by the novel AMPK activator A-769662 and by intracellular dialysis with the constitutively active, truncated AMPK mutant, T172D. The molecular identity of the O2-sensitive leak K+ conductance in rat type I cells remains unclear, but shares similarities with TASK-1 and TASK-3. Recombinant
1. Cardiac natriuretic peptides act on cardiopulmonary chemoreceptor afferents to enhance the von Bezold-Jarisch reflex (BJR). Activity of the natriuretic peptide particulate guanylyl cyclase receptor is essential for full expression of the BJR. Whether natriuretic peptides act directly on cardiac afferents or they require another intermediate factor(s) for their effects on the BJR is unknown. Endogenous candidates tested as possible intermediates in the present study were prostanoids and nitric oxide (NO), plausible endogenous chemical mediators of cardiac chemoreflex activity. 2. Dose-dependent BJR bradycardia was evoked by the 5-HT(3) receptor agonist, phenylbiguanide (range 5-89 μg/kg), in conscious instrumented adult sheep (n = 6). The influence of B-type natriuretic peptide (BNP; the most potent of the natriuretic peptides) on the BJR was assessed before and after blockade of prostanoids (using indomethacin, 1 mg/kg per h i.v.) or nitric oxide (using N-nitro-l-arginine (NOLA), 3 mg/kg ...

Abstract 956: Acid-Sensing Ion Channels (ASICs) Contribute to Transduction of Extracellular Acidosis in Rat Carotid Body Glomus...Abstract 956: Acid-Sensing Ion Channels (ASICs) Contribute to Transduction of Extracellular Acidosis in Rat Carotid Body Glomus...

The molecular mechanism of pH sensing by chemoreceptors is not clear, although it had been proposed to be mediated by a drop in ... Extracellular acidosis evoked transient inward currents in glomus cells that were evident at pH 7.0 and half-activated (pH 50) ... Recently, pH-sensitive ion channels have been described in glomus cells that respond directly to extracellular acidosis. In ... by recording the responses of glomus cells isolated from rat carotid body to rapid changes in extracellular pH using whole-cell ...
more infohttp://circ.ahajournals.org/content/116/Suppl_16/II_189.1

Peripheral chemoreceptor inputs to medullary inspiratory and postinspiratory neurons of cats<...Peripheral chemoreceptor inputs to medullary inspiratory and postinspiratory neurons of cats<...

... may then be considered in the context of this direct interaction as well as the network interactions of the various cells. ... Peripheral chemoreceptor inputs to medullary inspiratory and postinspiratory neurons of cats. Edward E. Lawson, Diethelm W. ... Peripheral chemoreceptor inputs to medullary inspiratory and postinspiratory neurons of cats. / Lawson, Edward E.; Richter, ... Peripheral chemoreceptors were activated by injecting CO2 saturated 1 N bicarbonate solution into the lingual artery or by ...
more infohttps://jhu.pure.elsevier.com/en/publications/peripheral-chemoreceptor-inputs-to-medullary-inspiratory-and-post-3

David D. Kline, PhDDavid D. Kline, PhD

This can happen during high altitude assent or disease states such as sleep apnea by activation of the chemoreceptor reflex. ... Expression of Group I metabotropic glutamate receptors on phenotypically different cells within the nucleus of the solitary ... Chronic intermittent hypoxia enhances carotid body chemoreceptor response to low oxygen. Adv Exp Med Biol. 2001;499:33-8. ... This includes changes in neurotransmitter release from presynaptic chemoreceptor afferent neurons as well as postsynaptic ...
more infohttps://biomed.missouri.edu/david-d-kline-phd/

Solitary chemoreceptor cells in the nasal cavity serve as sentinels of respiration | PNASSolitary chemoreceptor cells in the nasal cavity serve as sentinels of respiration | PNAS

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 ...
more infohttp://www.pnas.org/content/100/15/8981

Oxygen sensitivity of mitochondrial function in rat arterial chemoreceptor cells. - CLAHRCOxygen sensitivity of mitochondrial function in rat arterial chemoreceptor cells. - CLAHRC

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 ...
more infohttps://www.clahrc-oxford.nihr.ac.uk/publications/401957

Caltech Scientists Get Detailed Glimpse of Chemoreceptor Architecture in Bacterial Cells | CaltechCaltech Scientists Get Detailed Glimpse of Chemoreceptor Architecture in Bacterial Cells | Caltech

... 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 ...
more infohttp://www.caltech.edu/news/caltech-scientists-get-detailed-glimpse-chemoreceptor-architecture-bacterial-cells-1564

