Chronic restraint stress increases IL-6 and cannabinoid receptor type 1 expression in rat hippocampus

BURDET B; DE LAURENTIIS A; MOHN C; FERNANDEZ SOLARI J; RETTORI V; ZORRILLA ZUBILETE M

Barcelona. España

Congreso; International Congress of Neuroinmunology; 2010

The relation between prolonged stress and the development of psychiatric disorders such as depression and anxiety has been well established (Ader and Cohen, 1993). Given the role of the HPA axis in depression, a recent work (Miller et al., 2009) suggested a critical role for the endocannabinoid system on its regulation.  The aim of the present work was to study the effect of restraint stress on some neuroimmunoendocrine, behavioral and endocannabinoid parameters. Restraint stress was applied to adult Sprague-Dawley rats two hours daily during 7 or 21 consecutive days. The behavioral tests were open field and elevated plus maze. Blood samples were collected and the hippocampi were dissected. Total mRNA and protein levels were analyzed by real time PCR and western blot respectively. The results showed that stressed animals have increased IL-6 and cannabinoid receptor type 1 (CB1) total mRNA and protein levels in hippocampus.  Oxytocin and corticosterone plasma levels were increased as well as adrenal gland weight. Also, the animals showed a reduced habituation in the open field test but no changes in anxiety parameters.  These findings suggest a possible interaction between neuroimmunoendocrine and  endocannabinoid systems in the present stress paradigm. (BID-OCR-AR, PICT-06-0258).