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We know that a painful stimulus activates a complex afferent system, the organisation and integration centres of which are only now being partly elucidated. We can accept the view of Bard and Mountcastle (1948) according to which the neocortex, the cingulate cortex, the amygdaloid nucleus and the pyriform lobe correspond to zones of the inhibition of pain and anger reactions. Their influence would be transmitted as far down as the brainstem by way of a circuit similar to the amygdaloid pathway. They suggest the presence, in addition, of a direct extra-amygdaloid pathway via which the neocortex might exert a facilitatory influence on the mesencephalic centres ...
Distension of the main pulmonary artery and its bifurcation are known to result in a reflex vasoconstriction and increased respiratory drive; however, these responses are observed at abnormally high distending pressures. In this study we recorded afferent activity from pulmonary arterial baroreceptors to investigate their stimulus-response characteristics and to determine whether they are influenced by physiological changes in intrathoracic pressure. In chloralose-anaesthetized dogs, a cardiopulmonary bypass was established, the pulmonary trunk and its main branches were vascularly isolated and perfused with venous blood at pulstatile pressures designed to simulate the normal pulmonary arterial pressure waveform. Afferent slips of a cervical vagus were dissected and nerve fibres identified that displayed discharge patterns with characteristics expected from pulmonary arterial baroreceptors. Recordings were obtained with (a) chest open (b) chest closed and resealed, and (c) with phasic negative ...
This is a list of medical mnemonics categorized and alphabetized. ABC - Airway, Breathing and Circulation AEIOU-TIPS - causes of altered mental status APGAR - a backronym for Appearance, Pulse, Grimace, Activity, Respiration (used to assess newborn babies) ASHICE - Age, Sex, History, Injuries/illness, Condition, ETA/extra information FAST - Face, Arms, Speech, Time - stroke symptoms Hs and Ts - causes of cardiac arrest Is Path Warm? - suicide risk factors OPQRST - Onset, Provocation, Quality, Region, Severity, Time - symptom checklist RICE - Rest, Ice, Compression, Elevation - for sprains and bruises RNCHAMPS - mnemonic for the types of shock RPM-30-2-Can Do - mnemonic for START triage criteria SOCRATES - mnemonic used to evaluate characteristics of pain SOAP, a technique for writing medical records SLUDGE - Salivation, Lacrimation, Urination, Defecation, Gastric upset, and Emesis (effects of nerve agent or organophosphate poisoning) Afferent connection arrives and an efferent connection exits. ...
My research interests are to investigate the mechanisms of cardiac sympathetic afferents activation and the associated central nervous system (CNS) reflex processing as well as modulation of electroacupuncture (EA) on CNS regulation of cardiovascular function. Studies of cardiac afferents activation are funded by a NIH grant (serve as CO-PI ). In these studies, I am investigating the mechanisms of activation and sensitization of cardiac afferents induced by multiple ischemic mediators including endothelins, thromboxane A2, 5-hydroxytryptamine (5-HT), histamine, lactic acid (protons), reactive oxygen species and bradykinin (BK), which stimulate and/or sensitize cardiac spinal afferents during ischaemia and reperfusion in an interactive and multifactorial fashion. I am also studying the mechanisms underlying CNS reflex processing evoked by ischemic metabolites during myocardial ischemia ...
Long after a cut peripheral nerve reinnervates muscle and restores force production in adult cats, the muscle does not respond reflexively to stretch. Motivated by the likelihood that stretch areflexia is related to problems with sensing and controlling limb position after peripheral neuropathies, we sought to determine the underlying mechanism. Electrophysiological and morphological measurements were made in anesthetized rats having one of the nerves to the triceps surae muscles either untreated or cut and immediately rejoined surgically many months earlier. First, it was established that reinnervated muscles failed to generate stretch reflexes, extending observations of areflexia to a second species. Next, multiple elements in the sensorimotor circuit of the stretch reflex were examined in both the PNS and CNS. Encoding of muscle stretch by regenerated proprioceptive afferents was remarkably similar to normal, although we observed some expected abnormalities, e.g., increased length threshold. However,
To the Editor:. We read with interest the recent article by Zhang et al.1 The authors described secondary degeneration in remote regions after experimental cerebral ischemia, which could provide a target for stroke management. We completely agree that this is an appealing approach. However, the underlying pathology may be different in ischemic rodents and patients with stroke.. Remote areas such as the thalamus connected to the cortical infarct are affected because of delayed retrograde degeneration of afferent connections. This is associated with extensive and complex pathology including inflammatory reactions, β-amyloid (Aβ) accumulation, calcification, and angiogenesis in rats subjected to middle cerebral artery occlusion.2 The Aβ deposition is particularly robust after an ischemic insult, which starts as a diffuse aggregation and over time transforms into dense plaque-like deposits together with calcium in the ventroposterior medial and ventroposterior lateral nuclei.3,4 Altered ...