UVaDOC:  Viral Gene Transfer of Dominant-Negative Kv4 Construct Suppresses an O2-Sensitive K+  Current in Chemoreceptor CellsUVaDOC: Viral Gene Transfer of Dominant-Negative Kv4 Construct Suppresses an O2-Sensitive K+ Current in Chemoreceptor Cells

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 ...
more infohttp://uvadoc.uva.es/handle/10324/25950

Scientists get detailed glimpse of chemoreceptor architecture in bacterial cellsScientists get detailed glimpse of chemoreceptor architecture in bacterial cells

... 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 ...
more infohttps://phys.org/news/2009-09-scientists-glimpse-chemoreceptor-architecture-bacterial.html

Characterization of the chemosensitive re... & related info | MendeleyCharacterization of the chemosensitive re... & related info | Mendeley

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 ...
more infohttps://www.mendeley.com/research-papers/characterization-chemosensitive-response-individual-solitary-complex-neurons-adult-rats/

Primary effects of carotid chemoreceptor stimulation on gracilis muscle and renal blood flow and renal function in dogs.Primary effects of carotid chemoreceptor stimulation on gracilis muscle and renal blood flow and renal function in dogs.

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 +/- ...
more infohttp://www.biomedsearch.com/nih/Primary-effects-carotid-chemoreceptor-stimulation/1484369.html

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...

... 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 ...
more infohttp://embomolmed.embopress.org/content/6/12/1577

Peripheral chemoreceptor function after carbonic anhydrase inhibition during moderate-intensity exercise.Peripheral chemoreceptor function after carbonic anhydrase inhibition during moderate-intensity exercise.

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 ...
more infohttp://www.biomedsearch.com/nih/Peripheral-chemoreceptor-function-after-carbonic/10233116.html

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...

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 ...
more infohttps://idus.us.es/xmlui/handle/11441/64426

Cholinergic chemosensory cells in the trachea regulate breathingCholinergic chemosensory cells in the trachea regulate breathing

chemoreceptor cells; Choline O-Acetyltransferase; green fluorescent protein; heterotrimeric GTP-Binding proteins; reverse ... Morphologically similar cells in the nose have been identified as solitary chemosensory cells responding to taste stimuli and ... In the epithelium of the lower airways, a cell type of unknown function has been termed "brush cell" because of a distinctive ... Cholinergic chemosensory cells in the trachea regulate breathing. : Krasteva, G.; Canning, B.J.; Hartmann, P.; Veres, T.Z.; ...
more infohttp://publica.fraunhofer.de/dokumente/N-189831.html

Acute Cardiovascular and Sympathetic Effects of Nicotine Replacement Therapy | HypertensionAcute Cardiovascular and Sympathetic Effects of Nicotine Replacement Therapy | Hypertension

Excitatory nicotinic receptors are present on peripheral chemoreceptor cells. Chemoreceptors located in the carotid and aortic ... We did not expect these results, because glomus chemoreceptor cells contain excitatory nicotinic receptors.18-20 However, 2 ... Interaction of baroreceptor and chemoreceptor reflexes. Modulation of the chemoreceptor reflex by changes in baroreceptor ... Evidence for two types of nicotinic receptors in the cat carotid body chemoreceptor cells. Brain Res. 1997; 754: 298-302. ...
more infohttp://hyper.ahajournals.org/content/47/6/1162

Explore the British Library Search - Christopher SantosExplore the British Library Search - Christopher Santos

Chemoreceptor Cells (1) * Caribbean Area. fast (1) * Artificial intelligence. bicssc (1) * Engineering. fast (1) ... Arterial chemoreceptors : new directions and translational perspectives / Estelle B. Gauda, Maria Emilia Monteiro, Nanduri ...
more infohttp://explore.bl.uk/primo_library/libweb/action/search.do?ct=facet&fctN=facet_genre&fctV=Conference+papers+and+proceedings&rfnGrp=1&rfnGrpCounter=1&mode=Basic&vid=BLVU1&tab=local_tab&indx=1&fn=search&dscnt=0&vl

Explore the British Library Search - Christopher SantosExplore the British Library Search - Christopher Santos

Chemoreceptor Cells (1) * Carotid Body (1) * Myoclonic Epilepsies, Progressive (1) * Toxicology (1) ... Arterial chemoreceptors : new directions and translational perspectives / Estelle B. Gauda, Maria Emilia Monteiro, Nanduri ...
more infohttp://explore.bl.uk/primo_library/libweb/action/search.do?ct=facet&fctN=facet_genre&fctV=Electronic+books&rfnGrp=2&rfnGrpCounter=2&rfnGrpCounter=1&fn=search&indx=1&dscnt=0&vid=BLVU1&fctV=Springer&mode=Basic&ct=facet&rfnGrp=1&tab=local_tab&fctN=facet_local1&vl

human respiratory system - Chemoreceptors | physiology | Britannica.comhuman respiratory system - Chemoreceptors | physiology | Britannica.com

