[Effect of dalargin on the processes of memory and learning in the rat]

In experiments on rats, the influence was studied of dalargin on the elaboration and preservation of various homogeneous and heterogeneous conditioned reflexes (CRs) elaborated in single and multiple pairings. The effect of dalargin on the processes of learning and memory was compared with the action of the peptide on the activity of hypothalamic neurones. Administration of dalargin delayed the elaboration of maze defensive CRs and practically did not affect the elaboration of two-way avoidance. The preservation of CR also deteriorated under the influence of dalargin. Administration of dalargin 10 min before the CRs testing did not prevent their reproduction. When using CRs elaborated in a single pairing, dalargin disturbed the preservation of the drinking CR and improved that of passive avoidance CR. Dalargin in this dose affected the emotional state of animals in the open field and did not significantly affect their motor activity. Dalargin suppressed impulse activity in 17 out of 22 tested neurones of the lateral hypothalamus, with maximum effect in 20-50 min after its administration. The obtained data show that the character of dalargin action on the elaboration of CR and mainly on its consolidation, depends on the character of the elaborated CR and is probably due to great extent to the effect of the peptide on the brain emotional mechanisms.