Sensory­motor performance and neurochemical effects in the cerebral cortex of brain­derived neurotrophic factor heterozygous mice fed a high­cholesterol diet.

Reports suggest that a high­cholesterol diet may induce neuroinflammation, oxidative stress, and neurodegeneration in brain tissue. Brain­derived neurotrophic factor (BDNF) might play a role in protecting against changes induced by high cholesterol. We aimed to assess behavioral correlates and biochemical alterations in the motor and sensory cortices following a high­cholesterol diet under normal and reduced BDNF concentrations. C57Bl/6 strain, wild­type (WT) and BDNF heterozygous (+/­) mice were used to reveal the effects of endogenous BDNF concentrations. We compared diet and genotype effects using four experimental groups: WT and BDNF heterozygous (+/­) groups of mice were each fed a normal or high­cholesterol diet for 16 weeks. The cylinder test and wire hanging test were performed to evaluate neuromuscular deficits and cortical sensory­motor functions, respectively. In addition, neuroinflammation was assessed by tumor necrosis factor alpha and interleukin 6 levels measured in the somatosensory and motor areas. Additionally, MDA levels and SOD and CAT activity were evaluated as oxidative stress parameters. Results showed that a high­cholesterol diet significantly impaired behavioral performance in the BDNF (+/­) group. Diet did not change the levels of neuroinflammatory markers in any of the groups. However, MDA levels, an indicator of lipid peroxidation, were significantly higher in the high­cholesterol­fed BDNF (+/­) mice. The results suggest that BDNF levels might be a critical factor in determining the extent of neuronal damage induced in the neocortex by a high­cholesterol diet.