The cerebellar cortex comprises a few cell types and two main afferent systems arranged in a stereotyped synaptic pattern that is repeated monotonously throughout. The regularity of the laminated...
There are many other models that can simulate individual results presented here (Douglas and Martin, 1991; Ben-Yishai et al., 1995; Somers et al., 1995; Carandini and Ringach, 1997; Troyer et al., 1998; Adorján et al., 1999; Dragoi and Sur, 2000; Stetter et al., 2000) (for review, see Ferster and Miller, 2000; Seriès et al., 2003), and many of these models employ mechanisms similar to those used by PC/BC. However, the PC/BC model differs from these previous models in providing a computational explanation for the behavior of V1 neurons as well as providing a unified account of a number of processes that are currently considered, and modeled, in isolation. The model also makes testable predictions that are described in the supplemental material (available at www.jneurosci.org).. Consistent with previous models and neurophysiological results (Pei et al., 1994; Sompolinsky and Shapley, 1997; Xing et al., 2005), orientation tuning in the PC/BC model results from broadly tuned afferent excitation ...
Gastrointestinal (GI) vagal afferents are a key mediatory of food intake. Through a balance of responses to chemical and mechanical stimuli food intake can be tightly controlled via the ascending satiety signals initiated in the GI tract. However, va
The interneuronally mediated reflex actions evoked by electrical stimulation of group II muscle afferents in low spinal cats have been reinvestigated with intracellular recording from motoneurones to
In the Golli-tau-eGFP (GTE) transgenic mouse the reporter gene expression is largely confined to the layer of subplate neurons (SPn), providing an opportunity to study their intracortical and extracortical projections. In this study, we examined the thalamic afferents and layer IV neuron patterning in relation to the SPn neurites in the developing barrel cortex in GTE mouse at ages embryonic day 17 (E17) to postnatal day 14 (P14). Serotonin transporter immunohistochemistry or cytochrome oxydase histochemistry was used to reveal thalamic afferent patterning. Bizbenzimide staining identified the developing cytoarchitecture in coronal and tangential sections of GTE brains. Enhanced green fluorescent protein (GFP)-labelled neurites and thalamic afferents were both initially diffusely present in layer IV but by P4-P6 both assumed the characteristic periphery-related pattern and became restricted to the barrel hollows. This pattern gradually changed and by P10 the GFP-labelled neurites largely accumulated at
Sigma-Aldrich offers abstracts and full-text articles by [H-J Sun, H Zhou, X-M Feng, Q Gao, L Ding, C-S Tang, G-Q Zhu, Y-B Zhou].
The pain system involves a set of ascending pathways that convey nociceptive information from peripheral nociceptors via neuronal tracts of the spinal cord to the higher levels of the CNS.
TY - CHAP. T1 - Organization of Prefrontal-Striatal Connections. AU - Groenewegen, HJ. AU - Wouterlood, FG. AU - Uylings, HBM. PY - 2017. Y1 - 2017. N2 - This chapter describes the organization of the prefrontal-striatal projections. There exists a topographical relationship in these projections, such that sensorimotor cortices project to the dorsolateral part of the striatum, associative cortical regions to more ventral and medial regions, and the limbic cortical areas to the most ventromedial striatal areas. Whereas the parallel, segregated nature of these projections has been emphasized for a long time, more recent studies, taking into account the so-called focal and diffuse types of termination of cortical afferents in the striatum, show that there is considerable overlap between projections from different prefrontal cortical projection areas in the striatum. This allows for specific integration of information. Further, the relationship of the prefrontal cortex with the striatal ...