There are two kinds of respiratory chemoreceptors: arterial chemoreceptors, which monitor and respond to changes in the partial ... One way in which breathing is controlled is through feedback by chemoreceptors. ... pressure of oxygen and carbon dioxide in the arterial blood, and central chemoreceptors in... ... The type I cells are arranged in groups and are surrounded by type II cells. The type II cells are generally not thought to ...
more infohttps://www.britannica.com/science/human-respiratory-system/Chemoreceptors

Chemoreceptors in the Gut - PubMedChemoreceptors in the Gut - PubMed

The different cells of the gut epithelium are … ... Chemoreceptors in the Gut S Steensels et al. Annu Rev Physiol. ... Expression Patterns of L-amino Acid Receptors in the Murine STC-1 Enteroendocrine Cell Line H Wang et al. Cell Tissue Res 378 ( ... Enteroendocrine Cells: A Site of Taste in Gastrointestinal Chemosensing C Sternini et al. Curr Opin Endocrinol Diabetes Obes ... The different cells of the gut epithelium are therefore equipped with a subtle chemosensory system that communicates the ...
more infohttps://pubmed.ncbi.nlm.nih.gov/29029594/

Field studies on chemically mediated behavior in land hermit crabs: Volatile and nonvolatile odors | SpringerLinkField studies on chemically mediated behavior in land hermit crabs: Volatile and nonvolatile odors | SpringerLink

Narrow-spectrum chemoreceptor cells in the walking legs of the lobsterHomarus americanus: Taste specialists,J. Comp. Physiol. ...
more infohttps://link.springer.com/article/10.1007/BF01012347

JCI -
T2R38 taste receptor polymorphisms underlie susceptibility to upper respiratory infectionJCI - T2R38 taste receptor polymorphisms underlie susceptibility to upper respiratory infection

Nasal solitary chemoreceptor cell responses to bitter and trigeminal stimulants in vitro. J Neurophysiol. 2008;99(6):2929-2937. ... Cells were then trypsinized and seeded on porous polyester membranes (6∼7 × 104 cells per membrane) in cell culture inserts ( ... cells were seeded onto 96-well plates coated with poly-lysine at 40,000 cells per well. Cells were transfected with either ... Then the cells were washed 3 times with HBSS and left in 50 μl HBSS. The dye-loaded transfected cells in plates were placed ...
more infohttps://www.jci.org/articles/view/64240

Neurobiology and Cell Physiology of Chemoreception | Springer for Research & DevelopmentNeurobiology and Cell Physiology of Chemoreception | Springer for Research & Development

... and the corresponding receptors of chemoreceptor cells; and systemic analysis of reflex pathways involving chemoreceptor cells ... Peptide biology cell cell membrane cell physiology cells cognition membrane neurobiology physiology receptor ... Effects of Hypoxia on Cultured Chemoreceptors of the Rat Carotid Body: DNA Synthesis and Mitotic Activity in Glomus Cells ... Effects of Cell-Free Perfusion and Almitrine Bismesylate on the Ultrastructure of Type-I Cell Mitochondria in the Cat Carotid ...
more infohttps://rd.springer.com/book/10.1007%2F978-1-4615-2966-8

Guya D. Marconi - PubMed - NCBIGuya D. Marconi - PubMed - NCBI

Coexpression of Galanin and Nestin in the Chemoreceptor Cells of the Human Carotid Body. ... Chitlac-coated Thermosets Enhance Osteogenesis and Angiogenesis in a Co-culture of Dental Pulp Stem Cells and Endothelial Cells ... hBfl-1/hNOXA Interaction Studies Provide New Insights on the Role of Bfl-1 in Cancer Cell Resistance and for the Design of ...
more infohttps://www.ncbi.nlm.nih.gov/pubmed/?cmd=Search&term=Guya%20%20D.%20Marconi

Solitary chemosensory cells - WikipediaSolitary chemosensory cells - Wikipedia

Solitary chemosensory cells (SCCs) (also called solitary chemoreceptor cells) are isolated elements located in epithelia of the ... Whitear M. Solitary chemoreceptor cells. In: Chemoreception in fishes. Hara T.J. (Ed) Chapman and Hall New York 1992; pp. 103- ... Identification of the taste cell G-protein alpha-gustducin in brush cells of the rat pancreatic duct system. Histochem Cell ... Solitary chemoreceptor cells in the nasal cavity serve as sentinels of respiration. Proc Natl Acad Sci USA 2003; 100: 8981-86. ...
more infohttps://en.wikipedia.org/wiki/Solitary_chemosensory_cells

