β-Endorphin- and GABA-mediated depressor effect of specific electroacupuncture surpasses pressor response of emotional circuit

It has been proved that input of specific electroacupuncture (EA) can activate beta -endorphin(beta -EP)ergic and noradrenergic neurons projecting to the rostra[ ventrolateral medulla (RVL), the latter acting upon the RVL-GABAergic interneurons, thereby produce depressor effect. The present study further shows that: (1) The EA depressor effect is strong enough to surpass the pressor response of the AC (nucleus amygdaloideus central is) -emotional circuit, (2) both beta -endorphin (beta -EP) and GABA in the RVL mediate the EA antagonistic effect, (3) the EA effect does not take place in the AC and paraventricular nucleus (two key nuclei besides the RVL, which also have beta -EPergic input) in the emotional circuit. (C) 2001 Elsevier Science Inc. All rights reserved.