own identity that could bring you straight to the depressiontervistati. Sildenafil, Is marketed with dosages fromfixed and dose escalation studies (23) . In responders,resistance, it is stressed, âincreased production of endogenous genetic or ethnic-racial, comorbilità , the weight, the riskbeautiful 2).why increase the dimen-These potentially modifiable risk factors and causespeptide) and nitric oxide (NO). Is 3. the afferent pathways and byErectile dysfunction and diabetesGLP1 allows you to reach ambitious targets in safety and feel. All participants were subjected to the relief of the parameters cialis 20mg.. There are conditions that facilitate the1. Gebski V, Marschner I, Keech AC. Specifying objectives andza how much is deleterious on the-is not diagnosed. Cardiovascular disease (but-rea (29±5; 30±5; 29±4 kg/m2 in the three groups, respectively). âglycated hemoglobin, have not shown differences signi-and physical fitness in men aged 40â 75 years. Int J Impot a Mediterranean ...
t= [0:0.1:2*pi]; Inb1.time = t; Inb1.signals.values(:,1) = 2*sin(t); Inb1.signals.values(:,2) = 2*cos(t); t= [0:0.2:2*pi]; Inb2.time = t; Inb2.signals.values(:,1) = sin(2*t); t= [0:0.1:2*pi]; Inb3.time = t; Inb3.signals.values(:,1) = 0.5*sin(3*t); Inb3.signals.values(:,2) = 0.5*cos(3*t); save rsim_i_multi_struct.mat Inb1; save rsim_i_multi_struct.mat Inb2 -append; save rsim_i_multi_struct.mat Inb3 -append; disp(rsim_i_multi_struct.mat contains three variables Inb1\Inb2\Inb3); disp(in struct format. Note that command save -append option must be); disp(used to generate the MAT-file to preserve the order of the); disp(variables in the MAT-file generated. The command:) disp(save rsim_i_multi_struct.mat Inb1 Inb2 Inb3 might not preserve); disp(the order of the variables in the MAT-file and you should not use it); disp(to generate the MAT-file. ...
Im currently cutting for the next two months and need some input on what natural bulking stack would help me achieve the best goals possible. I was
The major unit of functionality of the lateral line is the neuromast. The neuromast is a mechanoreceptive organ which allows the sensing of mechanical changes in water. There are two main varieties of neuromasts located in animals, canal neuromasts and superficial or freestanding neuromasts. Superficial neuromasts are located externally on the surface of the body, while canal neuromasts are located along the lateral lines in subdermal, fluid filled canals. Each neuromast consists of receptive hair cells whose tips are covered by a flexible and jellylike cupula. Hair cells typically possess both glutamatergic afferent connections and cholinergic efferent connections.[12] The receptive hair cells are modified epithelial cells and typically possess bundles of 40-50 microvilli "hairs" which function as the mechanoreceptors.[13] These bundles are organized in rough "staircases" of hairs of increasing length order.[14] This use of mechanosensitive hairs is homologous to the functioning of hair cells ...
TY - JOUR. T1 - Reduced short- and long-latency afferent inhibition following acute muscle pain. T2 - A potential role in the recovery of motor output. AU - Burns, Emma. AU - Chipchase, Lucinda Sian. AU - Schabrun, Siobhan May. N1 - © 2016 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: [email protected] PY - 2016/7/1. Y1 - 2016/7/1. N2 - OBJECTIVE: . Corticomotor output is reduced in response to acute muscle pain, yet the mechanisms that underpin this effect remain unclear. Here the authors investigate the effect of acute muscle pain on short-latency afferent inhibition, long-latency afferent inhibition, and long-interval intra-cortical inhibition to determine whether these mechanisms could plausibly contribute to reduced motor output in pain.DESIGN: . Observational same subject pre-post test design.SETTING: . Neurophysiology research laboratory.SUBJECTS: . Healthy, right-handed human volunteers (n = 22, 9 male; mean age ± standard ...
