单次可卡因注射对VTA区DA神经元兴奋性突触传递和内在兴奋性的影响

THE INFLUENCE OF SINGLE COCAINE EXPOSURE ON EXCITATORY SYNAPTIC TRANSMISSION AND INTRINSIC EXCITABILITY OF DOPAMINERGIC NEURONSIN VENTRAL TEGMENTAL AREA

目的:研究单次可卡因注射24 h后VTA区多巴胺能(DA)神经元兴奋性突触传递强度和内在兴奋性的变化。方法:采用离体膜片钳技术,检测单次可卡因注射24 h后VTA区DA神经元自发性慢性内向流(slow inwardcurrents,SICs)、内在兴奋性以及兴奋性突触后电流(EPSCs)的变化。结果:DA神经元的SICs、内在兴奋性和EPSCs均有显著增强。结论:单次可卡因注射后VTA区DA神经元兴奋性突触传递强度和内在兴奋性呈现协同增强效应。

Objective：To investigate the modulation of cocaine exposure on synaptic plasticity and plasticity of neuronal intrinsic excitability of dopaminergic（DA）neurons in ventral tegmental area（VTA）.Methods：In this study,by using in vitro patch-clamp technique,we observed the effects of single cocaine injection on slow inward currents（SICs）,intrinsic excitability and excitatory postsynaptic currents（EPSCs）of DA neurons in VTA.Results：The SICs,intrinsic excitability,and ratio of α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptors to N-methyl-D-aspartate receptors（AMPAR/NMDAR）mediated currents of DA neurons were significantly enhanced 24 hours after single cocaine injection.Conclusion：There is a synergistic mechanism between synaptic plasticity and plasticity of neuronal intrinsic excitability after single cocaine exposure which might be response to neuron adaptation associated with drug addiction.