Objective To estimate the effect of the NO on the medial amygdaloid nucleus(Me), we studied the origins of the NOS positive terminals in the Me. Methods Noergic afferent projection to Me was identified by a combined NADPH-d histochemical staning and retrograde CTb immunocytochemical method after microinjecting CTb into Me. Results The double labeled of neurons (NOS and CTb) were located in dorsal raphe nucleus, locus ceruleus, basolateral amygdaloid nucleus, parabrachial nucleus, ventrolateral part of p...