The laterodorsal nucleus (LDN) of the thalamus provides a prominent afferent projection to the postsubiculum (dorsal presubiculum). To characterize synaptic transmission in this pathway, we placed stimulating electrodes in the LDN and recorded fEPSPs elicited in the postsubiculum of urethane-anesthetized rats. LDN stimulation elicited a source-sink dipole between the deep and superficial layers of the postsubiculum, respectively, consistent with anatomical evidence for the termination of thalamic afferents in the superficial layers of the structure, and the existence of deep layer neurons with apical dendrites extending into these layers. Postsubicular fEPSPs were typically 0.5-1.0 mV in amplitude, with a peak latency of approximately 6 ms. Consistent with anatomical observations, the short onset latency of fEPSPs elicited by LDN stimulation, and their ability to follow a 60-Hz train of stimulation, indicate that the projection is monosynaptic. Paired-pulse stimulation revealed pronounced ...
Renal denervation decreases arterial pressure (AP) in hypertensive rats and humans. This procedure destroys both afferent and efferent nerves. Several investigators have proposed that renal afferent nerves contribute to the elevated AP. We developed a procedure to selectively remove renal afferent nerves with capsaicin (1-100 mM) both topically on the nerve and in the renal pelvis. We examined the effects of renal deafferentation on the development of genetic and renal hypertension. We studied spontaneously hypertensive rats (SHR), and a model of renal hypertension, two kidney-one clip (2K1C) in Sprague-Dawley rats. SHR were treated at 3-4 weeks of age with capsaicin. Mean arterial pressure was recorded by tail cuff through 16 weeks of age. On week 17, rats were cannulated, allowed 3 days to recover then had their AP measured directly for 3 days (3 hrs/day). Rats with renal deafferentation (n=11) had lower arterial pressure weeks 9-16 (average reduction AP=10.1±1.4 mmHg, ANOVA, p=0.0049) ...
In: Kultas-Ilinsky K, Ilinsky IA, editors. Basal Ganglia and Thalamus in Health and Movement Disorders. New York: Kluwer Academic Plenum Press, pp. 61-67, 2001 Abstract Knowledge of the organization and connections of the basal ganglia has greatly advanced in recent years, and, concurrently, und ...
Vision systems satisfying the single viewpoint constraint are called central projection systems. The perspective camera is an example of a central projection system. The mapping of points in the scene into points in the image is linear in homogeneous coordinates, and can be described by a 3 × 4 projection matrix P (pin-hole model). Perspective projection can be modeled by intersecting a plane with a pencil of lines going through the scene points and the projection center O. There are central projection systems whose geometry can not be described using the conventional pin-hole model. Mt is composed of two lines m and l lying on the projective plane ℘2 . In this case the conic is said to be degenerate, the 3 ×3 symmetric matrix Ω is rank 2, and Equation (15) becomes ⎤ ⎡ 1 0 0 0 0 0 ⎢0 2 0 0 0 0⎥ ⎥ ⎢ ⎢0 0 1 0 0 0⎥ t t ⎥. Γ(m, l) ⎢ Ω = ml + lm −→ ω = ⎢ (16) ⎥ ⎢0 0 0 2 0 0⎥ ⎣0 0 0 0 2 0⎦ 0 0 0 0 0 1 e D In a similar way a conic locus can be composed of a ...
Cortical spreading depression (CSD) is the likely cause of the migraine aura. CSD causes a signaling pathway between stressed neurons and trigeminal afferents via transient opening of neuronal Pannexin-1 (Panx1) mega-channels ...
Afferent fibers originating in nucleus of the tractus solitarius (NTS) project to both supra- and subdiaphragmatic viscera. Back ...
The present study demonstrates the TRPA1 was expressed in both bladder and DRG (L6-S1) and had a pronounced upregulation in DRG but more slight in mucosa in rat cystitis. The blockade of TRPA1 via intrathecal administration decreased afferent nerve activities and consequently attenuated detrusor overactivity markly. More recently, Tomonori et al. have shown that TRPA1 channel could improve afferent nerve activities of the rat bladder through both Aδ- and C-fibers pathway [16]. TRPA1 channels have been conducted in multiple-sensation modalities at present including mechanical, nociceptive, and thermal sensation in mammal [17-19].. However, the function of TRPA1 as nociceptor in the DRG innervating bladder is really quite controversial and further research is needed. We suppose the activation of TRPA1 receptors in DRG may lead to hyperalgesia, playing a role in enhanced impulse conduction and detrusor overactivity. We observed hematuria, severe submucosal edema, hemorrhage, ulceration, congestion ...
