Effects on a high-fat diet (HFD) on dendritic morphology in the male rat hypothalamic ventromedial nucleus (VMH)

We recently reported that caloric restriction was associated with a selective shortening of dendrites in the VMH. In the present study, we tested the hypothesis that exposure to a high-fat diet, which causes weight gain in a subset of rats, also would be associated with modifications in dendritic morphology. Adult male rats were provided with a 15% fat diet ( n=9) or a 45% fat diet ( n=9) for 17 days. There was substantial variability in the 17-day weight gain in the group of animals given the HFD. Therefore, this group was subdivided. All animals that were within one standard deviation of the average weight gain of the low-fat control group were considered “non-responders” ( n=4). The animals whose weight gain was beyond that range were considered “responders” ( n=5). The HFD-responders consumed more kcal per day and gained more weight than either the control animals or the HFD-non-responders (both p