Sensory‑motor performance and neurochemical effects in the cerebral cortex of brain‑derived neurotrophic factor heterozygous mice fed a high‑cholesterol diet

Abstract

Reports suggest that a high‑cholesterol diet may induce neuroinflammation, oxidative stress, and neurodegeneration in brain tissue. Brain‑derived 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 high‑cholesterol diet under normal and reduced BDNF concentrations. C57Bl/6 strain, wild‑type (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 high‑cholesterol diet for 16 weeks. The cylinder test and wire hanging test were performed to evaluate neuromuscular deficits and cortical sensory‑motor 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 high‑cholesterol 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 high‑cholesterol‑fed 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 high‑cholesterol diet.