[Differences in the anxiety level of 2 rat strains can be determined by the density of benzodiazepine receptors in the brain].

The object of the present work was detection of the genetic differences in the anxiety level evaluated in a number of behavioral tests and according to the characteristics of benzodiazepine receptors binding in the brain of rats of two inbred strains, WAG/G and Fischer-344. In all experimental situations ("conflict open field test", "mink chamber", "light-dark chamber", "Vogel's test", "elevated plus maze") Fischer-344 rats demonstrated a higher anxiety level than that of WAG/G rats. The concentration of benzodiazepine receptors in the brain was much higher in WAG/G than in Fischer-344 rats. Benzodiazepine receptor affinity had no strain differences. The results of our experiments show the important role of the primary genetic characteristics of the animals in the formation of their response to stress. Apparently, rats with an initially more active endogenic benzodiazepine system of the brain respond less emotionally to stress stimuli and demonstrate a lower anxiety level receptors.