Effects of neonatal dopamine depletion on pain mechanism in the adulthood

本研究的目的是通过行为学和组织学方法阐明新生儿多巴胺耗竭对成年期躯体感觉伤害反应和情绪反应的影响。新生多巴胺耗竭大鼠对化学刺激表现出行为性痛觉过敏反应，而对机械和热刺激没有反应。行为性痛觉过敏反应与脊髓神经元中持久的神经元过度活动有关。甲基苯丙胺治疗可以改善新生儿多巴胺耗竭引起的运动亢进，但不能逆转化学刺激引起的痛觉过敏反应。在一些行为测试中也观察到新生儿多巴胺耗竭大鼠焦虑相关行为的减少。这些结果表明，多巴胺能神经系统在表现正常伤害性和焦虑相关行为的机制发展中起着至关重要的作用。

The aim of this study is to clarify effects of neonatal dopamine depletion on somatosensory nociceptive response and emotional response in the adulthood using behavioral and histological methods. The rats with neonatal dopamine depletion exhibited behavioral hyperalgesic response to chemical stimulation, but not mechanical and thermal stimulation. The behavioral hyperalgesic response associated with long lasting neuronal hyperactivities in the spinal neuron. Treatment of methamphetamine, which ameliorates motor hyperactivity induced by neonatal dopamine depletion, did not reverse the hyperalgesic response to chemical stimulation. Decreases of anxiety-related behavior in the rats with neonatal dopamine depletion were also observed in some behavioral tests.These results suggest that dopaminergic neural system play a crucial part in development of mechanism for exhibiting normal nociceptive and anxiety-related behavior.