Some pharmacological observations on the analgesia induced by acupuncture in rabbits.

(1) The characteristics of an analgesia which can be elicited in rabbits by electrically activated acupuncture needles are described. (2) The analgesia can be reversed by systemic administration of the inhibitory amino acid antagonists bicuculline or strychnine. (3) Pharmacological procedures which interfere with tryptaminergic mechanisms, or destruction of the dorsal raphe nuclei, prevent the development of analgesia. (4) It is concluded that the production of analgesia probably depends upon postsynaptic inhibition of the transmission of afferent information from nociceptors, and at more than one site in the central nervous system.