Figure 1.

This artwork provides a schematic of the crossover design employed in the study. 1 week after arrival (habituation period from postnatal day 21–28 (PND21 to PND28), animals were randomly allocated to enriched (environmental enrichment, EE) or standard environment (SE) conditions until adulthood (PND67). At PND67, the animals were exposed to four intermittent, Drinking in the Dark (iDID), cycles. A cycle of iDID is composed of three intermittent drinking episodes, each one consisting of 2 h access to EtOH and 3 h in the dark stage. At PND92, half of the animals switched their environmental conditions and half kept their original housing conditions, which resulted in four experimental groups: EE-EE, SE-SE, EE-SE, and SE-EE. From PND95 to PND120, four new cycles of EtOH iDID were administered. Finally, Elevated Plus Maze (EPM) and Hole Board (HB) tests were performed at the end of the study (EPM on PND135; HB on PND140). EPM and HB procedures were performed in ethanol (EtOH)-free days.