Convergent central pathways for sympatho-inhibition

描述（由申请人提供）：中枢神经系统协调 适当的行为和生理事件， 环境挑战，但许多机制仍有待确定。的 本研究将侧重于一个单一的组成部分，这是共同的一些 行为和条件，以确定是否收敛中央通路 存在.交感神经抑制是基础的恢复阶段， 防御反应以及对严重出血的反应。本 该提案旨在描述中央途径介导的 交感神经抑制在这些条件下，并确定是否 交感神经抑制通过会聚到共同的中枢通路来介导。 背景和初步数据表明，在这两种情况下， 交感神经抑制通过最终共同途径经由5-HTIA介导 延髓头端腹外侧交感兴奋区的受体 （RVLM）。这将提供一种新的多巴胺能途径， 与介导反射不同交感神经抑制 通过GABA受体对交感神经兴奋性神经元的交感神经抑制。 拟议的研究将扩展一项发现，即交感神经抑制引起的 从中脑导水管周围灰质的腹外侧通过 RVLM中5-HT 1A受体的活化。交感神经和中枢单位 记录结合显微注射技术将被用来 从中脑导水管周围探讨交感神经抑制的通路 灰色通过RVLM 5-HTIA受体，并确定其参与恢复 防御反应的阶段。研究还将审查一个假定的作用， 在极度出血期间RVLM中5-HT 1A受体的激活。的 这些研究的结果将提供深入了解的收敛程度， 中枢通路介导的交感神经抑制在恢复阶段的一个 防御反应和极度出血期间。 该提案的长期目标是描述一种途径， 介导对多种条件至关重要的特定神经反应。这些 新的数据将对一系列病理学具有潜在的意义， 行为，包括情绪行为、镇痛、休克、性功能和 晕倒了

DESCRIPTION (provided by applicant): The central nervous system coordinates appropriate behavioral and physiological events in response to imposed environmental challenges but many mechanisms remain to be determined. The present study will focus on a single component which is common to a number of behaviors and conditions to determine whether convergent central pathways exist. Sympatho-inhibition is fundamental to both the recovery phase of a defense response and also to the response to severe hemorrhage. The present proposal is designed to characterize central pathways mediating sympatho-inhibition during these conditions and determine if the sympatho-inhibition is mediated by convergence to a common central pathway. Background and preliminary data suggests that under both conditions sympatho-inhibition is mediated through a final common pathway via 5-HTIA receptors in the sympatho-excitatory region of the rostroventrolateral medulla (RVLM). This would provide a novel serotonergic pathway generating sympatho-inhibition which is distinct from that mediating reflex sympatho-inhibition via GABA receptors on sympatho-excitatory neurons. The proposed studies will extend a finding that a sympatho-inhibition elicited from the ventrolateral periaqueductal gray matter is mediated through activation of 5-HTIA receptors in the RVLM. Sympathetic nerve and central unit recordings combined with microinjection techniques will be utilized to investigate the pathway mediating sympatho-inhibition from the periaqueductal gray via RVLM 5-HTIA receptors, and determine its involvement in the recovery phase of a defense response. Studies will also examine a putative role for activation of 5-HTIA receptors in the RVLM during extreme hemorrhage. The results of these studies will provide insight into the extent of convergence of central pathways mediating sympatho-inhibition during the recovery phase of a defense response and during extreme hemorrhage. The long-term aim of this proposal is to characterize a pathway which may mediate a specific neural response essential to multiple conditions. These novel data will be of potential significance to an array of pathologies and behaviors including emotional behaviors, analgesia, shock, sexual function and fainting.