骨骼肌组织对鸡胚背根节细胞GABA表达的影响

INFLUENCE OF SKELETAL MUSCLE ON THE EXPRESSION OFGABA IMMUNOREACTIVITY IN CHICK EMBRYO DRGZhou Changman△, Chen Biao, Wang Xuemin, Philippe E*

采用在体和离体实验及随后的免疫组织化学方法，研究了周围靶组织对鸡背根节（ＤＲＧ）内ＧＡＢＡ细胞发育的影响。在胚胎６ｄ行鸡胚单侧右后肢切除后１２ｄ，切除侧后肢缺如，其ＤＲＧ明显小于对照侧，其细胞数量也明显少于对照侧。实验侧的ＤＲＧ细胞均呈ＧＡＢＡ阴性，而对照侧有７．０％的感觉神经细胞为ＧＡＢＡ阳性。在Ｌ４～Ｓ１脊髓边缘切断右侧脊神经根后１２ｄ，ＤＲＧ的形态无特殊异常，ＧＡ－ＢＡ免疫反应细胞的出现率与对照侧相同。取自胚胎６ｄ的鸡胚ＤＲＧ细胞培养１２ｄ后的ＧＡＢＡ免疫反应为阴性。然而，当同样胚龄的ＤＲＧ细胞与骨骼肌细胞共同培养１２ｄ后，有部分ＤＲＧ细胞呈ＧＡＢＡ阳性反应，其神经突起与骨骼肌细胞相连。这些结果表明：鸡胚ＤＲＧ细胞ＧＡＢＡ的表达是依赖其周围靶组织——骨骼肌的存在，与其中枢靶组织无关。

he influence of peripheral target tissues skeletal muscle on the expression of GABA in the chick embryo dorsal root ganglia (DRG) was by studied both in vitro and in vivo. The results showed that in vivo the peripheral targets of sensory neurons were suppressed by excision of one hindlimb. After excision at E6, virtually all the ipsilateral dorsal root ganglia cells were free of GABA immunoreaction after 12days of reincubation. In contrast, the percentage of GABA immunoreactive ganglion cells was about 7% in control side. The central connections of L 4～S 1 spinal nerves in right side were transected at E6. After 12days deprivation of central connections, the percentage of GABA immunoreactive ganglion cells was the same as in control DRG at the same age. In vitro, the DRG cells cultured from E6, prior to formation of specific connection with peripheral target tissues were devoid of any GABA immunoreactive neurons even after 12 days of culture. Moreover, when the E6 DRG cells co cultured with skeletal muscular tissues for 12 dyas, some of the DRG cells were immunostained by GABA antiserum, and the terminal fibers of sensory neurons were observed connecting with muscular cells. These results indicate that initiation of GABA expression by sensory neurons requires interaction with skeletal muscle but not with spinal cord.