REGULATION OF CEREBRAL BLOOD FLOW BY THE ROSTRAL VENTROLATERAL MEDULLA

这一持续项目的目标是调查 吻部神经元的机制和途径 延髓腹外侧部(RVL)调节脑循环。 兴奋RVL神经元可提高局部脑血流量 大脑皮层内的血流(RCBF)而不升高大脑 新陈代谢。这些神经元也介导了一半的 脑血管扩张以耐缺氧。三项研究将是 它结合了微电子和化学的方法 刺激、神经元失活、记录生物电活动 和rCBF，并进行示踪和免疫细胞化学 麻醉大鼠。项目I将检验以下假设：(A) 尾侧RVL内一组特殊神经元的兴奋 (RVLc)升高大脑皮层rCBF；(B)这些RVLc 神经元受FN、NTS和氧气的反射性兴奋 嘴侧RVL敏感神经元(RVLr)； 来自RVLc的皮质是间接的，通过皮质下皮质传递 投射可能局限于Z1；(D)血管扩张作用 Zl神经元RVLc的兴奋依赖于 皮层神经元最终表达升高的rCBF；(E) RVLS中所代表的血管扩张途径是常见的 激活FN、NTS和RVLr的途径 导致脑电减慢和rCBF升高。这项研究 将第一次提供完整的途径的证据 脑干将内脏传入活动与循环联系起来 脑电活动。

The objective of this continuing project is to investigate the mechanisms and pathway through which neurons in the rostral ventrolateral medulla (RVL) regulate the cerebral circulation. Excitation of neurons of the RVL elevates regional cerebral blood flow (rCBF) within the cerebral cortex without elevating cerebral metabolism. These neurons also mediate half of the cerebrovascular vasodilation to hypoxia. Three studies will be undertaken which combine methods of microelectrical and chemical stimulation, neuronal inactivation, recording of bioelectrical activity and rCBF, and tract tracing and immunocytochemistry in anesthetized rats. Project I will test the hypotheses that (a) excitation of a distinctive group of neurons in the caudal RVL (RVLc) elevates rCBF in the cerebral cortex; (b) these RVLc neurons are reflexively excited from FN, NTS, and oxygen sensitive neurons of rostral RVL (RVLr); (c) the pathway to the cortex from RVLc is indirect and relays through a subcortical projection probably localized to Zl; (d) vasodilatory effects of excitation of RVLc of Zl neurons depend upon the integrity of cortical neurons for the final expression of elevated rCBF; (e) the vasodilator pathway represented in the RVLs is the common pathway through which activation of FN, NTS, and RVLr also produces a slowing of the EEG and elevation of rCBF. The study will provide evidence for the first time of a full pathway of the brainstem linking visceral afferent activity with the circulation and electrical brain activity.