[Effect of constant darkness on relearning in a Y maze and on the temporal dynamics of forced swimming in rats of different ages].

Prolonged keeping of rats in darkness significantly activated them. This effect manifested itself in shortening of conditioned avoidance latency in the Y-maze against the background of relearning improvement in young (8-9 weeks) animals and its deterioration in mature (18-20 weeks) ones. In animals of various age groups the share of active swimming and the number of active attempts to leave the vessel increased with a decrease of the duration of immobilization in the structure of forced swimming. A significant increase of the number of immobilization short cycles (up to 6 s) on the actogram and a reduction in the number of more protracted immobility periods were noticed. Participation is suggested in such effect realization of biologically active pineal gland factors.