Identification of cardiovascular neurons in the rostral ventromedial medulla in anesthetized rats.
Identification of cardiovascular neurons in the rostral ventromedial medulla in anesthetized rats.
复制标题
麻醉大鼠延髓头侧腹内侧心血管神经元的鉴定。
DOI：
10.1161/01.hyp.19.2_suppl.ii193
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
Brody,MJ
中科院分区：
文献类型：
--
作者：
Varner,KJ;Rutherford,DS;Vasquez,EC;Brody,MJ
最近的研究已经在大鼠的吻侧腹内侧髓质（RVMM）中发现了一个似乎与心血管功能有关的区域。由于这些研究要么使用利多卡因显微注射，要么使用电刺激，因此无法确定固有神经元的确切作用，而不是传递纤维。本研究通过显微注射选择性激活巴比妥酸麻醉大鼠细胞体的兴奋性氨基酸类似物n -甲基- d -天冬氨酸（NMDA） （20 ng/50 nl），绘制了RVMM中神经元的位置，从而引起平均动脉压的变化。在RVMM中微量注射NMDA最常（53%）引起升压反应（31 +/- 7 mm Hg）。在这些反应的基础上，RVMM被确定为包括巨大细胞核中线外侧0.5-1.5 mm，腹面上方0.5-3.5 mm的大部分，并从吻侧延伸到面核的尾极。降压反应（-21 +/- 3 mm Hg）在所有水平的RVMM中均有发现，但在RVMM的吻侧和尾侧极最为集中，且幅度最大。通过微量注射抑制性神经递质甘氨酸（500 mM）来确定RVMM中的神经元是否有助于维持动脉压。显微注射甘氨酸可降低大部分RVMM的动脉压（-15 +/- 2 mmhg）。出乎意料的是，将甘氨酸微量注射到RVMM中NMDA最常引起升压反应的同一区域，可引起平均动脉压升高（24 +/- 3 mm Hg）。（摘要删节250字）
Recent studies have identified a region in the rostral ventromedial medulla (RVMM) of rats that appears to be involved in cardiovascular function. Since these studies used either microinjection of lidocaine or electrical stimulation, the exact contribution of intrinsic neurons as opposed to fibers of passage could not be determined. The present study was performed to map the location of neurons in RVMM from which changes in mean arterial pressure could be elicited by the microinjection of the excitatory amino acid analogue N-methyl-D-aspartic acid (NMDA) (20 ng/50 nl), which selectively activates cell bodies in barbiturate-anesthetized rats. Microinjection of NMDA into RVMM most often (53%) elicited pressor responses (31 +/- 7 mm Hg). On the basis of these responses, RVMM was determined to encompass a large portion of the nucleus gigantocellularis 0.5-1.5 mm lateral to the midline, 0.5-3.5 mm above the ventral surface, and extending from the rostral to the caudal pole of the facial nucleus. Depressor responses (-21 +/- 3 mm Hg) were found at all levels of RVMM but were most concentrated and of the largest magnitude in the rostral and caudal poles of RVMM. Microinjection of the inhibitory neurotransmitter glycine (500 mM) was used to determine whether neurons in RVMM were contributing to the maintenance of arterial pressure. Microinjection of glycine decreased arterial pressure (-15 +/- 2 mm Hg) throughout most of RVMM. Unexpectedly, increases in mean arterial pressure (24 +/- 3 mm Hg) were elicited by microinjection of glycine into the same region in RVMM in which NMDA most frequently elicited pressor responses.(ABSTRACT TRUNCATED AT 250 WORDS)