Effects of electrical stimulation on the biochemical changes in the thalamus of AQP4 knockout rats. (A-E) Compared with the CG, external electrical stimulation also equally increased excitatory neurotransmitters amounts, such as glutamate, glutamine, aspartate, and N-acetylaspartate in the AQP4 knockout rats. (H) The results from the MSI images showed that the average density of metabolites significantly increased after electrical stimulation compared with the average density of metabolites in the CG (scale bar, 5 mm). Data are expressed as the mean ± standard deviation. * P < 0.05, ** P < 0.01, *** P < 0.001. Abbreviations: CG: control group; SG: stimulation group; AQP4-: AQP4-deficient group; SG-AQP4-: stimulation and AQP4 deficiency group; PL: process length; PMD: process mean diameter; MSI: mass spectrometry imaging.