OBJECTIVE: Medical emergency units have increasingly to deal with seizures associated with cocaine abuse, which are seen as a determinant of cocaine-related lethality in humans. Cocaine is an excitatory drug that inhibits catecholamine reuptake and induces sleep deprivation. In view of the fact that stress plays an important role in modulating drug action, the aim of this study was to compare whether paradoxical sleep deprivation and other modalities of chronic stress influence the proportion of cocaine-induced seizures in male rats.
METHODS: The incidence of seizures was measured for 60 minutes after acute administration of cocaine to rats (40, 45, 50 and 70 mg/kg) that have been submitted to different modalities of stress (paradoxical sleep deprivation, footshock, swimming and immobilization), applied repeatedly for 4 days, and then compared with non-stressed rats.
RESULTS:Cocaine induced seizures in 10% of control rats, and among stressful events this effect was potentiated only by paradoxical sleep deprivation, since 90% of the rats had seizures.
CONCLUSION: Our data show that selective sleep loss triggers a marked increase in the number of cocaine-induced seizures, suggesting that the absence of sleep per se has a relevant effect in modulating such events.
Keywords: Sleep deprivation; Cocaine/adverse effects; Seizures; Stress, psychological; Dopamine; Disease models, animal; Rats