NEUROTRANSMITTERS AND CENTRAL CONTROL OF BLOOD PRESSURE

描述（研究者摘要）： 血压可能是由于干扰发射机机制， 孤束核（NTS），初级的终止部位 心血管传入神经 因此，对假定的 NTS中的发射机可以增加对中央控制的理解， 血压. 首席研究员此前曾表示， 在NTS中释放甘氨酸（GLY）。 微量注射氨基酸 进入背侧NTS的抑制和心动过缓反应， 性质上类似于兴奋性氨基酸谷氨酸（GLU），而 注射到腹侧NTS和迷走神经背侧运动核（DMV） 导致升压心动过速反应 研究者的研究 实验室支持乙酰胆碱的作用， 甘氨酸-谷氨酸受体的相互作用，在调解这些 心血管反应 研究者将检验以下假设： GLY可通过胆碱能途径增强孤束核的心血管反应 机制，特别是通过释放乙酰胆碱。 GLY的作用 将测试心血管反射中的NTS，并从 将确定NTS中功能不同的位点。 的作用 ACh在介导对GLY的反应中的作用将被评估， 将确定GLY导致ACh释放的程度。 免疫细胞 方法将用于识别和定位含GLY的末端， GLY受体，以及这些GLY元件与胆碱能受体的关系 将研究神经元和神经过程。 最后 GLY终末与心血管传入纤维之间的关系将 研究以确定GLY是否可从初级传入神经释放 或来自NTS内的中间神经元。

DESCRIPTION (Investigator's Abstract): Disturbances in the regulation of blood pressure may result from perturbations of transmitter mechanisms in the nucleus tractus solitarius (NTS), the site of termination of primary cardiovascular afferents. Thus, definition of the role played by putative transmitters in the NTS may increase understanding of central control of blood pressure. The principal investigator had previously shown that glycine (GLY) is released in the NTS. Micorinjection of the amino acid into the dorsal NTS elicits a depressor and bradycardiac response that is qualitatively like that of the excitatory amino acid glutamate (GLU), while injections into the ventral NTS and dorsal motor nucleus of the vagus (DMV) result in pressor, tachycardiac responses. Studies from the investigator's laboratory have supported a role for ACh, and have not supported glycine-glutamate receptor interactions in the mediation of these cardiovascular responses. The investigator will test the hypothesis that GLY elicits cardiovascular responses from the NTS through cholinergic mechanisms and specifically through the release of ACh. The role of GLY in the NTS in cardiovascular reflexes will be tested and projections from the functionally different sites in the NTS will be determined. The role of ACh in mediating the responses to GLY will be assessed and the mechanisms by which GLY leads to ACh release will be determined. Immunocytochemical methods will be used to identify and localize GLY-containing terminals and GLY receptors, and the relationship of those GLY elements to cholinergic neurons and nerve processes will be investigated. Finally, the relationship between GLY terminals and cardiovascular afferent fibers will be investigated to determine if GLY may be released from primary afferents or from interneurons within the NTS.