Analysis of cytokine levels in the dorsal raphe nucleus (DRN; left panel) and hippocampus (Hippo; right panel) in Control, DR and DIO rats. DRN expression of IL-1α, IL-1β, IL-4, IL-6, TNF-α and IFN-γ were similar in Control rats, DR rats and DIO rats. Conversely, IL-1α, IL-4 and IFN-γ levels were significantly increased in the hippocampus of DIO rats compared to Control rats and DR rats. Data expressed as mean (pg/mg protein) ± SEM. See Table 1 for complete list of DRN cytokines measured; see Table 2 for complete list of hippocampal cytokines measured. [# = p < 0.05 compared to control; % = p = 0.05 compared to DR]