[Neuropharmacological studies on drug dependence (II). Changes in spontaneous motor activity, EEG and brain monoamines during the period of dependence development and of abrupt withdrawal in rats, with special reference to circadian rhythm (author's transl)].
The present study was an attempt to determine whether the circadian rhythm as recorded by Animex and EEG can be used as an indicator of drug dependence in rats, and also to examine the correlation between drug dependence and changes in several monoamines. Repetitive injections of morphine (MP), methamphetamine (MAPT) and cocaine (CC) markedly increased motor activity for about 4 hours post-injection, depending on the number of injections and also remarkably increased the state of wakefulness (AW), but decreased the amount of both slow wave sleep (SWS) and fast wave sleep (FWS) in the EEG sleep-wakefulness cycles during the 7-hour observation period. The injection of MP induced the dissociation between EEG and behavior. SWS increased in phenobarbital (PNB)- and diazepam (DZP)-dependent rats. Abrupt withdrawal of MP resulted in a consistent decrease in motor activity, an increase in AW, and a decrease in SWS and FWS both during the day and at night. The withdrawal of PNB and DZP produced an increase in motor activity and AW, and a decrease in SWS both during the day and at night. The circadian rhythm seen during the course of repetitive injections of MAPT and CC disappeared immediately following the withdrawal. Normal rhythm was recovered with an increase in SWS at night. Repetitive administration and subsequent abrupt withdrawal of the drugs altered the contents and turnover rates of the three monoamines.
D000818:Animals; D001679:Biogenic Amines / Q000378:metabolism*; D001921:Brain / Q000378:metabolism*; D002940:Circadian Rhythm; D003042:Cocaine; D003975:Diazepam; D004569:Electroencephalography; D006801:Humans; D008297:Male; D008694:Methamphetamine; D009021:Morphine Dependence / Q000503:physiopathology; D009043:Motor Activity; D009293:Opioid-Related Disorders / Q000503:physiopathology; D010634:Phenobarbital; D051381:Rats; D013375:Substance Withdrawal Syndrome / Q000378:metabolism / Q000503:physiopathology*; D019966:Substance-Related Disorders / Q000378:metabolism / Q000503:physiopathology*
D001679:Biogenic Amines; D008694:Methamphetamine; D003042:Cocaine; D003975:Diazepam; D010634:Phenobarbital