Influence of a high-fat diet on brain-derived neurotrophic factor (BDNF)

Abstract

BDNF and its high affinity receptor TrkB play a critical role in the synaptic activity and plasticity of mature neurons and enhance adult neurogenesis. Furthermore, treatment with BDNF was found to attenuate weight gain or even cause weight loss and suppress appetite in rats. The aim of this study was to look at the effect of nutrient intake on BDNF concentrations and cellular proliferation in the brain. Adult male Wistar rats were given one of three diets for 6 weeks: high-carbohydrate, high-fat and high-fat pair fed. Rats were sacrificed at the end of the feeding period and BDNF concentrations in the dorsal vagal complex (DVC), hypothalamus and plasma were measured by ELISA on protein extracts of these samples. The cellular proliferation in the DVC was quantified by Ki-67 immunohistochemistry. Neither BDNF levels nor proliferation were modified by the diet. Secondly, using rats that received the same diets, real time PCR was performed in the DVC, hypothalamus and nodose ganglia in order to compare TrkB receptor levels after fasting or refeeding the animals. Results showed significantly lower TrkB levels in the hypothalamus and nodose ganglia of fasted rats given the high-fat diet compared to the other dietary groups. These two complementary methodological approaches suggest that there might be a relationship between long-term dietary intake and BDNF but further investigations are needed.