High-fat diet reduces the hippocampal content level of lactate which is correlated with the expression of glial glutamate transporters

Metabolic disorders hamper the brain metabolism and functions. The astrocytic glucose-derived lactate is known to fill the increased energy needs of neurons during synaptic transmission. However, whether systemic metabolism dysregulation affects the astrocytic lactate metabolism in the brain remain unexamined. To address this question, we adopt a 12-week high-fat diet to induce metabolic disorders in adult mice, and the effects of high-fat diet on the lactate metabolism in the hippocampus were examined. Results showed that a 12-week high-fat diet induced obesity and insulin resistance in mice. High-fat diet also decreased the lactate content levels and the expression of glial glutamate transporters, GLAST and GLT-1, in the hippocampus. Strong correlations between the lactate levels and the levels of GLAST and GLT-1 were evidenced. In conclusion, high-fat feeding induces metabolic disorders and disrupts lactate metabolism in the hippocampus. GLAST and GLT-1 may contribute to the HFD-induced abnormalities of the hippocampal lactate metabolism.