[Possible mechanisms of amygdala participation in the regulation of gastric motor activity].

Mechanisms of the amygdala central nucleus (CNA) influence on gastric motor reflex activity were studied in electrophysiological and neuroanatomical experiments in Wistar rats. In the anaesthetized animals, electrical stimulation of the CNA affected spontaneous gastric motility and caused inhibitory as well as excitatory changes of vagus-induced gastric relaxation. The most significant and mainly inhibitory effects were observed under the stimulation of the medial CNA. Microinjection of the anterograde tracer Phaseolus vulgaris-leucoagglutimn (PHA-L) into the different divisions of the CNA revealed direct projections from its dorso-medial portion to the gastric related area of the dorsal vagal complex. Electrical stimulation of this amygdaloid area was found to change activity of the bulbar gastric related neurons. Inhibitory and excitatory changes of their vagus-induced responses under the amigdala stimulation were manifested as a general modulation of all phases of the reaction or a selective modulation of some of them. These mechanisms may underlie the amygdalo-fugal modulation of gastric motor reflex activity.