大鼠第三脑室一氧化氮合酶阳性触液神经元的分布及与催产素的共存

应用 NADPH-d组织化学方法观察了大鼠第三脑室一氧化氮合酶阳性触液神经元的分布及其形态 ,并结合免疫组织化学技术研究了一氧化氮合酶与催产素在第三脑室触液神经元内的共存。结果显示 :在视前区至室间核后大细胞亚核平面的第三脑室室壁均有一氧化氮合酶阳性触液神经元分布 ,呈自前向后 ,由腹侧部渐向背侧部过渡迁移的特征。一氧化氮合酶阳性触液神经元绝大部分为大细胞型标记神经元 ,胞体呈卵圆形、梭形、多角形与倒置梨形。它们位于脑室管膜内、室管膜下 ,或距室管膜有一定距离处 ,但有突起伸至第三脑室。第三脑室催产素免疫阳性触液神经元的形态及分布与一氧化氮合酶阳性触液神经元基本相似 ,两者高度共存。催产素 /一氧化氮合酶双标神经元 ,约占阳性细胞总数的 90 .9%。上述三种阳性触液神经元与邻近核团关系密切 ,尤其与室旁核之间有很多的阳性纤维互相交错。本研究结果表明 ,第三脑室有大量的一氧化氮合酶与催产素免疫阳性神经元分布 ,并且高度共存 ,从而建立了催产素的下丘脑 -脑脊液 -垂体神经体液调节环路的结构基础 ,对生殖与性行为起着重要的调控作用

THE DISTRIBUTION OF NITRIC OXIDE SYNTHASE POSITIVE CEREBROSPINAL FLUID-CONTACTING NEURONS AND COEXISTENCE WITH OXYTOCIN IN THE REGION OF THE THIRD VENTRICLE IN THE RAT

NADPH-diaphorase histochemistry method was used to investigate the distribution and morphology of nitric oxide synthase (NOS) positive cerebrospinal fluid-contacting neurons (CSFCN) in the periventricular region of the third ventricle in the rat. The coexistence of NOS with oxytocin (OT) was also studied in the CSFCN by using histochemical technique combined with immunocytochemical methods in the same section. NOS-CSFCN were located in the wall of the third ventricle from the preoptic area to posterior magnocellular paraventricular nucleus levels, migrating from anterior ventral area to posterior dorsal area. The overwhelming majority of labelled cell was magnocellular neurosecretory neurons, and classified into four types, such as oval, fusiform, multi-angle, and inverting pear shape. They were located in the ependymal layer, subependymal layer or region with some distance to the ependyma, sending processes into the third ventricle. The distribution and morphology of OT-CSFCN in the periventricular region of the third ventricle was similar to NOS-CSFCN on the whole, and the ratio of coexistence of NOS-OT was very high. The percentage of double labeled neurons to total labeled neurons was 90.9%. The above-mentioned three kinds labeled neurons showed a close connection with the neighboring region, especially with a large number of labeled fibres mixing and contacting with paraventricular nucleus. These results suggest that the distribution of a large number of NOS and OT positive CSFCN with the great degree of coexistence in the region of the third ventricle might play an important role in modulating reproduction and sexual behavior by the hypothalamus-cerebrospinal fluid-hypophysis neuroendocrine regulation. (Figures 1～8 on plate 32)