Effects of the selective alpha 1-adrenoceptor blocker prazosin on EEG sleep and waking stages in the rat.
In order to gain a better understanding of the role of the noradrenergic system in the control of the EEG sleep-waking stages, the effects of the selective alpha 1-antagonist prazosin was investigated in the rat. Oral doses of prazosin (0.1-10 mg/kg) were administered that have been shown to enter the brain. EEG sleep and waking stages were recorded either during 8 h after drug administration at 8.00 in the morning or during 48 h after drug administration at 16.00 in the afternoon. It was found that prazosin at doses of 0.1-10 mg/kg shortened quiet waking. Starting at 1 mg/kg paradoxical sleep (PS) was shortened and, most interestingly, active waking and slow wave sleep (SWS) were prolonged. PS spindles and dozing were shortened after a latency of some hours during the 48-hour experiment. However, during the 8-hour experiment PS spindles were prolonged at 0.32 and 1 mg/kg. These data suggest that in the rat alpha 1-adrenoceptor inhibition in the brain allows the occurrence of active waking and SWS and suppresses PS.
Kleinlogel
H
H
EEG Labor, Contract-Research, Bern, Switzerland.
D000818:Animals; D001143:Arousal / Q000187:drug effects; D001921:Brain / Q000187:drug effects*; D004569:Electroencephalography / Q000187:drug effects*; D005260:Female; D011224:Prazosin / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects*; D012894:Sleep Stages / Q000187:drug effects*; D014851:Wakefulness / Q000187:drug effects*
D011942:Receptors, Adrenergic, alpha; D011224:Prazosin