The Experts below are selected from a list of 258 Experts worldwide ranked by ideXlab platform
John C. Longhurst - One of the best experts on this subject based on the ideXlab platform.
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GABA in nucleus tractus solitarius participates in electroacupuncture modulation of cardiopulmonary bradycardia Reflex
American journal of physiology. Regulatory integrative and comparative physiology, 2014Co-Authors: Stephanie C. Tjen-a-looi, Zhi-ling Guo, John C. LonghurstAbstract:Phenylbiguanide (PBG) stimulates cardiopulmonary receptors and Cardiovascular Reflex responses, including decreases in blood pressure and heart rate mediated by the brain stem parasympathetic cardi...
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Serotonergic projection from nucleus raphe pallidus to rostral ventrolateral medulla modulates Cardiovascular Reflex responses during acupuncture.
Journal of applied physiology (Bethesda Md. : 1985), 2010Co-Authors: Ali R. Moazzami, Stephanie C. Tjen-a-looi, Zhi-ling Guo, John C. LonghurstAbstract:We have demonstrated that stimulation of somatic afferents during electroacupuncture (EA) inhibits sympathoexcitatory Cardiovascular rostral ventrolateral medulla (rVLM) neurons and Reflex responses. Furthermore, EA at P5-P6 acupoints over the median nerve on the forelimb activate serotonin (5-HT)-containing neurons in the nucleus raphe pallidus (NRP). The present study, therefore, examined the role of the NRP and its synaptic input to neurons in the rVLM during the modulatory influence of EA. Since serotonergic neurons in the NRP project to the rVLM, we hypothesized that the NRP facilitates EA inhibition of the Cardiovascular sympathoexcitatory Reflex response through activation of 5-HT1A receptors in the rVLM. Animals were anesthetized and ventilated, and heart rate and blood pressure were monitored. We then inserted microinjection and recording electrodes in the rVLM and NRP. Application of bradykinin (10 μg/ml) on the gallbladder every 10 min induced consistent excitatory Cardiovascular Reflex responses. Stimulation with EA at P5-P6 acupoints reduced the increase in blood pressure from 41 ± 4 to 22 ± 4 mmHg for more than 70 min. Inactivation of NRP with 50 nl of kainic acid (1 mM) reversed the EA-related inhibition of the Cardiovascular Reflex response. Similarly, blockade of 5-HT1A receptors with the antagonist WAY-100635 (1 mM, 75 nl) microinjected into the rVLM reversed the EA-evoked inhibition. In the absence of EA, NRP microinjection of dl-homocysteic acid (4 nM, 50 nl), to mimic EA, reduced the Cardiovascular and rVLM neuronal excitatory Reflex response during stimulation of the gallbladder and splanchnic nerve, respectively. Blockade of 5-HT1A receptors in the rVLM reversed the NRP dl-homocysteic acid inhibition of the Cardiovascular and neuronal Reflex responses. Thus activation of the NRP, through a mechanism involving serotonergic neurons and 5-HT1A receptors in the rVLM during somatic stimulation with EA, attenuates sympathoexcitatory Cardiovascular Reflexes.
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medulla modulates Cardiovascular Reflex responses
2009Co-Authors: Ali R. Moazzami, Stephanie C. Tjen-a-looi, Zhi-ling Guo, John C. LonghurstAbstract:projection from nucleus raphe pallidus to rostral ventrolatera
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Naloxone reverses inhibitory effect of electroacupuncture on sympathetic Cardiovascular Reflex responses.
The American journal of physiology, 1999Co-Authors: Dong M. Chao, Stephanie C. Tjen-a-looi, Lin L. Shen, Koullis F. Pitsillides, John C. LonghurstAbstract:Acupuncture and electroacupuncture (EA) have been used in traditional Chinese medicine to treat a wide range of diseases and conditions, including angina pectoris and myocardial infarction. In a fe...
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Cardiovascular Reflex responses to ischemia during occlusion of celiac and/or superior mesenteric arteries
American Journal of Physiology-Heart and Circulatory Physiology, 1997Co-Authors: Stephen V. Rendig, Premjit S. Chahal, John C. LonghurstAbstract:Global abdominal visceral ischemia leads to profound Cardiovascular Reflex adjustments. However, the separate contributions of the celiac artery and superior mesenteric artery (SMA) vascular beds to this Reflex are unknown. Accordingly, we compared the effects of single and combined occlusions of these vessels on blood pressure (BP) in anesthetized cats. Tissue mass and pH of selected organs, regional blood gases, pH, and lactate also were measured as potential contributing factors. Occlusion of the SMA or celiac artery produced significantly (P < 0.05) different increments in BP (30 +/- 4 vs. 18 +/- 4 mmHg, respectively). Combined occlusion of the two vessels augmented BP by 53 +/- 12 mmHg, a significantly greater increase than during celiac ligation. Venous lactate levels increased significantly during SMA, but not celiac, occlusion, and the decline in venous pH was significantly greater in the SMA than in the celiac vascular bed (-0.20 +/- 0.03 vs. -0.08 +/- 0.02 pH units, P < 0.05, respectively). The decline in tissue pH of SMA-perfused organs during SMA occlusion was significantly greater than in celiac-perfused organs during celiac occlusion. Conversely, tissue mass subserved by the celiac artery was significantly greater than that subserved by the SMA (182 +/- 27 vs. 131 +/- 17 g, respectively). These data suggest that the larger Cardiovascular Reflex produced by SMA occlusion compared with celiac occlusion may be related to a greater increase of lactic acid concentration in tissue supplied by the SMA. In addition, the large Reflex increase in BP produced by combined occlusion of these vessels is an additive effect, presumably related to larger organ mass and recruitment of more sensory nerve fibers.
