[Neuropharmacologic analysis of the process of developing extinctive inhibition in the lobectomized cat].

Pharmacological action on cholinergic and monoaminergic brain structures in the process of food-procuring reflex extinction was studied in intact and lobectomized cats. Growing stimulation of cholinergic structures of lobectomized animals caused consecutive behavioural changes similar to those appearing during development of active reaction of intact animals to cancellation of the reflex reinforcement. In both cases influences on monoaminergic systems produced analogous effects, but suppressing influence of haloperidol injection on food-procuring activity of lobectomized cats was significantly weakened. Conclusion is made that the development of active reaction of the animal to cancellation of food reinforcement is due to an increasing activation of brain cholinergic structures and consecutive activation of monoaminergic structures. Disturbance of extinction functions in lobectomized cats may be connected with disturbance of monoaminergic systems balance as a result of hyperactivity of dopaminergic structures.