NEUROPEPTIDE-Y IN THE HYPOTHALAMUS - EFFECT ON CORTICOSTERONE AND SINGLE-UNIT ACTIVITY
NEUROPEPTIDE-Y IN THE HYPOTHALAMUS - EFFECT ON CORTICOSTERONE AND SINGLE-UNIT ACTIVITY
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DOI：
10.1152/ajpregu.1990.258.2.r376
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发表时间：
1990-02-01
影响因子：
--
通讯作者：
ANDERSON, ER
中科院分区：
文献类型：
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作者：
ALBERS, HE;OTTENWELLER, JE;ANDERSON, ER
本研究的目的是确定神经肽Y（NPY）是否作用于下丘脑室旁核（PVN）或视交叉上核（SCN），以改变皮质酮的循环水平，并评估NPY对PVN和SCN神经元的单位反应的影响使用下丘脑切片制备。在接受微量注射NPY或盐水（Sal）到PVN或SCN的大鼠组中测定皮质酮的血液水平。在光照开始后4小时将NPY注射到PVN中导致皮质酮水平为13.15 ± 0.05。2.18（SE）μ g/dl，其显著高于皮质酮水平4.08 ±。1.78μ g/dl。与此相反，没有观察到显着差异，在循环水平的皮质酮组之间的大鼠1或4小时后，神经肽Y或水杨酸微量注射到SCN。在下丘脑切片中，发现NPY主要在SCN和PVN神经元中产生抑制反应。49%的SCN单位被抑制。此外，在SCN中测试的另外20%的神经元显示出兴奋，随后是更持续的抑制。在PVN中，45%的单位被NPY抑制，然而，近30%的剩余神经元被NPY显著兴奋。总之，NPY改变SCN和PVN神经元的电活动，但似乎只在PVN内影响皮质酮的循环水平。这些和其他数据表明，神经肽Y作为一个重要的神经化学信使在几个下丘脑网站。
The purpose of the present study was to determine whether neuropeptide Y (NPY) acts within the hypothalamic paraventricular nucleus (PVN) or the suprachiasmatic nucleus (SCN) to alter circulating levels of corticosterone and to evaluate the effects of NPY on the single-unit response of PVN and SCN neurons using the hypothalamic slice preparation. Blood levels of corticosterone were determined in groups of rats that received microinjections of NPY or saline (Sal) into the PVN or SCN. NPY injected into the PVN 4 h after light onset resulted in corticosterone levels of 13.15 .+-. 2.18 (SE) .mu.g/dl within 1 h, which were significantly higher than the corticosterone levels of 4.08 .+-. 1.78 .mu.g/dl seen in rats receiving Sal injections. In contrast, no significant differences were observed in circulating levels of corticosterone between groups of rats 1 or 4 h after NPY or Sal microinjection into the SCN. In the hypothalamic slice, NPY was found to produce primarily inhibitory responses in both SCN and PVN neurons. Forty-nine percent of the SCN units examined were inhibited. In addition, another 20% of the neurons tested in the SCN displayed excitation followed by more sustained inhibition. In the PVN, 45% of the units examined were inhibited by NPY, however, nearly 30% of the remaining neurons were significantly excited by NPY. In summary, NPY alters the electrical activity of both SCN and PVN neurons but appears to act only within the PVN to influence circulating levels of corticosterone. These and other data indicate that NPY acts as an important neurochemical messenger within several hypothalamic sites.