Does Chronic Stress Alter the Influence of Glucocorticoids on Hippocampal-dependent Cognition?
Young, M.B., Wright, R.L., and Conrad, C.D. Department of Psychology, Arizona State University, Tempe, AZ We tested the hypothesis that impairment of spatial learning and memory abilities in rats following a history of chronic stress is mediated by altering the hippocampal sensitivity to the stress hormone corticosterone (CORT), which, at high elevations, impairs those abilities regardless of stress history. A previous study in our lab showed that pharmacological attenuation of CORT elevations with metyrapone, an inhibitor of CORT synthesis, before memory assessment, could return impaired spatial learning and memory abilities in chronically stressed rats to those of non-stressed controls. In this study, we tested whether spatial memory abilities would differ between chronically stressed and non-stressed rats when CORT was dose-dependently replaced immediately after metyrapone administration. Rats were chronically stressed by restraint for 6h/d/21d. We then equalized endogenous CORT lev
