LEPR and Anxiety: Our results showed that downregulation of the endogenous LepR in the VTA enhanced the effect of cocaine with no significant effects on anxiety in the elevated plus maze test, although there was a trend for a reduction in the time spent in the center zone in the open-field test, which was consistent with the recent publication by Liu et al.32 The HPLC analysis detected increased dopamine levels in the NAc after knockdown of the LepR in the VTA (Figure 2d), suggesting LepRs in the VTA are required for the function of dopaminergic axons innervating the NAc.