Figure 5.

Ketamine administration rapidly reverses anxiety and anhedonia caused by HFD. (a) Experimental paradigm: rats were exposed to CD or HFD for 140 days, and were then administered ketamine (20 mg/kg) or saline once every 6 days over the last 31 days of behavioral testing. The influence of HFD and ketamine on anxiety was assessed in the (b) novelty suppressed feeding test (NSFT) and (c) its control home cage feeding (HCF), (d) open field test (OFT) and (e) elevated plus maze (EPM). Anhedonia was examined in the (f) sucrose preference test (SPT) and (g) female urine sniffing test (FUST). (h) Novel object recognition (NOR) results. (i) Neither diet nor treatment influenced locomotor activity (LMA). Results are presented as the mean±SEM, n=8 per group. *P<0.05; **P<0.01, ***P<0.001, ANOVA and Fisher's least significant difference post hoc test for multiple-group comparisons.