Effects of intra-accumbens adenosine A2A antagonist MSX-3 on locomotor activity (A) and high fat intake (B) prior to administration of saline or DAMGO (0.025 μg/0.25 μl/side) and effects of intra-accumbens saline or the opioid antagonist naltrexone (20 μg/0.25 μl/side) on the high-dose (20 mM) of MSX-3-induced increases of locomotor activity (A) and high fat intake (B). +p<0.05, ++p<0.01, +++p<0.001, compared to 0 mM MSX-3-Saline; *p<0.05, compared to 0 mM MSX-3-DAMGO; ##p<0.05, compared to saline-20 mM MSX.