FUNCTIONAL-RELATIONSHIPS BETWEEN MOTOR AND SLEEP-WAKEFULNESS CONTROLS

The present paper deals with relationships between neural systems whic h control motor behaviour (pyramidal and extrapyramidal) and sleep-wak efulness states (in particular the reticular formation). We examined s uccessively their anatomical and neurochemical substrates, electrophys iological and functional motor alterations depending on ascending and descending influences from brain stem during the sleep-wakefulness cyc le. These data suggest that sleep-wake states result front the modulat ion of excitability in neuronal pools and that each state results from the co-ordinated working of several functionally different neuronal p ools. Thus, each state could be understood as a sum of behavioural eve nts depending on a neural network. work. We hypothesized that abnormal motor events occurring specifically during a sleep state result from motor structures abnormally recruited in neural networks specifically involved in this sleep state.