GABA参与兔杏仁体抑制内膝体神经元电活动

本文采用多管微电极胞外记录技术观察了短纯音引起兔内膝神经元的声反应及刺激杏仁体对声反应的影响,并在此基础上观察电泳ＧＡＢＡ及其拮抗剂Ｂｉｃｕｃｕｌｌｉｎｅ的效应。实验结果表明：ＧＡＢＡ可以抑制ＭＧＢ神经元的声反应及自发放电活动,而ＧＡＢＡＡ拮抗剂Ｂｉｃｕｃｕｌｌｉｎｅ的作用则相反;电泳ＧＡＢＡ对ＭＧＢ神经元产生同刺激杏仁体一样的抑制产应,并且这种影响可被Ｂｉｃｕｃｕｌｌｉｎｅ翻转;嗅鼻沟后缘听区农

GABA mediated inhibitory effect of amygdala on the activity of medial geniculate body neurons

On 10 New Zealand white rabbits immobilized with Flaxedil, the inhibitory effect of amygdaloid stimulation on the responses of medial geniculate body (MGB) neurons to tone bursts and the involved neurotransmitter mechanism were investigated with microiontophoresis technique. The results showed that application of GABA could cause a suppression of spontaneous activity of MGB neurons while GABAA antagonist bicuculline had an opposite effect. Iontophoretic injection of GABA gave an inhibitory effect on MGB neurons similar to that caused by stimulating the amygdala or the auditory cortex behind the rhinal sulcus (ACBRS), and in particular, the GABA induced suppression could be completely antagonized by application of bicuculline. Taken together, these data suggested that GABA mediated the amygdaloid inhibitory effect. It seemed unlikely that glycine was involved in the effect, since strychnine, a glycine antagonist, could not affect the descending inhibition from ACBRS area.