GABA对小鼠大脑皮质中GABA受体胚胎发育的调节

本文用ＧＡＢＡ及其受体激动剂和拮抗剂处理培养的胚胎小鼠大脑皮层神经细胞以及精确计时的妊娠小鼠，用放射配体结合法检测ＧＡＢＡＡ及ＧＡＢＡＢ的结合位点数目，研究了ＧＡＢＡ对小鼠大脑皮层ＧＡＢＡ受体胚胎发育的调节作用，结果表明：①ＧＡＢＡ可使培养１５—１７天妊龄的胚胎小鼠大脑皮层神经细胞及出生第１天的仔鼠大脑皮层中的ＧＡＢＡＡ及ＧＡＢＡＢ受体数目增加，这种作用可被蝇蕈醇（Ｍｕｓ）及巴氯芬（Ｂａｃ）分别模拟，对ＧＡＢＡＡ受体的作用可为荷包牡丹碱（Ｂｉｃ）所阻断；②用ＧＡＢＡ处理妊娠７—１３天的小鼠，仔鼠出生第１天其大脑皮层的ＧＡＢＡＡ及ＧＡＢＡＢ受体数目均无变化；③用ＧＡＢＡ处理妊娠１４—１９天的小鼠，仔鼠出生的第１天其大脑皮层中的ＧＡＢＡＡ受体数目增加而ＧＡＢＡＢ受体数目不变；④用ＧＡＢＡ处理妊娠７－１９天的小鼠，仔鼠出生第１天其大脑皮层中ＧＡＢＡＡ及ＧＡＢＡＢ受体数目增加。这说明在胚胎发育的特定时期内，ＧＡＢＡ可诱导其受体数目的增加，这个作用是由ＧＡＢＡ受体调节的。

THE REGULATION OF GABA ON DEVELOPMENT OF GABA RECEPTORS IN EMBRYONIC MICE CEREBRAL CORTEX

In order to investigate the regulation of GABA on development of GABA receptors in embryonic mice cerebral cortex,GABA and giands were used to treat the embryonic mouse cerebral cortex cells(EMCC) in culture and embryonic mice GABA receptors were measured by radio giand binding method The results showed that:1) GABA could increase in the number of GABA A and GABA B receptors of EMCC of 15-17 day embryonic mouse in culture and postnatal day 1(PN 1) mouse cerebral cortex in vivo ,and this effect could be mimicked by muscimol and baclofen,and blocked by bicuculline 2) Treated with GABA from embryonic day 7 to 13,the number of GABA A and GABA B receptors of PN 1 mice cerebral cortex remained unchanged 3) Treated with GABA from embryonic day 14 to 19,the number of GABA A receptor of PN 1 mice cerebral cortex increased,but that of GABA B receptor remained unchanged 4) Treated with GABA from embryonic day 7 to 19,the number of GABA A and GABA B receptors of PN 1 mice cerebral cortex increased significantly The results suggested that GABA could promote the expression of GABA receptors in special stage of embryonic development, and this action was mediated by GABA receptors