[en] The adolescent period is characterized by behavioral and neurobiological changes, which might predispose adolescents to the long-term negative consequences of alcohol. For example, enhanced risks of alcohol dependence are reported when drinking is initiated early. In the present studies, we used Swiss female mice to test whether chronic ethanol injections during adolescence durably affect the sensitivity to the stimulant effects of ethanol in adulthood. In a first set of experiments, several groups of young (28 day-old) mice were daily injected with various ethanol doses (1.5 – 4 g/kg) to test for ethanol sensitization during adolescence in comparison to adult mice exposed to the same schedule of ethanol injections. The results show that young mice express much higher stimulant effects after acute ethanol injections. However, they also require higher ethanol doses than adult mice to develop a sensitization to the stimulant effects of ethanol. In a second set of experiments, 28 day-old mice were sensitized to ethanol for 14 days with high ethanol doses (2.5 or 4 g/kg) and then tested for the stimulant effects of ethanol and the development of ethanol sensitization in adulthood. The results of this second set of experiments show that mice sensitized to ethanol during their adolescence remain more sensitive to the acute stimulant effects of ethanol in adulthood, especially when high ethanol doses were administered. However, the rate of the development of a sensitization to this effect was only slightly affected relative to adult mice exposed to a chronic ethanol regimen for the first time. Together, these results indicate that adolescent mice are more sensitive to the stimulant effects of ethanol but require higher ethanol doses to develop a sensitization. However, when a sensitization develops during adolescence, these mice still experience higher ethanol stimulant effects when tested in adulthood.
Research center :
Centre de Neurosciences Cognitives et Comportementales - ULiège