The present results replicate our previous finding that subdiaphragmatic vagal afferents are not necessary for the feeding-suppressive effects of intraperitoneal IL-1β and LPS and extend those findings to include another bacterial cell wall compound, MDP. Our functional test of complete subdiaphragmatic vagal deafferentation confirmed in both SDA and COM groups that low doses of CCK (4 μg/kg) failed to suppress food intake. Furthermore, these data reveal that neither splanchnic nor vagal subdiaphragmatic visceral afferents are necessary to mediate the hypophagia produced by intraperitoneal administration of IL-1β, LPS, or MDP, because combined subdiaphragmatic vagal deafferentation and celiac-superior mesenteric ganglionectomy failed to alter the ability of these compounds to suppress feeding.. The present finding that subdiaphragmatic vagal afferent fibers are not required for the hypophagic effect of intraperitoneal IL-1β, LPS, or MDP is consistent with results from other studies showing ...
title: The synaptic microcircuitry associated with primary afferent terminals in the interpolaris and caualis of trigeminal sensory nuclear complex, doi: 10.1016/j.brainres.2005.08.042, category: Article
We have examined the organization of muscle afferent projections to motoneurons in the lumbosacral spinal cord of chick embryos between stage 37, when muscle afferents first reach the motor nucleus, and stage 44, which is just before hatching. Connectivity between afferents and motoneurons was assessed by stimulating individual muscle nerves and recording the resulting motoneuron synaptic potentials intracellularly or electrotonically from other muscle nerves. Most of the recordings were made in the presence of DL-2-amino-5- phosphonovaleric acid (APV), picrotoxin, and strychnine to block long- latency excitatory and inhibitory pathways. Activation of muscle afferents evoked slow, positive potentials in muscle nerves but not in cutaneous nerves. These potentials were abolished in 0 mM Ca2+, 2mM Mn2+ solutions, indicating that they were generated by the action of chemical synapses. The muscle nerve recordings revealed a wide-spread pattern of excitatory connections between afferents and ...
This study has demonstrated that systemically administered CCK produces inhibition of a subpopulation of RVLM presympathetic neurons via a mechanism that is dependent on intact subdiaphragmatic vagal afferents and central NMDA receptors.. Interruption of vagal afferent traffic arising in subdiaphragmatic branches of the vagus was achieved by topical application of the local anesthetic lidocaine. It was expected that this treatment would abolish the neuronal responses to CCK but not PBG, because subdiaphragmatic vagal afferents are responsive to systemically administered CCK and PBG activates 5-HT3 receptors located on cardiopulmonary vagal afferents (19, 21). This prediction proved correct because lidocaine application to the subdiaphragmatic vagi blocked the response to systemic CCK but not PBG. This finding also suggests that the lidocaine did not spread sufficiently to anesthetize cardiopulmonary vagal afferents. We (16) have previously observed that the inhibitory responses of RVLM ...
The cerebral cortex, which underlies higher brain functions, has undergone a large expansion in size during mammalian evolution, most notably in the primate lineage (Rakic, 1988; Caviness and Takahashi, 1995; Northcutt and Kaas, 1995; Rakic, 1995). Although many intrinsic and extrinsic factors may influence cortical size and cytoarchitecture, such as patterns of neuronal migration (Letinic et al., 2002; Kriegstein and Noctor, 2004; Bystron et al., 2006), thalamic afferents (Windrem and Finlay, 1991; Dehay et al., 2001) and the diversification of subventricular zone neural progenitors (Smart et al., 2002; Haubensak et al., 2004; Miyata et al., 2004; Noctor et al., 2004; Fish et al., 2008), an increase in neuron number during brain development and evolution is ultimately controlled by the number and modes of division of neural progenitors in the embryonic ventricular and subventricular zones (Götz and Huttner, 2005; Kriegstein et al., 2006; Fish et al., 2008).. According to the radial unit ...
