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Functional Connections of the Vestibulo-spino-adrenal Axis in the Control of Blood Pressure Via the Vestibulosympathetic Reflex in Conscious Rats.

Lu HJ, Li MH, Li MZ, Park SE, Kim MS, Jin YZ, Park BR - Korean J. Physiol. Pharmacol. (2015)

Bottom Line: Significant evidence supports the role of the vestibular system in the regulation of blood pressure during postural movements.In the present study, the role of the vestibulo-spino-adrenal (VSA) axis in the modulation of blood pressure via the vestibulosympathetic reflex was clarified by immunohistochemical and enzyme immunoassay methods in conscious rats with sinoaortic denervation.These results indicate that the VSA axis may be a key component of the pathway used by the vestibulosympathetic reflex to maintain blood pressure during postural movements.

View Article: PubMed Central - PubMed

Affiliation: Department of Physiology and Pathophysiology, Yanbian University College of Medicine and Key Laboratory of Natural Resources of Changbai Mountain & Functional Molecules at Yanbian University, Yanji 133002, China.

ABSTRACT
Significant evidence supports the role of the vestibular system in the regulation of blood pressure during postural movements. In the present study, the role of the vestibulo-spino-adrenal (VSA) axis in the modulation of blood pressure via the vestibulosympathetic reflex was clarified by immunohistochemical and enzyme immunoassay methods in conscious rats with sinoaortic denervation. Expression of c-Fos protein in the intermediolateral cell column of the middle thoracic spinal regions and blood epinephrine levels were investigated, following microinjection of glutamate receptor agonists or antagonists into the medial vestibular nucleus (MVN) and/or sodium nitroprusside (SNP)-induced hypotension. Both microinjection of glutamate receptor agonists (NMDA and AMPA) into the MVN or rostral ventrolateral medullary nucleus (RVLM) and SNP-induced hypotension led to increased number of c-Fos positive neurons in the intermediolateral cell column of the middle thoracic spinal regions and increased blood epinephrine levels. Pretreatment with microinjection of glutamate receptor antagonists (MK-801 and CNQX) into the MVN or RVLM prevented the increased number of c-Fos positive neurons resulting from SNP-induced hypotension, and reversed the increased blood epinephrine levels. These results indicate that the VSA axis may be a key component of the pathway used by the vestibulosympathetic reflex to maintain blood pressure during postural movements.

No MeSH data available.


Related in: MedlinePlus

Schematic diagram of the vestibulo-spino-adrenal (VSA) axis in the vestibulosympathetic reflex. Dotted lines represent pathway of the VSA axis. VNC, vestibular nuclear complex; NTS, nucleus tractus solitarius; CVLM, caudal ventrolateral medulla; RVLM, rostral ventrolateral medulla; IML, intermediolateral cell column of the spinal cord; AM, adrenal medulla.
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Figure 7: Schematic diagram of the vestibulo-spino-adrenal (VSA) axis in the vestibulosympathetic reflex. Dotted lines represent pathway of the VSA axis. VNC, vestibular nuclear complex; NTS, nucleus tractus solitarius; CVLM, caudal ventrolateral medulla; RVLM, rostral ventrolateral medulla; IML, intermediolateral cell column of the spinal cord; AM, adrenal medulla.

Mentions: The major source of descending drive to the sympathetic preganglionic neurons of the spinal cord is the spinally-projecting neurons in the RVLM [31]. Excitation of the RVLM increases blood pressure and sympathetic vasomotor tone, whereas inhibition of the RVLM decreases blood pressure. The activity in the bulbospinal sympathoexcitatory pathways [32] is modulated by afferent signals from both the baroreceptors and vestibular receptors. Since glutamate is a major excitatory neurotransmitter in the vestibular nuclei, microinjection of glutamate receptor agonists into the MVN causes excitation of the vestibular nuclear neurons [33]. The MVN sends direct projections to the RVLM, which is involved in the regulation of sympathetic outflow [1734]. In turn, the RVLM sends excitatory projections to the sympathetic pre-ganglionic neurons in the intermediolateral cell column of the spinal cord [1]. Therefore, stimulation of the MVN may produce excitation of the sympathetic preganglionic neurons in the spinal cord through the bulbospinal sympathoexcitatory pathways (Fig. 7).


