阻断缰核对伏核注射TRH抑制丘脑束旁核痛放电的影响

用细胞外记录神经元单位放电和核团微量注射法,观察了阻断缰核对伏核注射促甲状腺素释放激素(TRH)抑制大鼠丘脑束旁核痛兴奋性神经元(PEN)痛放电的影响。结果表明,向缰核分别预先注射2％利多卡因(0.5μl)、氟哌啶醇(2.5μg/μl)均可明显减弱伏核注射TRH对束旁核PEN痛放电的抑制作用。而在缰核内分别预先注射纳洛酮(5μg/μl)、阿托品(10μg/μl)则不影响伏核注射TRH抑制束旁核PEN痛放电的作用。以上结果提示,缰核是伏核下行性抑制的一个中继站,TRH在伏核的抗伤害性感受作用可能下行通过缰核内的多巴胺能神经元完成。

The Influence of Habenula Blocking on the Effect of Pain Discharges Inhibition of Nucleus Farafascicularis by Injection of TRH into the Nucleus Accumbens

Extracellular recording and microinjection methods were used to investigate the influence of habenula nucleus blocking on the effect of inhibition of pain discharges of nucleus parafascicularis (PF) by injection of Thyrot-ropin-Releasing Hormone (TRH) into the nucleus accumbens. The results showed that preinjtction of Lidocaine into nucleus habenula could strikingly decrease the inhibition effect of pain discharges of PF byinjecting TRH into nucleus accumbens, and so could Preinjection of Holoperidol into nucleus habenula. However, Preinjection of Naloxone or Atropine did not affect the effect of TRH-injec-tion. These results suggest that there is a pain modulation pathway from nucleus accumbens to nucleus habenula, and TRH exerts its inhibitory action on pain perception through the dopaminergic neurons in nucleus habenula.