[Evaluation of exploratory activity and anxiety in rats with different levels of impulsive behavior].

Rats were divided into 3 groups according to their preference for reinforcements of different values. Animals that preferred valuable but delayed reinforcement in more than 70% of cases formed as self-controlled group, less than 30% of cases formed an impulsive group, the rest formed an ambivalent group. Behavior of animals of different groups was scored for exploratory activity and anxiety in x-maze, fear-conditioning and novelty suppressed feeding. The least active and the most anxious in all procedures used were self-controlled rats. Ambivalent animals as compared to self-controlled and impulsive rats were the least anxious in x-maze and had more successful trials in novelty suppressed feeding test. Impulsive animals demonstrated greater percent of freezing response during acquisition of conditioned fear and they were quicker in finding food in novel environment.

[Conservation of the regulatory elements implicated in the control of the rpsB-tsf operon expression in gamma-proteobacteria].

In eubacteria, the rpsB-tsf operon encodes two essential components of translational apparatus, ribosomal protein (r-protein) S2 and elongation factor Ts. Recently, we located the promoter region of the Escherichia coli rpsB-tsf operon and demonstrated that both rpsB and tsf genes are negatively regulated by r-protein S2 at the translational level. In this paper, we present data of phylogenetic analysis showing high conservation of both the promoter signature and the structure of the 5'-untranslated region (5'-UTR) of the rpsB mRNA in gamma-proteobacteria. Despite the difference in length and overall primary structure of the rpsB 5'-UTRs for various representatives of this bacterial phylum, several short regions within the 5'-UTRs appeared to be universally conserved, implying their participation in the expression regulation. Phylogenetic predictions have been experimentally confirmed. We show here that the presumable rpsB promoter regions from Yersinia pestis, Haemophilus influenzae and Pseudomonas aeruginosa are able to drive transcription of the lacZ -reporter in E. coli and that the corresponding rpsB 5'-UTRs are subjected to autogenous repression by r-protein S2 in vivo.