按祖国医学理论

针刺怍为外因

通过体内各调节系统产生效应.针刺镇痛则是通过激活和加强体内的抗痛系统而实现。在吗啡镇痛的研究中

提出脑内存在抗痛系统

脑室—导水管周围灰质(PAG)是吗啡镇痛的高效区

富有阿片受体及脑啡肽神经元

微量注入吗啡或电刺激PAGIn our previous work

it has been shown that PAG

rich in opiate receptors and enkephalins

might play a critical role in acupuncture analgesia. In the present work the effect of acupuncture on spontaneous and noxious-evoked response in PAG and its relation to enkephalins were in vestigated by the technique of iontophoresis. There were four types of response in spontaneous neuronal discharge to acupuncture applied to Zusanli points: no response (3/53)

excitatory Present Address: Beijing Capital Hospital. Yiantai district Institute of Medicine

Shandong response (7/53)

excitatory response followed by inhibitory response(40/ 53) and inhibitory response (3/53). The increase of the firing rate of most neurons(47/53)in PAG suggests that PAG may be activated by acupuncture. The inhibitory effect by acupuncture

including the inhibitory response following pre excitatory response

was reversed in most neurones (20/24) by naloxone applied iontophoretically. It is assumed that the endogenous morphine like sudstance released by activation of PAG and other related structures may be involved in the inhibitory response mediated by a negative feed back regulation. The PAG nociceptive response

either strengthened or weakened by morphine applied iontophoretically

were attenuated by acupuncture in most cases. It is postulated that the activation of the descending inhibitory pa thway to block the transmission of nociceptive information may play an important role in acupuncture analgesia.