[Functional significance of the accessory optic system in the development of the "wakefulness-sleep" cycle].

The new data on the role of accessory optic system in producing of some behavioral forms are presented. It was obtained in hens with bilateral destruction of nucleus ectomammilaris that the duration of active awake stage is considerably decreased, the passive defence reaction and the alert reaction are much weaker. The sleep stage is much longer and the percent of paradoxal sleeping accompanied with active eyes movements is increased. In the hens operated 5,2 percent from 6 percent of paradoxal sleep stage is accompanied with the active eyes movements, but in the intact animals it is only 0,5 percent from 5 percent. It has been shown experimentally that the accessory optic system influenced the flexor mussle tonus.