Single administration of metyrapone modifies sleep-wake patterns in the rat.
Metyrapone is a glucocorticoid synthesis inhibitor largely used to study glucocorticoid involvement in stress and memory processes. Metyrapone also acts as a stressor and therefore might modify sleep/wake patterns. However, its effects on rat sleep are unknown. We equipped 8 rats for telemetric assessment of EEG and EMG. They received first a saline injection and 2days later a 150mg/kg metyrapone injection. Metyrapone provoked immediately a waking effect together with a 3-h decrease in slow-wave sleep (SWS) and a 5-h decrease in rapid eye movement sleep (REM sleep). Thereafter, the rats exhibited homeostatic compensation through SWS and REM sleep rebounds recovering totally the sleep debt. The finding that metyrapone modified sleep patterns is important to consider for stress and memory studies using metyrapone.
Département des environnements opérationnels, Institut de recherche biomédicale des armées (IRBA/CRSSA), 24 avenue des maquis du Grésivaudan, F-38702 La Tronche-cédex, France. jb.drouet@crssa.net
Jean-Baptiste
JB
Drouet
Colette
C
Rousset
Renaud
R
Maury
Virginie
V
Michel
Alain
A
Buguet
Raymond
R
Cespuglio
Frédéric
F
Canini
D000818:Animals; D000963:Antimetabolites / Q000008:administration & dosage*; D004569:Electroencephalography; D004576:Electromyography; D008797:Metyrapone / Q000008:administration & dosage*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012890:Sleep / Q000187:drug effects*; D012895:Sleep, REM / Q000187:drug effects; D013997:Time Factors; D014851:Wakefulness / Q000187:drug effects
D000963:Antimetabolites; D008797:Metyrapone