SYN1 and depressive disorder: Similar to previous studies (22, 23, 25), we found that DIO mice exhibited a depressive-like state by showing significantly more immobility time than RD-fed mice, while HFD-fed Syn1-cre; Ghsr f/f mice had a significantly less immobility time than HFD-fed Ghsr f/f mice in the FST (Figure 3B), suggesting that neuronal deletion of GHSR protects against DIO-induced depression.