[The effect of arecoline on the structure of sleep and wakefulness in hens].

In chronic experiments on hens, studies have been made on the role of cholinergic mechanisms in regulation of the cycles "awakefulness-sleep". A cholinomimetic, arecoline, was used which stimulates M-cholinoreceptive brain neurons. Arecoline was injected intramuscularly in a dose 0.2 mg/kg of body weight. It was shown that cholinergic mechanisms are involved into the formation of "awakefulness-sleep" cycles in hens. Activation of these mechanisms facilitates paradoxical stage of sleep and expecially such its components as rapid eye movements, the decrease of tonus in neck muscles and, presumably, ponto-geniculo-occipital discharge. Arecolin affects not only the structure of paradoxical sleep, but both the awakefulness and mechanisms of slow-wave sleep stage.