Fig. 3.

Visual representation of the changes in the frontal cortex and the hippocampal metabolites related to the TCA cycle. Decreased concentrations of citric, succinic, fumaric, and malic acids, with concomitant decrease of niacinamide suggest downregulation of the TCA cycle in the frontal cortex of the running mice. Glutamic and alpha-ketoglutaric acids participate in endogenous GABA production, which is reduced in line with the TCA turnover. In the hippocampus, the metabolites did not differ significantly between the groups. The inactive and running groups were compared separately for the frontal cortex (Cortex) and the hippocampi (Hippo) as marked by the dotted line. Median with min. - max. *p < 0.05, **p < 0.01; n = 6–7