Pittman Q J, Blume H W, Renaud L P
Brain Res. 1981 Jun 29;215(1-2):15-28. doi: 10.1016/0006-8993(81)90488-1.
Extracellular recordings were obtained from 555 paraventricular (PVN) nucleus neurons in pentobarbital-anesthetized male rats. Cells were examined for their spontaneous activity patterns and response to single 1-Hz electrical stimulation of the neurohypophysis, median eminence, amygdala, lateral septum (LS) and midbrain periaqueductal gray (PAG). Neurohypophyseal stimulation evoked antidromic activation from 109 neurons. Among spontaneously active neurohypophyseal neurons, evidence of a recurrent inhibitory pathway usually required pituitary stimulus intensities twice threshold for antidromic activation. Orthodromic excitatory or inhibitory responses followed amygdala and LS stimulation, but not PAG stimulation. The amygdala influence was predominantly inhibitory to 'phasic' (putative vasopressin-secreting) PVN neurohypophyseal neurons. Neurohypophyseal stimulation evoked orthodromic responses from 124 PVN cells; some of these neurons were also responsive to stimulation in other sites. Median eminence stimulation evoked antidromic responses from 37 PVN neurons; some of these cells also displayed phasic activity but no evidence for recurrent inhibition. Twelve cells in this group were also activated antidromically from both the median eminence and the neurohypophysis; collision tests suggest that the median eminence innervation may be an axon collateral of a neurohypophyseal pathway. Amygdala stimulation was inhibitory to some cells in this category. Amygdala, LS and PAG stimulation evoked antidromic activation from a small number of PVN cells, but none of these cells appeared to innervate more than one area, including the neurohypophysis, and none displayed phasic activity. Orthodromic responses were recorded among other PVN neurons after stimulation in these sites; however, PAG stimulation was the least effective stimulation area. These observations provide additional electrophysiological data that confirm efferent PVN connections to all areas tested, afferent connections from amygdala and LS but not PAG, and the possibility for coordinated activity among PVN neurons through local recurrent or common afferent connections.
在戊巴比妥麻醉的雄性大鼠中，从555个室旁核（PVN）神经元进行了细胞外记录。检测细胞的自发活动模式以及对神经垂体、正中隆起、杏仁核、外侧隔（LS）和中脑导水管周围灰质（PAG）单次1赫兹电刺激的反应。神经垂体刺激引起109个神经元的逆向激活。在自发活动的神经垂体神经元中，通常需要垂体刺激强度达到逆向激活阈值的两倍，才能有反复抑制通路的证据。杏仁核和LS刺激后出现顺向兴奋性或抑制性反应，但PAG刺激后未出现。杏仁核的影响主要是抑制“相位性”（假定分泌加压素的）PVN神经垂体神经元。神经垂体刺激引起124个PVN细胞的顺向反应；其中一些神经元也对其他部位的刺激有反应。正中隆起刺激引起37个PVN神经元的逆向反应；其中一些细胞也表现出相位性活动，但没有反复抑制的证据。该组中的12个细胞也被正中隆起和神经垂体逆向激活；碰撞试验表明，正中隆起的神经支配可能是神经垂体通路的轴突侧支。杏仁核刺激对该类别中的一些细胞有抑制作用。杏仁核、LS和PAG刺激引起少数PVN细胞的逆向激活，但这些细胞中没有一个似乎支配不止一个区域，包括神经垂体，也没有一个表现出相位性活动。在这些部位刺激后，在其他PVN神经元中记录到了顺向反应；然而，PAG刺激是最无效的刺激区域。这些观察结果提供了额外的电生理数据，证实了PVN与所有测试区域的传出连接、来自杏仁核和LS而非PAG的传入连接，以及PVN神经元之间通过局部反复或共同传入连接进行协同活动的可能性。
