海马体神经元内源性大麻素Ⅰ型受体与小清蛋白共表达的研究

Study on Co-Expression of Cannabinoid Receptor 1 with Parvalbumin in the Hippocampal Neurons

内源性大麻素系统广泛分布于哺乳动物的中枢神经系统中,参与调节多种生理过程和行为反应。其中,大麻素Ⅰ型受体(Cannabinoid Receptor 1,CB1R)大量分布在表达生长激素抑制素、胆囊收缩素、多巴胺、5-羟色胺等神经递质受体的神经元末梢上。CB1R激活可抑制突触前膜神经递质的释放,逆行调控神经元的兴奋性。然而,对于中枢神经系统中另一类具有重要抑制性作用的小清蛋白(Parvalbumin,PV)阳性的γ-氨基丁酸能中间神经元是否表达CB1R,却鲜有报道。该文利用免疫荧光染色和激光共聚焦成像技术发现,小鼠海马体少量神经元存在PV与CB1R共表达,且PV/CB1R阳性神经元在海马体中的分布无雌雄差异。该结果能为进一步阐明PV与CB1R在功能上的相互作用提供一定参考价值,也将有助于更全面地了解内源性大麻素系统的调控作用。

The endocannabinoid system,which widely distributes in the mammalian central nervous system,is involved in regulating a variety of physiological processes and behavioral responses.Cannabinoid receptorⅠ(CB1R)is abundantly localized on the neuronal synapse terminals that expresses various receptors of neurotransmitters,such as somatostatin,cholecystokinin,dopamine and serotonin.Activation of CB1R inhibits the release of presynaptic neurotransmitters,and retrogradely controls neuronal excitabilities.However,there are few reports on the expression of CB1R in parvalbumin(PV)positive gamma-aminobutyric acid interneurons in the central nervous system.In this study,immunofluorescence staining and laser confocal imaging techniques were used to identify the PV+and CB1R+cell in the hippocampus.We found that a small number of neurons in the hippocampus of male and female CB1R-iCre-EGFP mice were co-expressed with PV and CB1R.Moreover,there was no sex difference of the distribution of PV+/CB1R+neurons.These results could provide a reference value for further elucidating the functional interaction between PV and CB1R,and also contribute to a more comprehensive understanding of the regulatory role of endocannabinoid system.