[Reactions of rats to behavior tasks of different degrees of difficulty after flight aboard the biosatellite "cosmos-782"].

Maze behaviour of rats was studied on 6--25th days after exposure on biosatellite "Kosmos-782". Presentation of a foreign stimulus (a bell) on the 6--7th day after return, had a weaker effect on the maze performance in experimental rats, than in the control group. The experimental animals were also better adapted, as compared to the control ones, to an increased functional stress on CNS (increased number of runs in the maze from 3 to 16 in one session), applied on 11--13th day after the return. Similarly, the ability to use previous experience in a new situation, tested an 15--20th day after the return was slightly higher in experimental animals than in the control. During elaboration of a habit in an utterly new complex maze, first runs in each session were performed by experimental rats in the same way as by the control ones, whereas in second runs the afterflight rats did considerably worse than those in the control. The data analysis showed that the described changes in higher nervous activity were not caused by muscle weakness; they were due to exhaustion of the higher parts of CNS, while closing functions remained intact.