Early-life experiences modulate exploratory behavior and reward consumption in adolescent C57BL/6 mice.

Early-life experiences during rearing are key modulators of behavioral development. We aimed to examine whether sex and rearing conditions modulate exploratory behaviors and hedonic sucrose consumption in adolescent C57BL/6 mice. A factorial ANOVA 2 (Sex) × 5 (Rearing Condition: single mother [SM], biparental [BP], SM with environmental enrichment [SM-Ea], BP with environmental enrichment [BP-Ea] and communal rearing [CC]) factorial design was used to examine behaviors in the Concentric Square Field (CSF) and sucrose consumption in a preference test. Preliminary analyses indicated that CC adolescents showed greater sucrose consumption than all other groups. In addition, SM-Ea and BP-Ea adolescents showed higher sucrose intake than their respective non-enriched peers. In the CSF, a main effect of Ea was observed: SM-Ea and BP-Ea adolescents displayed higher frequencies of entries into transitions and open-field zones. Regarding sex effects, females showed a higher frequency of entries into the light and bridge zones, and a greater sucrose preference than males. Overall, these preliminary findings suggest that greater social complexity and enriched environment are associated with increased preference for natural rewards and enhanced exploratory behaviors in novels contexts. These distinct behavioral profiles suggest that early-life experiences may differentially shape these behavioral domains. Further analyses are ongoing to confirm and extend these findings.