Astroglial CB(1) Reveal Sex-Specific Synaptic Effects of Amphetamine.

The Nucleus Accumbens (NAc) is a critical brain region for the effects of psychostimulant drugs. Type-1 cannabinoid receptors (CB(1)), the main elements of the endocannabinoid system (ECS) in the brain, participate in these effects and modulate synaptic functions in the NAc. Besides their neuronal expression, CB(1) receptors are also present in astrocytes, where they contribute to the regulation of synaptic plasticity and behavior. However, the impact of astroglial CB(1) receptors on synaptic plasticity in the NAc and on psychostimulant-induced synaptic and behavioral effects is currently unknown. This study shows that the psychostimulant amphetamine impairs a form of astroglial CB(1) receptor-dependent synaptic plasticity in the NAc of male, but not female mice. Consistently, locomotor effects of amphetamine require astroglial CB(1) receptors in male, but not female mice. These results, by revealing unforeseen mechanisms underlying sex-dependent effects of amphetamine, pave the way to a better understanding of the diverse impact of psychostimulants in women and men.