关键词: 甲基苯丙胺；多巴胺；神经元；超极化激活阳离子电流；大鼠 

Abstract: Objective  To label and identify the mesolimbic dopaminergic neurons and observe the effects of high concentration methamphetamine (MA) on their electrophysiological properties and hyperpolarization-activated cation current(Ih). Methods  Fluorescent retrograde tracer was injected into nucleus accumbens (NAc) with stereotaxic apparatus. The labeled cells were identified with tyrosine hydroxylase (TH) immunohistochemical staining. Whole-cell patch-clamp recordings were prepared from the labeled neurons in brain slices with and without MA (10μmol/L) treatment. Results  Mesolimbic neurons projected to NAc were successfully labeled with fluorescence tracer. Immunohistochemical staining showed that labeled cells were TH positive, which mainly distributed in the ventral tegmental area (VTA). The spontaneous action potential frequency of labeled neurons was obviously reduced by MA treatment (P<0.05). Besides, the Ih current was obviously inhibited (P<0.05) by MA.  Conclusion  MA inhibits the spontaneous action potential frequency and Ih of mesolimbic dopaminergic neurons.

Key words: Methamphetamine, Neurons, Dopamine, Hyperpolarization-activated cation current, Rats