目的：探讨背侧海马CA1( dCA1)区5-HT2A受体的亚细胞定位及与谷氨酸NMDA受体空间关系，观测系统性激活5-HT2A受体对dCA1区主神经元和中间神经元放电频率的影响。方法采用包埋后免疫电镜技术，观测dCA1区神经元内5-HT2A受体和NMDA受体的分布，采用多通道记录技术，记录腹腔注射TCB-2激活5-HT2A受体后主神经元和中间神经元放电频率的变化。结果5-HT2A受体在海马dCA1区神经元的粗面内质网、线粒体等处广泛分布，并在突触、突触小泡和神经丝等处与 NMDA 受体共区域表达；激活5-HT2A受体可致dCA1区主神经元的放电频率明显升高，而对中间神经元的放电频率无明显影响。结论 dCA1区5-HT2A受体可能通过与NMDA受体的协同作用，以增加谷氨酸能神经元的兴奋性，从而达到促进学习和记忆的作用。%Aim To examine subcellular localization of serotonin 5-HT2A receptor (5-HT2AR) and glutamate NMDA receptor in dorsal hippocampal CA1 area ( dCA1 ) and further explore the effect of systemic acti-vation of 5-HT2A R on hippocampal neuronal firing rate. Methods The distribution of 5-HT2A R and NMDA re-ceptor in the dCA1 region was detected with immune e-lectron microscopy after embedding. The effect of acti-vation of 5-HT2A R on the principal neuron and inter-neuron firing rates was examined with multichannel re-cording. Results 5-HT2A R immunoreactivity was ob-served in the dCA1 neurons, including rough endoplas-mic reticula and mitochondria, and the 5-HT2A R and glutamate NMDA receptors were colocalized in the syn-aptic membrane, vesicle and neurofilament of the hipp-ocampal neuron. 5-HT2A R activation increased princi-pal neuronal firing rate and the interneuronal firing rate was not changed. Conclusion The 5-HT2A R and NM-DA receptor are colocalized in dCA1 neurons, and acti-vation of 5-HT2A R increases hippocampal principal neuronal firing rate.
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