Expression of the cAMP response element binding protein (CREB) in hippocampus produces an antidepressant effect

Background: Recent studies that demonstrated that chronic antidepressant treatment increases the expression of the cyclic amp (cAMP) response element binding protein (CREB) in mt hippocampus. The study presented here was conducted to determine if CREB is a relevant target that produces an antidepressant-like effect. Methods: We employed the herpes simple virus (HSC)-mediated gene transfer technique to overexpress CREB and determined its effect on the learned helplessness and forced swim tests, two established models used for pharmacological screening of antidepressant drugs. Results: in the learned helplessness model, rats that received bilateral microinjection of HSV-CREB into the dentate gyrus showed significantly fewer escape failures es in the subsequent conditioned avoidance rest than those injected with control vector (HSV-LacZ). In contrast, microinjection of HSV-CREB in either the CAI pyramidal cell layer of hippocampus or the prefrontal cortex did, Eor produce antidepressant response, In the forced swim test CREB expression in the dentate gyrus resulted in a significantly shorter immobility time than those injected,with HSV-LacZ Conclusions: These results demonstrate that over-expression of CREB in hippocampus results in an antidepressant effect and suggest that CREB may sen e as a potential molecular target for novel therapeutic agents. (C) 2001 Society of Biological Psychiatry.