低渗刺激后大鼠视上核内星形胶质细胞和神经元的可塑性改变及其相互关系

为观察低渗刺激后大鼠视上核(SON)内星形胶质细胞和神经元的可塑性反应及其两者在反应时间和空间上的相互关系,我们采用大鼠尾静脉注射 5. 5ml/kg低渗盐水(0. 83% 葡萄糖+ 0. 3% NaCl)制作模型,应用抗Fos、抗胶质原纤维酸性蛋白(GFAP)单标记,以及抗Fos/抗GFAP双标记、抗Fos/抗血管加压素 (VP) /抗GFAP三标记的免疫组化方法。结果发现:在SON中GFAP阳性星形胶质细胞数量在刺激后 15min增加,其胞体肥大,突起伸长变粗, 45min达高峰。Fos阳性星形胶质细胞胞核呈蓝黑色小点,刺激后 15~45min达高峰, 90min明显减少;Fos阳性神经元胞核较大,刺激后 15min未见表达, 45min少量表达, 90min表达增加。该结果表明低渗刺激后,SON内星形胶质细胞的Fos表达早于神经元,三重标记显示星形胶质细胞与神经元关系密切,提示SON内星形胶质细胞可能在低渗刺激的调节中发挥一定作用。

THE CHANGES OF PLASTICITY AND RELATIONSHIP OF ASTROCYTES AND NEURONS IN SUPRAOPTIC NUCLEUS AFTER HYPO-STIMULATION

By using single labeled, double labeled and triple labeled immunohistochemical techniques, we observed the plastic response of astrocytes and neurons in SON to hypoosmotic stimulation by injection 5.5 ml/kg hypo-saline (0.83% glucose plus 0.3% NaCl) into the caudal vein, and their temporal/spatial relationship. The results showed that the number of GFAP-like immunoreactive (LI) astrocytes in SON increased at 15 min after stimulation, and peaked at 45 min. At the same time ,their bodies hypertrophied, the processes thickened. Fos-LI nuclei of astrocytes were deep-blue dots, and they expressed most during 15～45 min, then significantly decreased from 90 min. Fos-LI nuclei of neurons appeared at 45 min, peaked at 90 min. The present study demonstrated that the expression of Fos-LI nuclei in astrocytes was earlier than that in neurons of SON. The results showed there was close relationship between the astrocytes and neurons, which indicated that astrocytes may be involved in regulation of hypo-stimulation.