The effects of excitatory amino acids on 22Na efflux rate in rat hippocampal slices were determined at various postnatal days and following removal of a major afferent system. Two weeks after a unilateral hippocampal aspiration, the 22Na efflux induc
Both cell types generic kamagra super 160mg without a prescription, in conjunction with enteric microbiota produce a variety of signalling molecules that can activate a number of receptors on extrinsic primary afferent neurons buy kamagra super 160 mg with visa. Therefore, endocrine, neuronal and immune signals are all integrated and are sent to specific brain regions and may alter cognition, mood and emotions. The stomach is predominantly governed by vago-vagal reflexes, thus signals arising from extrinsic and intrinsic neurons are relatively weak. In the intestines, intrinsic primary afferent neurons and enteric motorneurons are important for intestinal function afferents are much stronger in the intestine, which are reliant on these signals [17]. Inter- estingly, some of these intrinsic afferents are normally unresponsive to mechanical stimuli, and only become responsive during periods of inflammation [33]. These terminals contain chemosensitive receptors, which are responsive to the ...
Stimulating the vagus nerve supports that tempering effect, but it can also somewhat excite the part of the nervous system that stimulates the immune response, which is counterproductive if youre looking to calm it.. "Every circuit has a path coming from the brain and one going to the brain, and when you stimulate electrically, you usually have no control over which one you get. You usually get both." Patel said. These paths are often in the same nerve being stimulated.. The path leaving the brain and going toward other organs, called the efferent pathway, is the one to stimulate to temper the immune system and help relieve chronic inflammatory conditions. The one going to the brain, called the afferent pathway, if stimulated, leads eventually to the hypothalamus, a pea-sized region in the center of the brain. That triggers a chain of hormonal responses, eventually releasing cytokines, messaging molecules that promote inflammation.. "You get a heightened inflammatory response when you stimulate ...
We describe a computational model of the principal cell in the nucleus accumbens (NAcb), the medium spiny projection (MSP) neuron. The model neuron, constructed in NEURON, includes all of the known ionic currents in these cells and receives synaptic input from simulated spike trains via NMDA, AMPA, and GABAA receptors. ... results suggest that afferent information integration by the NAcb MSP cell may be compromised by pathology in which the NMDA current is altered or modulated, as has been proposed in both schizophrenia and addiction ...
We describe a computational model of the principal cell in the nucleus accumbens (NAcb), the medium spiny projection (MSP) neuron. The model neuron, constructed in NEURON, includes all of the known ionic currents in these cells and receives synaptic input from simulated spike trains via NMDA, AMPA, and GABAA receptors. ... results suggest that afferent information integration by the NAcb MSP cell may be compromised by pathology in which the NMDA current is altered or modulated, as has been proposed in both schizophrenia and addiction ...
It has been clear for almost two decades that cortical representations in adult animals are not fixed entities, but rather, are dynamic and are continuously modified by experience. The cortex can preferentially allocate area to represent the particular peripheral input sources that are proportionall …
The Estimates and Projections (E&P) database is the most extensive update available, covering a broad range of demographic characteristics for the current year, and 5-year projections. Variables include:. ...
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TY - JOUR. T1 - Modulation by serotonin of the neurons in rat nucleus raphe magnus in vitro. AU - Pan, Z. Z.. AU - Wessendorf, M. W.. AU - Williams, John. PY - 1993. Y1 - 1993. N2 - Nucleus raphe magnus contains a large population of raphe-spinal serotonergic neurons that are thought to be involved in descending control of pain transmission and the modulation of opioid analgesia. Intracellular recordings were made from nucleus raphe magnus neurons in the slice preparation. Cells were divided into two groups, primary and secondary cells, based on the action potential waveform and response to opioids, as reported previously. In some experiments, cells were filled with biocytin and 5-hydroxytryptamine-containing cells were identified immunohistochemically. Of the primary cells that were filled with biocytin, 93% stained for 5-hydroxytryptamine; 90% of biocytin-filled secondary cells were unlabeled for 5-hydroxytryptamine. Previous studies have shown that primary cells are disinhibited by opioids; ...
TY - JOUR. T1 - Cardiac vagal afferent stimulation by free radicals during ischaemia and reperfusion. AU - Schultz, Harold D.. AU - Ustinova, Elena E.. PY - 1996/1/1. Y1 - 1996/1/1. N2 - 1. Myocardial ischaemia and reperfusion can evoke excitation of cardiac vagal afferent nerve endings and activation of a cardiogenic depressor reflex (Bezold-Jarisch effect). We postulate that oxygen free radicals, which are well known to be produced during ischaemia and reperfusion, contribute to this excitation. 2. Activity from vagal afferent fibres in rats, whose endings were located in the walls of all four chambers of the heart, was recorded in response to topical application of pro-oxidant chemicals to the surface of the heart. Activity was also recorded from vagal afferent fibres, whose endings were located in the left ventricle, in response to occlusion of the left anterior coronary artery (LAC) for 30 min and subsequent reperfusion. A majority of the recorded fibres were classified as chemosensitive ...
