Neuroscience Research Institute, Peking University, China.
Addict Biol. 2009 Sep;14(4):431-7. doi: 10.1111/j.1369-1600.2009.00163.x. Epub 2009 Jun 1.
Chronic morphine administration decreases the size of dopamine (DA) neurons in the ventral tegmental area (VTA). These transient morphological changes are accompanied by a reduced sensitivity of morphine-induced conditioned place preference (CPP) after chronic exposure to the drug. In this study we examined alterations in the firing rate of DAergic neurons by means of extracellular recording following chronic morphine exposure and applied 100 Hz electroacupuncture (EA) treatment to reverse the reduced firing rate of these neurons. In the first set of experiments we show that in rats, which received chronic morphine treatment for 14 days, a small dose of morphine was not able to induce a CPP response anymore. However, the sensitivity to morphine was reinstated by consecutive EA treatment for 10 days. The electrophysiological response of VTA DA neurons to morphine was markedly reduced in chronic morphine-treated rats compared to saline-treated controls. A substantial recovery of the reactivity of VTA DA neurons to morphine was observed in rats that received 100 Hz EA for 10 days. Our findings suggest that 100 Hz EA is a potential therapy for the treatment of opiate addiction by normalizing the activity of VTA DA neurons.
慢性吗啡给药会导致腹侧被盖区（VTA）中多巴胺（DA）神经元的体积减小。这些短暂的形态变化伴随着慢性暴露于药物后，吗啡诱导的条件位置偏好（CPP）的敏感性降低。在这项研究中，我们通过慢性吗啡暴露后的细胞外记录来检查 DA 能神经元的放电率变化，并应用 100 Hz 电针（EA）治疗来逆转这些神经元的放电率降低。在第一组实验中，我们表明，在接受 14 天慢性吗啡治疗的大鼠中，小剂量的吗啡不再引起 CPP 反应。然而，连续 10 天的 EA 治疗恢复了吗啡的敏感性。与生理盐水处理的对照组相比，慢性吗啡处理的大鼠 VTA DA 神经元对吗啡的电生理反应明显降低。在接受 100 Hz EA 治疗 10 天的大鼠中，观察到 VTA DA 神经元对吗啡的反应性有了很大的恢复。我们的研究结果表明，100 Hz EA 是一种通过使 VTA DA 神经元的活动正常化来治疗阿片类药物成瘾的潜在疗法。
