Cannabinoid receptor subtype 1 (CB1), IL-1Ą and IL-6 are increased in some areas of limbic system after chronic restraint stress

BERENICE BURDET; ANDREA DE LAURENTIIS; ELISA RETTORI; VALERIA RETTORI; MARIA ZORRILLA ZUBILETE

Institute for Advanced Studies, of the Hebrew University of Jerusalem

Workshop; Joint Workshop of the Joint Research Conference of the Institute for Advanced Studies and the Israel Science Foundation on "Cannabinoids in Biology and Medicine"; 2010

Institute for Advanced Studies and the Israel Science Foundation

The aim of this study was to find out if a chronic restraint stress could modify cannabinoid receptors expression as well as IL-1b and IL-6 mRNA in amygdala and hippocampus. Sprague-Dawley adult male rats were divided in 4 groups: control (C) and restraint stress during two hours daily for 7, 14 or 21 days (n=6-8 rats per group). The results showed that there was an increase in corticosterone plasma levels as well as adrenal gland weight in all groups submitted to restraint stress. Oxytocin (OXT) plasma levels were only significantly increased at 7d (p<0.01) and 21d (p<0.05). Hippocampal CB1 mRNA by RT-PCR and protein expression by Western blot showed an increase in all stressed groups. IL-1b and IL-6 mRNA were significantly increased in amygdala only at 14d of stress. Stressed animals showed a reduced habituation in the open field test.   We conclude that in chronic stress cytokines such as IL-1b and IL-6 were increased in amygdala probably due to anxiety and that hippocampal endocannabinoid system participates in this paradigm of stress. (BID PICT 06-0258).