Functional Connections of the Vestibulo-spino-adrenal Axis in the Control of Blood Pressure Via the Vestibulosympathetic Reflex in Conscious Rats.

Lu HJ, Li MH, Li MZ, Park SE, Kim MS, Jin YZ, Park BR - Korean J. Physiol. Pharmacol. (2015)

Schematic diagram of the vestibulo-spino-adrenal (VSA) axis in the vestibulosympathetic reflex. Dotted lines represent pathway of the VSA axis. VNC, vestibular nuclear complex; NTS, nucleus tractus solitarius; CVLM, caudal ventrolateral medulla; RVLM, rostral ventrolateral medulla; IML, intermediolateral cell column of the spinal cord; AM, adrenal medulla.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4553402&req=5

Figure 7: Schematic diagram of the vestibulo-spino-adrenal (VSA) axis in the vestibulosympathetic reflex. Dotted lines represent pathway of the VSA axis. VNC, vestibular nuclear complex; NTS, nucleus tractus solitarius; CVLM, caudal ventrolateral medulla; RVLM, rostral ventrolateral medulla; IML, intermediolateral cell column of the spinal cord; AM, adrenal medulla.
Mentions: The major source of descending drive to the sympathetic preganglionic neurons of the spinal cord is the spinally-projecting neurons in the RVLM [31]. Excitation of the RVLM increases blood pressure and sympathetic vasomotor tone, whereas inhibition of the RVLM decreases blood pressure. The activity in the bulbospinal sympathoexcitatory pathways [32] is modulated by afferent signals from both the baroreceptors and vestibular receptors. Since glutamate is a major excitatory neurotransmitter in the vestibular nuclei, microinjection of glutamate receptor agonists into the MVN causes excitation of the vestibular nuclear neurons [33]. The MVN sends direct projections to the RVLM, which is involved in the regulation of sympathetic outflow [1734]. In turn, the RVLM sends excitatory projections to the sympathetic pre-ganglionic neurons in the intermediolateral cell column of the spinal cord [1]. Therefore, stimulation of the MVN may produce excitation of the sympathetic preganglionic neurons in the spinal cord through the bulbospinal sympathoexcitatory pathways (Fig. 7).

Bottom Line: Significant evidence supports the role of the vestibular system in the regulation of blood pressure during postural movements.In the present study, the role of the vestibulo-spino-adrenal (VSA) axis in the modulation of blood pressure via the vestibulosympathetic reflex was clarified by immunohistochemical and enzyme immunoassay methods in conscious rats with sinoaortic denervation.These results indicate that the VSA axis may be a key component of the pathway used by the vestibulosympathetic reflex to maintain blood pressure during postural movements.

View Article: PubMed Central - PubMed

Affiliation: Department of Physiology and Pathophysiology, Yanbian University College of Medicine and Key Laboratory of Natural Resources of Changbai Mountain & Functional Molecules at Yanbian University, Yanji 133002, China.

ABSTRACT
Significant evidence supports the role of the vestibular system in the regulation of blood pressure during postural movements. In the present study, the role of the vestibulo-spino-adrenal (VSA) axis in the modulation of blood pressure via the vestibulosympathetic reflex was clarified by immunohistochemical and enzyme immunoassay methods in conscious rats with sinoaortic denervation. Expression of c-Fos protein in the intermediolateral cell column of the middle thoracic spinal regions and blood epinephrine levels were investigated, following microinjection of glutamate receptor agonists or antagonists into the medial vestibular nucleus (MVN) and/or sodium nitroprusside (SNP)-induced hypotension. Both microinjection of glutamate receptor agonists (NMDA and AMPA) into the MVN or rostral ventrolateral medullary nucleus (RVLM) and SNP-induced hypotension led to increased number of c-Fos positive neurons in the intermediolateral cell column of the middle thoracic spinal regions and increased blood epinephrine levels. Pretreatment with microinjection of glutamate receptor antagonists (MK-801 and CNQX) into the MVN or RVLM prevented the increased number of c-Fos positive neurons resulting from SNP-induced hypotension, and reversed the increased blood epinephrine levels. These results indicate that the VSA axis may be a key component of the pathway used by the vestibulosympathetic reflex to maintain blood pressure during postural movements.

No MeSH data available.


Related in: MedlinePlus