Robert F Schmidt - One of the best experts on this subject based on the ideXlab platform.
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Cardiovascular Reflex control by afferent fibers from skeletal muscle receptors
Comprehensive Physiology, 2011Co-Authors: Jere H Mitchell, Robert F SchmidtAbstract:The sections in this article are: 1 Afferent Fibers from Skeletal Muscle and Their Receptors 1.1 Composition of Muscle Nerves 1.2 Muscle Spindles and Golgi Tendon Organs 1.3 Receptive Properties of Group III and Group IV Afferent Fibers 2 Central Pathways for Cardiovascular Reflexes from Skeletal Muscle Receptors 2.1 Spinal Termination of Primary Muscle Afferents 2.2 Central Pathways Arising From Myelinated Primary Muscle Afferents 2.3 Central Pathways Arising From Unmyelinated Primary Muscle Afferents 2.4 Ascending and Descending Spinal Pathways Involved in Cardiovascular Reflex Control From Skeletal Muscle 3 Organization of Efferent Outflow in Pre- and Postganglionic Neurons 4 Cardiovascular Responses from Skeletal Muscle Receptors 4.1 Effect of Activation of Afferent Fibers 4.2 Effect of Induced Muscular Contraction (Simulated Exercise) 5 Interaction of Muscle Afferents with Other Cardiovascular Reflexes 5.1 Arterial Baroreceptors 5.2 Cardiopulmonary Vagal Afferents 6 Role of Skeletal Muscle Afferents in Cardiovascular Response to Exercise in Humans 6.1 Dynamic and Static Exercise 6.2 Central Control (Central Command) 6.3 Peripheral Control 6.4 Integration of Neural Control Mechanisms During Exercise 7 Conclusion
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Comprehensive Physiology - Cardiovascular Reflex Control by Afferent Fibers from Skeletal Muscle Receptors
Comprehensive Physiology, 2011Co-Authors: Jere H Mitchell, Robert F SchmidtAbstract:The sections in this article are: 1 Afferent Fibers from Skeletal Muscle and Their Receptors 1.1 Composition of Muscle Nerves 1.2 Muscle Spindles and Golgi Tendon Organs 1.3 Receptive Properties of Group III and Group IV Afferent Fibers 2 Central Pathways for Cardiovascular Reflexes from Skeletal Muscle Receptors 2.1 Spinal Termination of Primary Muscle Afferents 2.2 Central Pathways Arising From Myelinated Primary Muscle Afferents 2.3 Central Pathways Arising From Unmyelinated Primary Muscle Afferents 2.4 Ascending and Descending Spinal Pathways Involved in Cardiovascular Reflex Control From Skeletal Muscle 3 Organization of Efferent Outflow in Pre- and Postganglionic Neurons 4 Cardiovascular Responses from Skeletal Muscle Receptors 4.1 Effect of Activation of Afferent Fibers 4.2 Effect of Induced Muscular Contraction (Simulated Exercise) 5 Interaction of Muscle Afferents with Other Cardiovascular Reflexes 5.1 Arterial Baroreceptors 5.2 Cardiopulmonary Vagal Afferents 6 Role of Skeletal Muscle Afferents in Cardiovascular Response to Exercise in Humans 6.1 Dynamic and Static Exercise 6.2 Central Control (Central Command) 6.3 Peripheral Control 6.4 Integration of Neural Control Mechanisms During Exercise 7 Conclusion
Hironobu Morita - One of the best experts on this subject based on the ideXlab platform.
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Long-term exposure to microgravity impairs vestibulo-Cardiovascular Reflex.
