刺激大鼠下丘脑背内侧核对丘脑束旁核痛相关神经元放电的影响

本文在 79只清醒麻痹大鼠身上,用玻璃微电极记录丘脑束旁核痛兴奋(PfPE)和痛抑制(PfPI)单位的放电及其对刺激下丘脑背内侧核(DMH)的反应,并观察切割脊髓背外侧束的效应。主要结果如下:(1)刺激DMH使PfPE 单位的自发放电及痛放电有明显的抑制作用,而使PfPI 单位的自发放电增多,并解除伤害性刺激引起的抑制效应;(2)刺激DMH引起PfPE 单位的抑制效应,在切割脊髓背外侧束后仍然出现。上述结果提示:DMH 对丘脑束旁核在处理痛觉信息上具有调制作用,这种调制作用可能不通过脑干下行性抑制系统完成,而主要是通过脊髓上联系抑制丘脑束旁核神经元对痛传入的反应。

EFFECT OF STIMULATION OF THE HYPOTHALAMIC DORSOMEDIAL NUCLEUS ON THE DISCHARGES OF PAIN-RELATED NEURONS IN THE PARAFASCICULAR NUCLEUS OF RATS

The effects of the hypothalamic dorsomedial nucleus (DMH) stimulation on thedischarges of pain-related neurons in the parafascicular nucleus of 79 conscious andcurarized rats were examined with glass microelectrodes. The effects of sectionof dorsolateral funiculus (DLF) of the spinal cord were studied. The main resultswere as follows: (1) The spontaneous and nociceptive discharges of pain-excitatoryunits of parafascicular nucleus (PfPE) were profoundly inhibited, the spontaneousdischarges of pain-inhibitory units of parafascicular nucleus (PfPI) were incrasedwhile their nociceptive inhibition were released by the stimulation of DMH;(2) Theinhibitory effects of stimulation of DMH on PfPE remained unchanged after cuttingDLF of the spinal cord. The results mentioned above suggest that DMH playsa modulatory action on the integration of painful information in Pf and that thismodulation may be carried out via supraspinal pathways without the participa-tion of brain stem descending inhibitory pathways.