Posted 01 December 2003 - 01:30 AM
Here are some notes I have on piracetam and sleep. Most are probably direct quotes from the literature. Piracetam appears to increase REM sleep reliably and slightly decrease total sleep time.
The impact of prolonged injection of piracetam (2 months), meclophenoxate (5 months), and mexidole (5 months) on the bioelectrical activity of the sensomotor cortex and dorsal hippocamp was studied in rats who behaved freely. The injects increased and stabilized the predominant peak of EEC spectra power by the Fourier method. Discontinuation (24 hours) of piracetam failed to impair EEG spectra and bioelectrical activity. Increasing the basic effects of nootropic drugs given chronically versus acutely suggests that chronic injection enhanced their action. The drugs under study elevated the level of wakefulness and excitability of the animals, which is likely to underlie the neurophysiological mechanisms responsible for behaviour optimization under the influence of these agents. [59]
The effects of repeated application of nootropic drugs on the sleep-wake cycle were investigated in rats. Piracetam, meclofenoxate and pyritinol were injected intraperitoneally, 100 mg/kg per day, during a period of 10 days. The sleep-wake cycle was recorded each day between 8 a.m. and 4 p.m. Repeated administration of piracetam and meclofenoxate led to an increase of the paradoxical sleep, a decrease of waking, and a very small increase of slow-wave sleep. Pyritinol, on the other hand, decreased the amount of paradoxical sleep. The paradoxical sleep latency was reduced by piracetam and meclofenoxate and enhanced by pyritinol, respectively. These findings and also previous results show that nootropic drugs have different effects on sleep, especially on paradoxical sleep. The possible relationship between sleep effects and memory effects of nootropic drugs and the usefulness of sleep studies for screening of nootropics are discussed. [72]
Pharmacological analysis was used for studying the influence of 24-hour deprivation of paradoxical sleep by Jouvet method on retention of conditioned reaction of passive avoidance in rats. Psychotropic substances of different action were used for the analysis: nootropes as anti-amnestic--pyracetam (400 mg/kg), kleregil (100 mg/kg), centrofenoxin (50 mg/kg) and watersoluble salt of 3-oxypiridin derivative (3-OP) (50 mg/kg) and tranquilizer of bensodiazepine series phenazepam (1 mg/kg) as antistress and antiphobic. It was established that 24-hour deprivation disturbed the elaborated reaction but did not change the rate of emotionality and orienting-investigating behaviour of rats in the open field. Nootropes effectively restored the conditioned passive avoidance reaction while phenazepam had no effect. This allows to suggest that Jouvet method of paradoxical sleep deprivation elicits amnesia and its cause is not only stress but deficit of paradoxical sleep. [81]
The effect of nootropic drugs on sleep-walking pattern was investigated in adult male Wistar rats. Continuous polygraphic sleep recording was made 8 h per day between 8.00 a.m. and 4.00 p.m. Piracetam (100 mg/kg), meclofenoxate (100 mg/kg), pyritinol (100 mg/kg), or methylglucamine orotate (225 mg/kg) were injected intraperitoneally immediately before the onset of recording. The substance effects were compared to pre-drug and post-drug NaC1 control days. The paradoxical sleep (PS) latency was prolonged by pyritinol and methylglucamine orotate. The percentage of PS was decreased by pyritinol and methylglucamine orotate, but increased by piracetam. Pyritinol and methylglucamine orotate decreased the number of PS episodes, whereas piracetam increased the mean duration of PS episodes. Meclofenoxate had no significant effects except for an increase in the number of very long PS episodes (5 min or more). Slow wave sleep and walking were affected only in the case of pyritinol. But also pyritinol, similar to piracetam and methylglucamine orotate, seems to have selective actions on PS as shown by the PS/total sleep ratio. [87]
The effect of Vincamine and Piracetam, two geriatric drugs, on sleep behavior of the laboratory cat was studied. The animals were chronically prepared for recording of the EEG of the cerebral cortex, the lateral geniculate body, and the hippocampus, and for recording of eye movements, the muscular tonus and respiration. During the experiment, sleep and waking behavior were monitored by the above mentioned telemetrically transmitted indicators and also through observation via closed-circuit television. Both Vincamine and Piracetam in doses of 1 and 300 mg/kg p.o., respectively, enhance absolute and relative amounts of paradoxical sleep (PS). Smaller doses have a lesser or no effect on PS. Larger doses again have little effect or else, in the first few hours after application, reduce PS and total amount of sleep. Both drugs have little effect on slow wave and total sleep. Piracetam, but not Vincamine, reduces the prominent frequency of the theta band in hippocampus during PS. The PS-enhancing effect of the two geriatric drugs may be related to their memory-improving influence. [101]
