Voluntary alcohol binge-drinking in adolescent C57Bl6 mice induces delayed appearance of behavioural defects in both males and females

Adolescence is a developmental period characterized by significant changes in brain
architecture and behaviour. The immaturity of the adolescent brain is associated with
heightened vulnerability to exogenous agents, including alcohol. Alcohol is the most
consumed drug among teenagers, and binge-drinking during adolescence is a major
public health concern. Studies have suggested that adolescent alcohol exposure may
interfere with the maturation of frontal brain regions and lead to long-lasting behavioural
consequences. In this study, by using a slightly modified version of the Drinking
in the Dark paradigm, adolescent C57Bl6 mice reach high blood alcohol concentration
after voluntary binge-drinking. In order to assess short- and long-term consequences
of adolescent alcohol exposure (AAE), a battery of behavioural tests was
performed during late adolescence and during adulthood. We showed that AAE had
no short-term effect on young mice behaviour but rather increased anxiety- and
depressive-like behaviours, as well as alcohol consumption during adulthood. Moreover,
alcohol binge-drinking during adolescence dramatically decreased recognition
memory performances and behavioural flexibility in both adult males and females.
Furthermore, we showed that voluntary consumption of alcohol during adolescence
did not trigger any major activation of the innate immune system in the prefrontal
cortex. Together, our data suggest that voluntary alcohol binge-drinking in adolescent
mice induces a delayed appearance of behavioural impairments in adulthood.