Sleep: changes in threshold to electroconvulsive shock in rats after deprivation of "paradoxical" phase.

Rats were deprived of paradoxical (radid eye movement or REM) sleep for a 6-day period but were allowed substantial non-REM (slow wave) sleep. Thresholds for electroconvulsive shock dropped significantly after deprivation in all these animals, but thresholds in control animals treated in a similar manner, but allowed REM sleep exhibited no change. Deprivation seems to heighten neural excitability.