大鼠丘脑中央下核神经元对针刺的反应

RESPONSES OF NEURONS IN THALAMIC NUCLEUS SUBMEDIUS TO ACUPUNCTURE IN THE RAT

本文采用玻璃微电极细胞外记录的方法，观察了大鼠丘脑中央下核（Sm）神经元对针刺的反应。对手针刺激反应的神经元一般地也对伤害性皮肤或肌肉刺激发生反应，提示针刺与伤害性机械刺激具有相同或相似的属性，Sm可能在针感形成及针刺镇痛的中枢机制中起重要作用。本研究为脊髓-Sm－VLO－PAG-脊髓痛调制负反馈环路参与针刺镇痛，尤其是细纤维镇痛的设想提供了支持。

The experiments were conducted on 23 anesthetized rats. The single unit activity was recorded extracellularly from thalamic nucleus submedius (Sm) with a glass micropipette, and the responses of neurons in Sm to acupuncture were observed. The results showed that most of the neurons in Sm resPOnded to needle acupuncture. In general the neurons which responded to needle acupuncture also responded to noxious cutaneous or muscle stimuli, suggesting that the properties of the needle acupuncture are similar to those of the noxious mechanical stimulation. The Sm probably plays an important role in the formation of the needling sensation and the central mechanism of acpuncture analgesia. Results of this study provide support for the assumption that the spinal cord-Sm-VLO(ventral lateral orbital cortex)-PAG-spinal cord negative feedback circuit for nociceptive modulation participates in the acupuncture analgesia, especially in that produced by activation of the small afferent fibers.