Our results are different from those of (Ramchandani et al., 2011) on the A118G mice they generated. They found that there were no differences between G/G and A/A mice in DAMGO-stimulated [35S]GTPγS binding in the dorsal striatum, NAc and VTA. The discrepancy may be due to different mouse models used. The mice used in the present study has A112G substitution in the mouse MOPR sequence, where those in the Ramchandani et al. (2011) study have the first exon of the human MOPR gene with A118 and G118 in A/A and G/G mice, respectively.
