Co-distribution of the cannabinoid CB1 receptor and the 5-HT transporter in the rat amygdale

Cannabis sometimes causes dysphoria rather than euphoria; however, evidence relating to the interaction between the cannabinoid and 5-hydroxtryptamine (5-HT) systems is limited, especially in areas of the brain such as the amygdale. Here we report that cannabinoid CB1 receptors and 5-HT transporter proteins are co-distributed in the amygdale, suggesting the possibility that activation of cannabinoid CB, receptors might cause a reduction in 5-HT release, similar to its effect on other neurotransmitters, thereby resulting in dysphoria. (c) 2006 Elsevier B.V. All rights reserved.