Elucidation of dopaminergic descending inhibitory passway by in vivo patch-clamp methods

采用全细胞膜片钳法研究了多巴胺（DA）对明胶质（SG）神经元的降压抗感觉作用。DA的应用诱导向外电流，抑制兴奋性突触后电流（EPSCs）的频率和幅度。结果表明，DA对皮肤的有害和无害刺激均产生直接抑制作用。此外，电刺激投射到脊髓的A11神经元可诱导向外电流并抑制EPSCs。这种效果与DA应用于SG神经元的情况类似。

We investigated the descending antinociceptive actions of dopamine(DA) on substantia gelatinosa(SG) neurons by in vivo whole-cell patch-clamp methods. The application of DA induced outward currents and suppressed the frequency and amplitude of excitatory postsynaptic currents(EPSCs). And it was showed that DA produced direct inhibitory effects in SG neurons to both noxious and innocuous stimuli to the skin. Furthermore, electrical stimulation of A11 neurons, which project to the spinal cord, induced outward current and suppressed of EPSCs. This effect is similar to the case of DA application to SG neurons.