Influence of testosterone on some behavioral reactions of male immature rats exposed to continual light

Neurosteroids are a perspective group of effectors that can be used to uncover the mechanisms of neurohumoral control underlying behavioral activity and the biological influence of the photoperiodic stimuli that regulate a number of physiological and metabolic processes of most organisms. At present, the achievements made in this area are the beginnings of elucidation of the complex organization of the circaoscillatory systems and signify progress towards an effective hormonal chronotherapy for the future. The present study shows that infusion of testosterone (40 micrograms/100 b.w.) in male immature white rats subject to continual light leads to an increase in horizontal and vertical locomotor activity in an open field study and to weak prolongation of the latency of thermic pain reaction in the tail flick test. The effect of this steroid was studied at 4 and 24 h after infusion. Testosterone stimulates the exploratory motivation and the emotional state of rats adaptive behavior is modulated by altering exogenic photoperiocity thus increasing the entropy of the behavior. The effects of testosterone differ in that they depend on the biorhythmic activity of the organism. This is in agreement with the belief that there is a connection between steroids and the structural and functional plasticity of the central nervous system.