[The participation of the neostriatal cholinergic system in the differentiation of acoustic signals in dogs].

In chronic experiments on six dogs the influence was studied of micro-injections of choline agonist carbocholine (0.05-0.2 mkg) and of blocker of choline receptors atropine (40 mkg) in the caudate nucleus head of the left and right hemispheres on realization of instrumental defensive reflexes, connected with the maintenance of definite posture and on differentiation of signals in defensive situation. It has been shown that the cholinergic system of the neostriatum participated in realization of both the motor and sensory mechanisms in connection with the realization of motor responses to defensive and differentiation signals. Analysis of the obtained results also allowed to make a conclusion that the influence of carbocholine micro-injections into the neostriatum on differentiation depended on a number of factors: it did not take place when the signal was poorly distinguished (judging by the values of motor components to defensive and differentiation signals) or, on the other hand, against the background of stable differentiation reaction in other animals, i.e. in case of complete learning.