Cerebral metabolic changes in a depression-like rat model of chronic forced swimming studied by ex vivo high resolution 1H magnetic resonance spectroscopy

Many previous in vivo (1)H magnetic resonance spectroscopy (MRS) studies have shown that patients with major depressive disorder (MDD) are associated with perturbations of cerebral metabolism of neurotransmitters glutamate (Glu) and gamma-aminobutyric acid (GABA). In this study, we investigated the changes of cerebral metabolism in a depression-like rat model of chronic forced swimming stress (CFSS). The aims are to further understand the pathophysiological mechanisms underlying CFSS treatment, and to further establish the face and predictive validity of the CFSS model. The results showed that, relative to control, the CFSS rats had significantly reduced Glu, taurine and glutamate + glutamine (Glx) levels in the PFC, and significantly reduced N-acetyl aspartate (NAA) level, Glu level and Glu/GABA ratio in the hippocampus. Taking together, these results suggest that CFSS treatment can induce region-specific changes in the metabolism of Glu. The CFSS model might be used to study antidepressants specifically targeting the central glutamatergic system.