Mirjam I. Schubert1, Simon Beckett2, Clare Spicer2, Charles A. Marsden2, Dorothee P. Auer1
1Division of Academic Radiology, University of Nottingham, Nottingham, UK; 2School of Biomedical Sciences, University of Nottingham, Nottingham, UK
Previously, we found elevated glutamate levels in the hippocampus of adrenalectomized rats treated with dexamethasone, an exogenous glucocorticoid, supporting the hypothesis that corticosteroids induce glutamate mediated excitotoxic processes in the hippocampus. To investigate whether corticosterone, the endogenous glucocorticoid in rodents, would yield similar metabolic changes in the hippocampus, rats were chronically treated with high-dose corticosterone and investigated for metabolic changes by in vivo hippocampal 1H-MRS at 7T. Unexpectedly, there was no change in glutamate but significant reduced glutamine levels in both hippocampi in corticosterone compared to vehicle treated rats suggesting glucocorticoid-induced glial disturbances in the glutamate-glutamine cycle.