[Specific neurons for wakefulness in the posterior hypothalamus in the cat].

Using a single unit recording technique in freely moving Cats, we have demonstrated the presence of two groups of neurons in the ventrolateral part of the caudal hypothalamus. One is characterized by a tonic discharge during waking and paradoxical sleep, the other is highly selective to the waking state. This group of neurons showed a slow tonic and regular discharge during wakefulness, a significant decrease in firing rate during stage I slow-wave sleep and a complete cessation of firing during stage II slow-wave sleep and subsequent paradoxical sleep.