Multimodal MRI of Conduction Tracts and Anatomy of the Cerebral Gray Matter in Familial Risk of Affective Disorders and Schizophrenia.

The present study analyzed diffusion characteristics of white matter tracts and grey matter anatomy in 48 mentally healthy participants, including first-degree relatives of patients with schizophrenia (N=13) and affective spectrum disorders (N=13). The subgroup with familial risk of schizophrenia displayed abnormalities in the structural connectivity and increased cortical thickness in the superior frontal gyrus. No differences in the analyzed characteristics were revealed in the subgroup with familial risk for affective disorders. The results are discussed within the framework of the concepts of endophenotypes and processes reflecting compensatory and protective mechanisms.

[Does Impulsivity Affect a Long-term and Working Memory in rats?].

In the present paper usingthe method of delay discounting three groups of animals were discovered: a) those that at choice between immediate weak and delayed strong rewards have chosen an immediate reinforcement (high impulsive rats); b) those that were able to inhibit its own behavior and get the delayed reinforcement (low impulsive rats); and c) the rats with both types of reactions. In the water maze the different groups of rats did find a hidden platform for different time, swum various distance and with different speed. The differences however were significant only at overall comparison (for all days and trials) of the above mentioned parameters of the water maze learning. ANOVAs Group x Days, Group x Trials, and Groups x Days x Trials interactions were insignificant. The data obtained indicate that the difference between groups was appeared evidently due to the difference in general motor activity, rather than difference in their cognitive abilities assessed by reference and working memory tasks.

[Effect of Agonists and Antagonists of α2 Adrenergic Receptors on Choice of Reinforcement Value in Rats with Different Levels of Impulsivity].

The influence of drugs, agonist (clonidine) and antagonist (yohimbine) of α2-adrenergic receptors 5-HT2 on the behavior of rats tested by the method of choice to the value of reinforcement was investigated. Based on the selection of a rat the pedal for immediate poor and delayed valuable reinforcement rats were divided into 3 groups. Rats, in most cases, choosing valuable delayed reinforcements were classified as low-impulsive, those who mainly chosen poor immediate reinforcement to the high-impulsive group. Rats who were not able to determine, was ambivalent group. Administration (i.p.) of the α2-adrenergic receptors agonist clonidine resulted in a reduction of the select valuable delayed reinforcement by low-impulsive animals and increasing the number of missing responses of pressing the pedal in high-impulsive animals. Clonidine also reduced the latency of nose-poking in all groups of animals. The antagonist of these receptors yohimbine did not cause changes in the choice of the reinforcement in all groups of animals. At the same time yohimbine caused a significant reduction in the number of missing responses. The results suggest that the effect of drugs used in this work on α2-adrenergic receptors depends on the individual feature of rats, in particular from high and low degree of impulsivity.