Variation of the choline signal intensity in the dorsolateral prefrontal cortex of rats exposed to the forced swimming test as detected by in vivo 1H MR spectroscopy

Background: H-1 magnetic resonance spectroscopy (MRS) has documented an increased Cho/Cr ratio in the dorsolateral prefrontal cortex (DLPFC) C in major depressive disorder (MDD). The aim of this study was to investigate neurochemical alterations in the left DLPFC, considered a main area of pathogenesis in depression, using rats exposed to the forced swimming test (FST). Materials and methods: Twenty-four male rats were used for the MRI and in vivo 1 H MRS studies. Rats exposed to the FST to induce a depressed mental status. Using in vivo H-1 MRS, the metabolite ratios of the rats with a depressed mental status and the controls, were measured and the values of the two groups were compared. Results: The Cho/Cr and Cho/NAA ratios in the DLPFC of the rats with a depressed mental status were significantly higher than that in the controls. Conclusions: The present study demonstrates a significantly increased Cho/Cr ratio in the DLPFC of rats with depression compared with controls. This result may suggest an accelerated turnover of membrane without neuronal loss is occurring in the DLPFC of the rats with depression. (c) 2007 Elsevier B.V. All rights reserved.