Effects of environmental enrichment upon anxiety response and ethanol consumpion, after prenatal alcohol exposure

Marrakech

Congreso; 7th Mediterranean Neuroscience Society Conference; 2019

Previous experiments showed that moderate prenatal exposure to ethanol (PE) induces, in rats, alterations in anxiety response and gene expression of the kappa opioid system. These effects may underlie the facilitatory effect of PE on ethanol intake at adolescence. This study assessed if rearing the litters (both dam and offspring) under environmental enrichment may inhibit the effects of PE.Pregnant Wistar rats received daily intragastric administration of ethanol 2.0 g/kg (PE) or vehicle (PV) in gestational days 17 to 20. From birth and until adolescence, the litters were housed in cages equipped with novel objects (environmental enrichment, EE), or in standard cages (non-enriched, NE). The offspring were tested at infancy or adolescence for anxiety response and locomotor activity in a Light-Dark Box (LDB) test, for shelter-seeking and risk-taking behaviors in the concentric square field (CSF) test, and for subsequent voluntary ethanol consumption, in an intermittent 18-hours, 3 weeks intake protocol.PE, male adolescent, rats consumed significantly higher ethanol and showed higher ethanol preference in the last testing sessions than control peers. Moreover, EE rats consumed less ethanol than NE rats, an effect that was noticeable in PV but not in PE subjects. The PE offspring exhibited, when compared with PV peers, lower latency of exit the white area of the LDB and alterations in overall locomotor activity. EE subjects also spent more time in the open area of the CSF. These results indicated that EE can reduce anxiety responses and ethanol consumption during adolescence. PE seems to render the rats less sensitive to some of these beneficial effects of EE.