MONOAMINERGIC AMYGDALAR CONTROL OF REINFO RCING ACTION OF CONDITIONED-STIMULI

Microinfusions of 5-HT and NA (30-50 mcg; 5 mcl) into the amygdalar nu clei (the central nucleus) were found to induce, correspondingly, inhi bition and enhancement of acquired forms of behaviour conditioned by r einforcing, goal-directed action of phasic and instrumental-situationa l stimuli. After DA microinfusions in doses of 30-60 mcg various alter ations of conditioned activity were observed in different animals rese mbling the results of 5-HT or NA action. Inhibitory action of 5-HT and excitatory action of NA in the amygdala are supposed to provide a str uctural work of stimuli reinforcing value perception and transswitchin g of the behaviour to the stimuli. It is assumed that such mental depa rtures in humans as emotional dullness and increased automatism may be developed during an increased endogenous 5-HT release in the amygdala . On the contrary, delay at the intermediate goals and application of the main motive to subsidiary operations may be underlied by NA releas e.