Zhen Ci Yan Jiu. 1990 ; 15(1): 61-5.

[Relationship between the precruciate cortex and the ventral lateral posterior nucleus of the thalamus in acupuncture analgesia]

Chen Z, Yan Y, Xu W, Shi T.

Institute of Acupuncture and Moxibustion, China Academy of Traditional Chinese Medicine, Beijing.

The present study was designed to investigate the relationship between the precruciate cortex (PreCtx) and the ventral lateral posterior nucleus (VPL) of the thalamus in the mechanisms of acupuncture analgesia. Neuronal responses in the nucleus VPL to electrical noxious stimulation of the superficial peroneal nerve were extracellularly recorded. Lidocaine was topically applied at PreCtx. Twenty minutes after the application electroacupuncture (EA) was employed at "Zusanli" and "Huantiao" points for 5 minutes. The nociceptive responses were recorded immediately after cessation of EA and consecutively recorded at the interval of 2 minutes. Similar procedures were made in the control group, in which 0.9% Nacl was topically applied at PreCtx. It was found that topical application of lidocaine at PreCtx did not influence the nociceptive responses of VPL neurons. Following topical application of lidocaine at PreCtx, the nociceptive responses were obviously inhibited 0', 4', 6', 10', and 12' after cessation of EA. In the saline control group the remarkable inhibitory effect of EA was observed 0'-8' after ceasing EA, The results showed that the inhibitory effect of EA in the test group was weaker than that in the control group. However, the difference was not statistically significant. It is suggested that PreCtx participates in the corticofugal modulation of EA effects in the nucleus VPL only to small extent.