Effect of activating the putamen on alimentary conditioned reflexes in dogs

The influence was studied of the near-threshold high- and low-frequency stimulation of the putamen on achievement of alimentary conditioned reflexes in dogs. Both low- and high-frequency activation of the examined structure significantly changes the parameters of intermediate secretion, of the salivary conditioned reflexes, without influencing unconditioned ones. Unilateral stimulation disturbs the achievement of positive and inhibitory conditioned reflexes to a greater extent than bilateral one. Difference between the effects of low- and high-frequency stimulation has been revealed.     

Fluorescence of dopaminergic terminals during elaboration of alimentary conditioned reflexes in the cat

A decrease of intensity of fluorescence of dopaminergic terminals in the nigrostriate and mesolimbic systems of rats was revealed under alimentary deprivation and during conditioned alimentary reaction. This decrease detected against the background of catecholamines synthesis blockade (alpha-methyl-para-thyrosine 40 and 80 mg/kg intraperitoneally) testifies to an activation of dopaminergic terminals and participation of nigrostriate and mesolimbic systems in conditioned alimentary reaction.     

Correlations among cortical potentials in the dog during the elaboration of motor alimentary conditioned reflexes

Background electrocortical activity in a frequency band of 1-100 Hz of dogs with electrodes implanted in different neocortical areas was studied before and after elaboration of motor (lever pressing) alimentary conditioned responses. Conditioning led to a significant change of the distribution histograms of cross-correlation coefficients (CC) between the cortical potentials, i. e. the dispersion of CC values decreased and the level of correlation changed as well. In more tranquil animals (with lower CC values before conditioning) the level of correlation significantly increased, in excitable ones (with higher CC values before conditioning) it decreased. CC distributions after the conditioned response elaboration became similar in both cases apparently indicating the formation of a uniform state characteristic for the type of a conditioned response under study.     

The effect of lesions of the dorsomedial thalamic nucleus on alimentary conditioned reflexes and food intake in dogs.

The experiments have been carried out on 6 dogs with type II conditioned alimentary reaction. After achieving the criterion in all animals the dorsomedial thalamic nucleus was destroyed by means of electrocoagulation. After the operation hypophagia developed with a rise in the number of intertrial responses and disinhibition of the alimentary conditioned reaction not exceeding 6 days. The obtained results confirm in part the hypothesis of Brutkowski who regarded this nucleus as belonging to a system controlling feeding behavior.     

Formation of alimentary conditioned reflexes with probable reinforcement in rats with frontal cortex injuries

Alimentary conditioned response to the sound of turning of the feeding-rack reinforced in 33 and 25 per cent of cases was formed faster in rats with frontal cortical lesion than in intact animals. The results obtained permit to suppose that during integrative brain activity the frontal areas of the cerebral cortex participate in organization of behavior with a high probability of reinforcement.