Alterations within the brain following THC administration are not surprising, given the wide distribution of CB-1 receptors throughout the brain, highly concentrated in areas which have been shown to mediate emotional and affective behavior. Postmortem studies have, in fact, provided evidence for a relationship between CB-1 receptor activity and affective processing. Increases in CB-1 receptor levels have been reported within the prefrontal cortex of suicide victims (Hungund et al., 2004) who met diagnostic criteria for both depression and alcoholism relative to those who met only for alcohol dependence (Vinod et al., 2005), indicating a specific change relative to the affective disorder. In another investigation of CB-1 receptors, Zavitsanou et al. (2004) examined radioligand binding of [3H]SR141716A, an antagonist that specifically targets CB1 receptors of the endogenous cannabinoid system, using quantitative radiographic techniques on postmortem tissue of schizophrenic patients and healthy controls. The authors report a significant increase of CB-1 binding in the schizophrenic brains relative to those of the control subjects, suggesting changes in the endogenous cannabinoid system in the ACC may be involved in the pathology of schizophrenia (Zavitsanou et al., 2004).
