INCREASE OF LOCOMOTOR-ACTIVITY BY ACUPUNCTURE ON BAI-HUI POINT IN RATS

The effect of acupuncture on locomotor activity was investigated in ra ts. Stimulation with acupuncture inserted in Bai-Hui point, which is l ocated at the vertex of the head, increased the spontaneous locomotor activity of rats measured in ANIMEX meter. This effect was obtained in rats which received acupuncture significantly at 60 min later as comp ared with sham-treated control. The sleeping time induced by hexobarbi tal was also reduced markedly in rats receiving acupuncture. An activa tion of the central nervous system by acupuncture at Bai-Hui point can thus be considered. This action was unrelated to opioids because nalo xone failed to modify it. Increase in locomotor activity was abolished by an intraperitoneal (i.p.) injection of a-methyl-p-tyrosine (200 mg /kg) at 2 h before insertion of acupuncture. Deprenyl at the dose suff icient to elevate monoamine enhanced this action of acupuncture. Media tion of cerebral monoamines can also be considered. This view was supp orted by the dose-dependent inhibition of chlorpromazine. Action of ac upuncture was not observed in apomorphine (0.5 mg/kg, i.p.)-treated ra ts, probably due to an activated receptor of dopamine. Otherwise, acti on of acupuncture was enhanced by para-chlorophenylalanine, the deplet er of endogenous 5-hydroxytryptamine (5-HT), and eliminated by 5-hydro xytryptophan, the precursor of 5-HT, in the initial stage of insertion . Participation of 5-HT can be considered as an initial way in rats th at received acupuncture at Bai-Hui point. These results suggested that stimulation of Bai-Hui point with acupuncture can activate central ne urotransmission of monoamines to increase the spontaneous locomotor ac tivity in rats.