Scientific reports, 2016Co-Authors: Hironobu Morita, Chikara Abe, Kunihiko TanakaAbstract:The vestibular system is known to have an important role in controlling blood pressure upon posture transition (vestibulo-Cardiovascular Reflex, VCR). However, under a different gravitational environment, the sensitivity of the vestibular system may be altered. Thus, the VCR may become less sensitive after spaceflight because of orthostatic intolerance potentially induced by long-term exposure to microgravity. To test this hypothesis in humans, we investigated the ability of the VCR to maintain blood pressure upon head-up tilt before and after a 4–6 months stay on the International Space Station. To detect the functional state of the VCR, galvanic vestibular stimulation (GVS) was applied. As GVS transiently interrupts the vestibular-mediated pressor response, impaired VCR is detected when the head-up tilt-induced blood pressure response does not depend on GVS. During the first 20 s of head-up tilt, a transient blood pressure increase (11.9 ± 1.6 mmHg) was observed at pre-spaceflight but not at 1–4 days after return from spaceflight. The magnitude of VCR recovered to the pre-spaceflight levels within 2 months after return. These results indicate that long-term exposure to microgravity induces VCR impairment, which may be involved in a mechanism of spaceflight-induced orthostatic intolerance.
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Restriction of rear-up-behavior-induced attenuation of vestibulo-Cardiovascular Reflex in rats.
Neuroscience letters, 2010Co-Authors: Chikara Abe, Akiharu Shibata, Chihiro Iwata, Hironobu MoritaAbstract:Previously, we have demonstrated that the vestibulo-Cardiovascular Reflex was attenuated in rats reared in a 3G environment for 14 days. Because continuous galvanic vestibular stimulation preserved the vestibulo-Cardiovascular Reflex in rats at 3G, this attenuation might be attributable to a reduction in the phasic input to the vestibular system. The present study shows that the head movements of rats were significantly suppressed in the 3G environment. Therefore, we hypothesized that the attenuation of the vestibulo-Cardiovascular Reflex is induced by the reduced vestibular phasic input caused by the restriction of rear-up behavior. To examine this hypothesis, the pressor responses to linear acceleration were measured in rats reared in a low-roof cage. The linear-acceleration-induced pressor response was significantly suppressed in these rats. The suppressive effect of the low-roof cage was similar to that of 3G. There was no difference in the air-jet-induced pressor response among three groups (rats reared in a usual 1G environment, rats reared in the low-roof cage, and rats reared in the 3G environment), suggesting that the sensitivity of the vestibulo-Cardiovascular Reflex was selectively suppressed. These results indicate that a reduction in the vestibular phasic input acts to attenuate the vestibulo-Cardiovascular Reflex.
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Galvanic vestibular stimulation counteracts hypergravity-induced plastic alteration of vestibulo-Cardiovascular Reflex in rats
Journal of applied physiology (Bethesda Md. : 1985), 2009Co-Authors: Chikara Abe, Kunihiko Tanaka, Chihiro Awazu, Hironobu MoritaAbstract:Recent data from our laboratory demonstrated that, when rats are raised in a hypergravity environment, the sensitivity of the vestibulo-Cardiovascular Reflex decreases. In a hypergravity environment, static input to the vestibular system is increased; however, because of decreased daily activity, phasic input to the vestibular system may decrease. This decrease may induce use-dependent plasticity of the vestibulo-Cardiovascular Reflex. Accordingly, we hypothesized that galvanic vestibular stimulation (GVS) may compensate the decrease in phasic input to the vestibular system, thereby preserving the vestibulo-Cardiovascular Reflex. To examine this hypothesis, we measured horizontal and vertical movements of rats under 1-G or 3-G environments as an index of the phasic input to the vestibular system. We then raised rats in a 3-G environment with or without GVS for 6 days and measured the pressor response to linear acceleration to examine the sensitivity of the vestibulo-Cardiovascular Reflex. The horizontal and vertical movement of 3-G rats was significantly less than that of 1-G rats. The pressor response to forward acceleration was also significantly lower in 3-G rats (23 ± 1 mmHg in 1-G rats vs. 12 ± 1 mmHg in 3-G rats). The pressor response was preserved in 3-G rats with GVS (20 ± 1 mmHg). GVS stimulated Fos expression in the medial vestibular nucleus. These results suggest that GVS stimulated vestibular primary neurons and prevent hypergravity-induced decrease in sensitivity of the vestibulo-Cardiovascular Reflex.
