楔状核内促甲状腺激素释放激素抗伤害感受机制探讨

INVESTIGATION OF THE MECHANISM OF THE ANTINOCICEPTIVE ROLE OF THYROTROPIN-RELEASING HORMONE IN NUCLEUS CUNEIFORMIS

目的 :探讨楔状核 ( NCF)内促甲状腺激素释放激素 ( TRH)抗伤害感受作用的机制。方法 :用玻璃微电极细胞外记录结合核团微量注射的方法 ,于延髓中缝大核 ( NRM)内记录痛兴奋神经元 ( PEN)的单位放电 ,观察中脑导水管灰质 ( PAG)内注射纳络酮对 NCF内注射 TRH对 NRM内 PEN的痛放电影响。结果 :PAG内预先注射纳络酮 ( lμg/0 .5μl)能部分阻断 NCF内 TRH对 NRM内 PEN痛放电抑制效应。结论 :TRH在 NCF内的抗伤害感受作用与阿片受体有关 ,并可能通过下行镇痛通路实现。

Objective:To investigate the mechanism of the antinociceptive role of thyrotropin releasing hormone in nucleus cuneiformis.Methods:Using the extracellular recording with microinjection of nucleus,we recorded the frequencies of evoked discharge of pain excitative neurons (PEN) in nucleus raphe magnus(NRM) to investigate the mechanism of the antinociceptive role of thyrotropin releasing hormone (TRH) in nucleus cuneiformis(NCF).Results:Intra PAG preinjection of naloxone(1 μg/0 5 μl,n=9)could partially antagonise the inhibitory effect of intra NCF of TRH on the frequency evoked discharge of PEN in NRM.Conclusion:Some neurons in NCF might participate in the process to modulate noxious information transmission in CNS.TRH might be a neuromodulator or transimitter in the antinociception of NCF and the effect of TRH may be mediated by opioid receptor.