Zhen Ci Yan Jiu. 1990 ; 15(1): 77-81, 29.

[Changes in responses of parafascicular nuclei during adjuvant-induced acute arthritis and effect of acupuncture in the rat]

Xu Z, Xu W, Chen Z.

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

We have previously demonstrated that during acute arthritis in the rats induced by local intraplanter adjuvant, there are dramatic alterations in the behavioral responses to noxious stimulation. The purpose of this study was to observe the changes in responses of parafascicular nuclei (Pf) neurons during acute arthritis and effect of acupuncture (EA) in the rats. It was shown that: (1). for the whole populations of somatosensory neurons there was no statistical significant between arthritic rat and normal rat (P greater than 0.05). However, nociceptive neurons activated exclusively by noxious stimulation were less in the arthritic rat (21/60) than in the normal rat (35/46) (P less than 0.01); nociceptive-non-nociceptive neurons activated by both noxious and non-noxious stimulation were more in the arthritic rat (30/60) than in the normal rat (9/46) (P less than 0.01), and there was no statistical significant different for population of non-nociceptive neurons between two groups. (2). Nociceptive responses of Pf neurons (n = 16) could be markedly inhibited by EA at Xuanzhong (G39) and Kunlun (B60) in acute arthritic rat. In particular, the inhibitory effect was of great significance (P less than 0.01) during 0-10 and 20-35 minutes following cessation of EA. These results suggest that rats were hyperalgesic during adjuvant-induced acute arthritis and EA produces a fine analgesic effect in acute arthritic rats. The results also support the view that adjuvant-induced acute arthritic rat can be considered as a model for research of pain and analgesia.