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Long-term hypergravity induces plastic alterations in vestibulo-Cardiovascular Reflex in conscious rats
Neuroscience letters, 2006Co-Authors: Hironobu Morita, Chikara Abe, Chihiro Awazu, Kunihiko TanakaAbstract:Abstract To test the hypothesis that an altered gravitational environment induces plastic changes in the vestibulo-Cardiovascular Reflex, arterial pressure (AP) and hypothalamic glutamate concentration were examined in 2 groups of conscious rats, i.e., a 3-G group and a 1-G group, in which rats were maintained under a 3-G and 1-G environment for 2 weeks, respectively. The vestibulo-Cardiovascular Reflex was stimulated by a gravitational change induced by a parabolic flight that consisted of 3 phases: “pull-up”, during which the G load gradually increased to 2 G; a 20 s “push-over” into microgravity; and “pull-out”, during which the G load increased to 1.8. In the 1-G group, the AP increased by 11.9 ± 1.2 mmHg during the pull-up hypergravity period. The AP response was significantly attenuated in the 3-G group (4.0 ± 0.8 mmHg). During the push-over microgravity period, the AP decreased from the peak level in the pull-up period and recovered to the pre-parabolic control level (−1.8 ± 2.4 mmHg). In rats of the 3-G group, the AP was not altered by push-over microgravity. These AP responses were associated with a significant increase in the glutamate concentration in the hypothalamus (4.4 ± 0.7%). The glutamate response was also significantly attenuated in the 3-G group compared with that in the 1-G group. These results indicate that an altered gravitational environment induces plastic alterations in the vestibulo-Cardiovascular Reflex.
P. S. Matusik - One of the best experts on this subject based on the ideXlab platform.
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Cardiovascular Reflex tests in patients with systemic lupus erythematosus: clinical performance and utility.
Lupus, 2018Co-Authors: P. S. Matusik, Phyllis K. SteinAbstract:BackgroundThis review summarizes current knowledge about Cardiovascular Reflex tests (CVRTs) and other selected autonomic nervous system (ANS) assessment tests in systemic lupus erythematosus (SLE)...
Jere H Mitchell - One of the best experts on this subject based on the ideXlab platform.
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Cardiovascular Reflex control by afferent fibers from skeletal muscle receptors
Comprehensive Physiology, 2011Co-Authors: Jere H Mitchell, Robert F SchmidtAbstract:The sections in this article are: 1 Afferent Fibers from Skeletal Muscle and Their Receptors 1.1 Composition of Muscle Nerves 1.2 Muscle Spindles and Golgi Tendon Organs 1.3 Receptive Properties of Group III and Group IV Afferent Fibers 2 Central Pathways for Cardiovascular Reflexes from Skeletal Muscle Receptors 2.1 Spinal Termination of Primary Muscle Afferents 2.2 Central Pathways Arising From Myelinated Primary Muscle Afferents 2.3 Central Pathways Arising From Unmyelinated Primary Muscle Afferents 2.4 Ascending and Descending Spinal Pathways Involved in Cardiovascular Reflex Control From Skeletal Muscle 3 Organization of Efferent Outflow in Pre- and Postganglionic Neurons 4 Cardiovascular Responses from Skeletal Muscle Receptors 4.1 Effect of Activation of Afferent Fibers 4.2 Effect of Induced Muscular Contraction (Simulated Exercise) 5 Interaction of Muscle Afferents with Other Cardiovascular Reflexes 5.1 Arterial Baroreceptors 5.2 Cardiopulmonary Vagal Afferents 6 Role of Skeletal Muscle Afferents in Cardiovascular Response to Exercise in Humans 6.1 Dynamic and Static Exercise 6.2 Central Control (Central Command) 6.3 Peripheral Control 6.4 Integration of Neural Control Mechanisms During Exercise 7 Conclusion
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Comprehensive Physiology - Cardiovascular Reflex Control by Afferent Fibers from Skeletal Muscle Receptors
Comprehensive Physiology, 2011Co-Authors: Jere H Mitchell, Robert F SchmidtAbstract:The sections in this article are: 1 Afferent Fibers from Skeletal Muscle and Their Receptors 1.1 Composition of Muscle Nerves 1.2 Muscle Spindles and Golgi Tendon Organs 1.3 Receptive Properties of Group III and Group IV Afferent Fibers 2 Central Pathways for Cardiovascular Reflexes from Skeletal Muscle Receptors 2.1 Spinal Termination of Primary Muscle Afferents 2.2 Central Pathways Arising From Myelinated Primary Muscle Afferents 2.3 Central Pathways Arising From Unmyelinated Primary Muscle Afferents 2.4 Ascending and Descending Spinal Pathways Involved in Cardiovascular Reflex Control From Skeletal Muscle 3 Organization of Efferent Outflow in Pre- and Postganglionic Neurons 4 Cardiovascular Responses from Skeletal Muscle Receptors 4.1 Effect of Activation of Afferent Fibers 4.2 Effect of Induced Muscular Contraction (Simulated Exercise) 5 Interaction of Muscle Afferents with Other Cardiovascular Reflexes 5.1 Arterial Baroreceptors 5.2 Cardiopulmonary Vagal Afferents 6 Role of Skeletal Muscle Afferents in Cardiovascular Response to Exercise in Humans 6.1 Dynamic and Static Exercise 6.2 Central Control (Central Command) 6.3 Peripheral Control 6.4 Integration of Neural Control Mechanisms During Exercise 7 Conclusion