The present report demonstrates that post-weaning social isolation alters principal components of the endocannabinoid system in limbic brain regions. The observed dysregulation of the endocannabinoid system may, therefore, contribute to the abnormal behavior of isolates. Chronic experimenter handling both reduces and treats the perturbed behavior of isolates in emotionality-and attentional sensitive assays. Handling also specifically modulates the endocannabinoid system. However, chronic handling alone is not sufficient to reverse the abundance of social deprivation-induced changes in cannabinoid receptor densities or endocannabinoid levels. These observations support a pivotal role for the endocannabinoid signaling system in the adaptation to stressful life events (for review see Finn, 2009, Rossi et al., 2009) as well as in emotionality-related disturbances (Leweke and Koethe, 2008, Lutz, 2009).