Pheochromocytoma and paraganglioma: genotype versus anatomic location as determinants of tumor phenotype | SpringerLinkPheochromocytoma and paraganglioma: genotype versus anatomic location as determinants of tumor phenotype | SpringerLink

Buckler KJ, Turner PJ (2013) Oxygen sensitivity of mitochondrial function in rat arterial chemoreceptor cells. J Physiol 591: ... An O2-sensitive glomus cell-stem cell synapse induces carotid body growth in chronic hypoxia. Cell 156:291-303PubMedCrossRef ... Tischler AS (2002) Chromaffin cells as models of endocrine cells and neurons. Ann N Y Acad Sci 971:366-370PubMedCrossRefGoogle ... Oxygen sensing by arterial chemoreceptors depends on mitochondrial complex I signaling. Cell Metab 22:825-837PubMedCrossRef ...
more infohttps://link.springer.com/article/10.1007%2Fs00441-017-2760-3
  • These chemosensory cells express T2R "bitter-taste" receptors and α-gustducin, a G protein involved in chemosensory transduction. (pnas.org)
  • 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)
  • 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)
  • 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)
  • 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)
  • Humans and most higher animals have two principal classes of chemoreceptors: taste (gustatory receptors), and smell (olfactory receptors). (encyclopedia.com)
  • Neurons, or nerve cells, serve as primary receptors. (encyclopedia.com)
  • 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)
  • 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)
  • 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)
  • The different cells of the gut epithelium are therefore equipped with a subtle chemosensory system that communicates the sensory information to several effector systems involved in the regulation of appetite, immune responses, and gastrointestinal motility. (nih.gov)
  • 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)
  • This identifies brush cells as cholinergic sensors of the chemical co mposition of the lower airway luminal microenvironment that are directly linked to the regulation of respiration. (fraunhofer.de)
  • 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)
  • 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)
  • Contrary to generally held beliefs Vhl is not a tumor suppressor gene in all cells. (embopress.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)
  • Recognition of factors that predispose to chromosomal losses, or amplify sub-threshold molecular alterations towards tumorigenic events in different (chromaffin) cell types, may facilitate the leap from developing targeted therapies towards establishment of tumor preventative measures. (springer.com)
  • Clusters of tumor cells (type I cells interspersed with type II cells), called zellballen, are surrounded by a dense network of capillary caliber blood vessels. (medscape.com)
  • To probe sient outward, O2-sensitive, K current of rabbit CB chemore- the molecular identity of this current, we have used dominant- negative constructs to block the expression of functional Kv channels of the Shaker (Kv1.xDN) or the Shal (Kv4.xDN) subfam- ceptor cells and that this current contributes to the cell depolarization in response to low pO2. (uva.es)
  • This depolarization causes voltage-gated Ca2+ channels to open, and for extracellular Ca2+ to flow down its concentration gradient into the cell causing the intracellular Ca2+ concentration to greatly increase. (wikipedia.org)
  • The organs of taste are the taste buds, bundles of slender cells with hairlike branches that are packed together in groups that form the projections called papillae at various places on the tongue. (thefreedictionary.com)
  • Most sensory systems use specialized sensory cells that link stimuli in the outside world to the nervous system. (pnas.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)
  • 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)
  • Höfer D, Drenckhahn D. Identification of the taste cell G-protein alpha-gustducin in brush cells of the rat pancreatic duct system. (wikipedia.org)
  • Chitlac-coated Thermosets Enhance Osteogenesis and Angiogenesis in a Co-culture of Dental Pulp Stem Cells and Endothelial Cells. (nih.gov)
  • Once the Ca2+ is inside the cell, it binds to the vesicle release machinery and facilitates binding of the t-snare complex on the vesicle to the s-snare complex on the NEC cell membrane which initiates the release of neurotransmitters into the synaptic cleft. (wikipedia.org)
  • 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)
  • Instead of tumorigenesis, Vhl inactivation in rodent catecholaminergic cells in vivo causes atrophy of the adrenal medulla, carotid body (CB) and sympathetic ganglia. (embopress.org)
  • Vhl‐deficiency in mouse sympathoadrenal cells does not result in the appearance of tumors. (embopress.org)
  • Höfer D, Puschel B, Drenckhahn D. Taste receptor-like cells in the rat gut identified by expression of α-gustducin. (wikipedia.org)