用免疫组织化学方法显示电生理记录部位神经元的化学性质——离体脑片法研究

500μm厚的冠状脑片取自新鲜大鼠下丘脑前部。在人工孵育条件下进行电生理观察,看到前连合核和第三脑室前部室周区部分神经元的电活动可被人工脑脊液中加入血管紧张素Ⅱ所兴奋,被提高人工脑脊液中的Ca~(++)浓度所抑制。这些电生理反应与大细胞内分泌神经元的电生理特性一致。记录结束时,记录部位用记录电极中的染料标记,脑片浸泡固定4—8h,恒冷箱切片,用抗催产素和抗加压素抗体孵育,ABC反应。结果在记录电极尖端所在部位看到数量不等的催产素或加压素免疫阳性神经元。上述电生理和免疫组化结果表明,研记录到的部分神经元可能含催产素或加压素免疫反应物质。本文报告了用免疫组织化学方法显示离体电生理标本,特别是记录部位神经元的免疫化学特性的实验结果。

IMMUNOSTAINING OF NEURONS AT SITES OF ELECTROPHYSIOLOGICAL RECORDING——A BRAIN SLICE STUDY

A method for combining neuronal electrophysiological study with immunocytochemistry on rat brain slice is described. Spontaneous unit discharges of neurons in the anterior commissure nucleus and periventricular zone were recorded extracellularly in vitro. The firing rates of some of these two group neurons were increased and decreased profoundly by adminstration of angi tensin via artificial cerebrospinal fluid and elevation of Ca~(++) level from 0.75 to 2.4 mM/L in perfusing medium respectively. These neuronal responses were consistent with electrophysiological properties of magnocellular neurosecretory neurons. Following the immunostaining with antisera against oxytocin and vasopressin, positive immunoreactive neurons were found around the recording sites in the anterior commissure nucleus and periventricular zone. These results suggest that some of the recorded neurons might be oxytocinergic or vasopressinergic.