Figure 1. Schematic representation of the effects of a HFD and obesity on inflammation, neurogenesis, and gliosis in the hypothalamus.

As indicated by the work of McNay et al. (12), DIO is associated with a progressive reduction in neuronal turnover in the hypothalamus. In contrast, the work of Thaler et al. (13) demonstrated that hypothalamic inflammation and gliosis displayed a biphasic pattern, with peak inflammation preceding the development of obesity (13). Plus signs indicate the degree of effect in each case.