Anxiogenic-like action of galanin after intra-amygdala administration in the rat

The neuropeptide galanin is expressed in brain structures implicated in reg ulation of emotionality. The amygdala is known to play a central role in me chanisms of fear and anxiety. We therefore examined the effects of galanin (0.2 and 0.6 nmol/side) on experimental anxiety upon microinjection into th e amygdala. Two established animal models of anxiety were used: a punished drinking test, and the elevated plus-maze. Punished responding was dose dep endently suppressed by intra-amygdala galanin, whereas unpunished respondin g, drinking motivation, locomotor activity, and shock thresholds were unaff ected. No effects on experimental anxiety were seen in the plus-maze follow ing galanin injection. When injected into parietal cortex, no anxiety promo ting properties of galanin were detected. These data suggest that activatio n of galanin receptors in amygdala modulates neurotransmission involved in fear and experimental anxiety. (C) 1999 American College of Neuropsychophar macology. Published by Elsevier Science Inc.