红核在大脑皮质下行调控脊髓伤害感受性传递中的作用

以电刺激外周感受野诱发的大鼠脊髓背角WDR和NS神经元的晚串放电（C-反应）为指标,以串脉中刺激对侧大脑脚（CP）作为条件刺激,在C-反应受到明显抑制的神经元。分别观察了电解损毁红核（RN）和RN内注射兴奋性氨基酸的受体拮抗剂对刺激CP的下行抑制作用的影响。结果发现：损毁同侧RN后,刺激CP对C反应的抑制作用明显减弱,而损毁同侧RN背侧结构,对侧RN及假损毁RN均无此效应;RN内微量注射兴奋性氨基酸受体拮抗剂AP5和DNQX均可减弱刺激CP对C-反应的抑制。提示RN至少部分参与大脑皮质对脊髓伤害感受性传递的下行抑制作用。且以同侧RN为主;在与痛觉调制有关的皮质-RN通路中既有NMDA受体又有非NMDA受体的参与。

Role of the red nucleus in cortical inhibition of spinal nociceptive transmission

The long latency responses (C-fiber evoked responses) of the wide dynamic range (WDR) and nociceptive specific (NS) neurons in the rat spinal cord dorsal horn to cutaneous electrical stimulation were used as nociceptive responses. Inhibition of the C-responses was elicited by conditioning stimulation of the contralateral cerebral peduncle (CP) with train pulses. Effects of electrolytic lesion of the red nucleus (RN) and microinjection of excitatory amino acid receptor antagonists into the RN on the CP-stimulation-induced inhibition were observed. The results indicated that lesion of the ipsilateral RN attenuated the inhibition of C-responses produced by CP stimulation. However, lesion of the adjacent structures dorsal to RN, the contralateral RN and sham lesion had no such effect. After microinjection of AP5 and DNQX into the ipsilateral RN, the CP-stimulation-induced inhibition was reduced. It is suggested that RN is involved, at least in part, in the cortical inhibition of spinal nociceptive transmission, and both NMDA and non-NMDA receptors take part in mediating this descending inhibition in the RN level.