Caracterização dos efeitos comportamentais, teciduais e bioquímicos da administração intermitente e episódica de EtOH em ratas da adolescência à fase adulta

Abstract

The consumption of ethanol (EtOH) is enhanced particularly in adolescent female pubic. The EtOH intake and intermittent episodic own consumption rate around 3 times per week. The toxic effects of this kind of consumption is especially dangerous over the continuous consumption of EtOH followed due to the high dietary intakes of abstinence, causing major changes in the central nervous system (CNS) maturing in a short time consumption. Considering the epidemiological relevance and the harmful effects of EtOH on the oxidative balance, hormone production and neurotrophin CNS maturing, the aim of this study was to investigate the behavioural, tissue and biochemical responses derived from intermittent and episodic consumption of EtOH in rats in phase from adolescence to adulthood. Wistar female adolescents (n = 80) received by gavage, distilled water or EtOH (3 g/kg/day) for 3 consecutive days per week. The animals were assessed seven and a half hours after the last administration day 1, 4 and 8 weeks of episodes of binge drinking (37, 58 and 86 DPN, respectively), besides, a period of 14 days of abstinence was added after BD 8 (100 DPN) to evaluate the ability to reverse the CNS damage generated on it. The battery of behavioural tests consisted of spontaneous locomotor activity, object recognition, elevated plus maze, test pole, walking beam and rotarod. The animals were sacrificed and blood samples collected for evaluation of corticosterone levels of malondialdehyde, catalase activity, the activity of superoxide dismutase and glutathione content. Therefore, the hippocampus was dissected to quantify the immunocontent BDNF. The administration of EtOH reached average peak blood concentration of 197.4 mg / dL and the period of 7.5 hours after the last administration EtOH in acute binge blood concentration was 0.7 mg / dL. Thus, the animals underwent behavioural tests post-consumer EtOH, not under the drug effect. Consumption of EtOH in binge did not affect weight gain of adolescent animals into adulthood, however, reduced the exploratory locomotor activity, impaired motor coordination, balance and motor learning associated with bradykinesia, as well as loss in the mnemonic process and increased anxiety-like behaviour. These losses were accompanied by hormonal elevation of corticosterone, reduced hippocampal BDNF levels and systemic imbalance in the oxidative balance. Thus, it was possible to identify that the damage found on the similar behaviour to anxiety, short-term memory, bradykinesia and spontaneous locomotor activity appeared from EtOH post-consumption for three consecutive days, however, they showed no recovery or worsening of damage after repeated episodes. In contrast, there was recovery of short-term memory in object recognition task associated with the return of normal levels of BDNF in adulthood. Moreover, it showed worsening in motor learning in young adult phase followed by gradual and partial recovery after prolonged period of drug withdrawal, yet the loss of motor coordination and balance remained in adulthood.