Selective reduction in or augmentation of intrasplenic NO caused a respective increase or decrease in systemic blood pressure. The same doses of pharmacological agents were without effect when administered systemically. The increase in MAP in response to intrasplenic L-NMMA was abolished by interrupting either the splenic or the renal nerves. It was also inhibited by administration of the ACE inhibitor enalapril. On the basis of these results, we propose that the spleen participates in the regulation of blood pressure through a reflex pathway, whereby changes in splenic afferent nerve activity reflexly alter renal sympathetic control of renin release. The subsequent rise in circulating angiotensin II levels would act directly on the vasculature to raise total peripheral resistance. Angiotensin II could also alter central control of blood pressure by accessing the brain at the circumventricular organs.8. There is both structural and functional evidence to support the existence of such a reflex ...
NEUROANATOMY. General organization of the nervous system. Meningeal coverings and the ventricular system. The spinal cord: external and internal organization. The spinal nerves. The brain stem: external and internal organization. Main nuclei of the brain stem. The tectum. The reticular formation. The cranial nerves. The cerebellum: external and internal organization. Nuclei and cerebellar cortex. The diencephalon: thalamus, hypothalamus, basic facts on epithalamus and subthalamus. The telencephalon: external configuration. The cerebral cortex. The basal nuclei. Organization of the telencephalic white matter. Overview of the limbic system. The ippocampus. Cerebral specializations. Afferent systems. Overview of the different receptor types. Exteroceptive and proprioceptive sensory receptors. Ascending sensory pathways. The olfactory receptors and and the olfaction pathway. The gustatory receptors and the taste pathway. The eye and the visual system. The ear and the auditory and vestibular systems. ...
Stroke are the main causes of motor disability among adults and are expected to impose an increasing social and economic burden for our Country. The impact of stroke on patients is enormous, with negative ramifications on the persons participation in social, vocational, and recreational activities. It is the primary cause of long-term disability in these countries. At the present stage, it is well known that control of balance during upright standing depends upon the central integration of afferent information from vestibular, somatosensory (proprioceptive, tactile), and visual systems, which constitute a multilink neural network for the control of neck, hip, and ankle joints. More recently, it has been studied at the level of cerebral cortex; vestibular inputs would reach face/neck representation of primary somatosensory cortex and would be then integrated with visual and somatosensory inputs in intraparietal, posterior end of the insula and medial superior temporal cortices. Remarkably, ...
The word homeostasis is derived from the Greek hómos "similar" and histemi "standing still". It is used to describe a general concept of environmental stability that is maintained within living organisms. An example is body temperature in humans, which can be consistently observed around 37ºC (98.6ºF). The term and concept are attributed to American physiologist, Walter Bradford Cannon, around the turn of the twentieth century. At that time, the concept of homeostasis built upon French physiologist, Claude Bernards, use of milieu de lintérieur (the environment within) during the mid-nineteenth century to describe the stability and protection of internal organs and tissues by the blood.; ".... the blood constitutes an actual organic environment, an intermediary between the external environment and the (internal) living molecules, which cannot safely be brought into contact with their external environment ..." -An Introduction to the Study of Experimental Medicine. preface by L Henderson, ...
The whisking of a rats whisker is a classic example of "active sensing" - in other words, sensing that involves movement. Prof. Ehud Ahissar studies rat whisking in order to understand how mammals perceive through all types of active sensing; without the continuous movement of whiskers, fingertips or eyes, our perception of our surroundings would be lacking. (If you dont believe us, try feeling the texture of your shirt or desktop without moving your fingers. You cant stop your eyes - as you read this, your eyes are actually moving back and forth in tiny movements.). In the latest research in his lab, postdoctoral fellow Dr. Avner Wallach and Dr. Knarik Bagdasarian managed to decode the signal that is sent from the clump of nerve endings at the base of the whisker to the rats brain. They accomplished this by creating a machine-brain interface, the machine recreating the whisking muscles movement and intercepting the nerve endings signals.. The amazing thing the scientists realized is that ...