杏仁核-海马nesfatin-1对大鼠胃牵张敏感神经元放电活动影响

EFFECTS OF AMYGDALA-HIPPOCAMPUS NESFATIN-1 ON ELECTRICAL ACTIVITY OF GASTRIC DISTENSION SENSITIVE NEURONS

目的探讨杏仁核nesfatin-1对大鼠胃牵张（GD）敏感神经元放电活动的影响及调控。方法健康成年雄性Wistar大鼠116只,中央杏仁核微量注射nesfatin-1、黑皮质素受体拮抗剂SHU9119及生理盐水,并应用单细胞外电生理记录的方法观察杏仁核内GD神经元放电活动的变化;电刺激海马CA1区,探讨杏仁核-海马神经通路对杏仁核GD敏感神经元放电活动的调控作用。结果 116只大鼠胃扩张刺激后,在中央杏仁核共记录到192个GD敏感神经元,其中114个（59.4%）为GD兴奋性（GD-E）神经元,78个（40.6%）为GD抑制性（GD-I）神经元。杏仁核微量注射nesfatin-1,52个GD-E神经元中有36个神经元（69.2%）呈现兴奋效应（t=9.62,P〈0.01）;在30个GD-I神经元中,有22个神经元（73.3%）呈现抑制效应（t=3.48,P〈0.01）。黑皮质素受体拮抗剂SHU9119可部分阻断nesfatin-1对杏仁核内GD神经元的兴奋或抑制效应（t=6.43~7.14,P〈0.01）;在42个对nesfatin-1有兴奋反应的GD-E神经元中,电刺激海马CA1区可使24个（57.1%）神经元呈现兴奋效应（t=6.92,P〈0.01）;杏仁核内微量注射SHU9119后再电刺激海马CA1区,其中有29.2%（7/24）的神经元放电频率显著降低（t=2.13,P〈0.05）。在电刺激海马CA1区后产生兴奋效应的14个GD-I神经元中,杏仁核内微量注射SHU9119后再电刺激海马CA1区,其中有4个神经元（28.6%）的放电频率显著增加（t=2.20,P〈0.05）。结论杏仁核-海马nesfatin-1通路参与杏仁核GD敏感神经元放电活动调控,该作用可能与黑皮质素信号系统有关。

Objective To explore the effects of nesfatin-1in amygdale on electrical activity of gastric distension（GD）sensitive neurons and its regulation. Methods This study consisted of 116 adult male Wistar rats.Microinjection of nesfatin-1,melanocortin receptors antagonist SHU9119,and normal saline to the central nucleus of amygdala（CeA）was done.Employing cell electric physiological recording method,the changes of discharge activity of GD sensitive neurons in the CeA were observed.Electrical stimulation of hippocampal CA1 area was done to investigate the regulation of CeA-hippocampal neural pathways on electrical activity of GD sensitive neurons. Results After stomach dilatation in 116 rats,192GD sensitive neurons were recorded in the CeA,of which,114（59.4%）were GD excitatory neurons（GD-E）and 78（40.6%）were GD inhibitory neurons（GD-I）.After microinjection of nesfatin-1in CeA,36 of 52（69.2%）GD-E neurons were excited（t=9.62,P〈0.01）,and 22 of 30（73.3%）GD-I neurons were inhibited（t=3.48,P〈0.01）.Melanocortin receptors antagonist SHU9119 could partially block the exciting or inhibiting effects induced by nesfatin-1on CeA GD neurons（t=6.43-7.14,P〈0.01）.In 42 CeA nesfatin-1exciting GD-E neurons,57.1%（24/42）were excited after electrical stimulation of hippocampal CA1area（t=6.92,P〈0.01）.After microinjection with SHU9119 in CeA followed by electrical stimulation in hippocampal CA1,29.2%（7/24）of the neurons discharge frequency decreased significantly（t=2.13,P〈0.05）.In 14GD-I neurons showed excitation after electrical stimulation in hippocampal CA1 areas,microinjection of SHU9119 in CeA and once again electric stimulating CA1 areas,the frequency of discharge in four（28.6%）GD-I neurons notably increased（t=2.20,P〈0.05）. Conclusion Amygdale-hippocampus nesfatin-1neural pathway involves in regulating discharge activity of gastric distension sensitive neurons,and this effect may be associated with melanocortin signalling.