BRAINSTEM GUSTATORY PROCESSING

描述(改编自研究人员摘要)：解剖学， 味觉和内脏的电生理和药理数据 路径提出了几个关于功能的可测试的假说 孤束核组织(NST)。少年派的 实验室已经证明，NST中的味觉细胞是由外周驱动的 通过兴奋性氨基酸来品尝纤维，这些细胞是有张力的 被GABA抑制，NST中的味觉反应细胞被兴奋和 有时会被神经肽P物质抑制，电流 应用程序将通过解决三个具体目标来扩展这些发现。 首先，NST中的抑制机制及其在形成 味觉神经元的反应性将被进一步研究。首字母 实验将确定GABAB和甘氨酸受体是否有助于 在NST和IF抑制中的抑制使调谐的广度锐化 NST神经元对味觉刺激的反应。更多的实验将确定 味觉神经元之间在抑制控制方面存在差异 将信息传递给臂旁核(中继神经元)和那些 不要(不传递神经元)。第二个目标是确定 味觉新皮质和丘脑中央核的下行传入 NST上的杏仁核味觉神经元。初步实验将检验 假设来自新皮质和杏仁核的下行输入产生 NST细胞的兴奋性和抑制性调制。随后的实验 将检验兴奋性输入是由 兴奋性氨基酸和抑制性氨基酸的抑制性输入。 这一目标的最后一组实验将评估以下假设 中继神经元受到中枢输入的调制与非中继神经元不同 神经元。最终的具体目标将解决调制的问题 神经肽对NST的味觉反应，尤其是表观 P物质对氯化钠最佳神经元的优先兴奋作用 甲硫氨酸脑啡肽对NST味觉神经元的影响及其可能的差异性调制 神经肽对中继神经元和非中继神经元的影响也将被研究。 这些活体实验旨在揭示突触是如何 NST中的相互作用以及与这一核控制的联系 NST神经元对味觉输入的反应。这些研究将提供 重要的新信息为我们理解功能 中央味觉系统的组织。

DESCRIPTION (Adapted from investigator's abstract): Anatomical, electrophysiological and pharmacological data on gustatory and visceral pathways suggest several testable hypotheses about the functional organization of the nucleus of the solitary tract (NST). The PI's laboratory has shown that taste cells in the NST are driven by peripheral taste fibers via excitatory amino acids, that these cells are tonically inhibited by GABA and that taste-responsive cells in the NST are excited and sometimes inhibited by the neuropeptide, substance P. The current application will extend these findings by addressing three specific aims. First, the mechanisms of inhibition in the NST and its role in shaping the responsiveness of gustatory neurons will be further investigated. Initial experiments will determine if GABAB and glycine receptors contribute to inhibition in the NST and if inhibition sharpens the breadth of tuning of NST neurons to gustatory stimuli. Additional experiments will determine if there are differences in inhibitory control between gustator neurons that relay information to the parabrachial nuclei (relay neurons) and those that do not (nonrelay neurons). The second aim is to determine the influence of descending inputs from the gustatory neocortex and the central nucleus of the amygdala on NST taste neurons. Initial experiments will examine the hypothesis that descending inputs from the neocortex and amygdala produce excitatory and inhibitory modulation of NST cells. Subsequent experiments will test the hypotheses that the excitatory inputs are mediated by excitatory amin acids and the inhibitory inputs by inhibitory amino acids. The final set of experiments in this aim will evaluate the hypothesis that relay neurons are modulated differently by central inputs than nonrelay neurons. The final specific aim will address the question of modulation of NST taste responses by neuropeptides, and in particular, the apparent preferential excitation of NaCl-best neurons by substance P. The effects of met-enkephalin on NST taste neurons and the possible differential modulation of neuropeptide effects on relay and nonrelay neurons will also be examined. These in vivo experiments ar designed to reveal how the synaptic interactions in the NST and the connection to and from this nucleus control responses of NST neurons to gustatory inputs. These studies will provide important new information for our understanding of the functional organization of the central gustatory system.