Analysis of the Relationship between the Concentration of Neurotransmitters and Tau Protein in the Brain of Animals with Chronic Traumatic Encephalopathy

Chronic traumatic encephalopathy (CTE) is a progressive neurodegenerative pathology distinguished by tauopathy and characteristic clinical symptoms potentially mediated by neurotransmitter disturbances. Our aim was to evaluate the relationships between neurotransmitter and tau protein concentrations in the cerebral cortex and hippocampus of rats with CTE. The pathology was modeled in Wistar rats. The levels of dopamine, glutamate, serotonin, GABA, glycine, acetylcholine, and tau protein were assessed in the hippocampus and cerebral cortex. It was found that in rats with CTE, tau protein content increased 27.5-fold (p < 0.05) and 14.1-fold (p < 0.05) in the cerebral cortex and hippocampus, respectively. Increased levels of dopamine and glutamate were also observed, whereas the concentrations of serotonin, GABA, glycine, and acetylcholine decreased in both the hippocampus and cerebral cortex. Regression analysis revealed a very high dependence between tau protein and glutamate concentrations (r2 = 0.9420 for the cerebral cortex and r2 = 0.9664 for the hippocampus).