High-runner mice have reduced incentive salience for a sweet-taste reward when housed with wheel access.

摘要: To explore reward substitution in the context of voluntary exercise, female mice from four replicate high-runner (HR) lines (bred for wheel running) and non-selected control (C) were given simultaneous access to wheels palatable solutions as competing rewards (two doses saccharin [0.1, 0.2% w/v]; two common artificial sweetener blends containing [Sweet 'N Low®: 0.1, w/v], aspartame [Equal®: 0.04, 0.08% or sucralose [Splenda®: 0.08, 0.16% sucrose [3.5, 10.5% w/v]). Wheel running fluid consumption measured daily, with each dose (including plain water) lasting days "washout" between solutions. In a separate set mice, experiment was repeated without access. The sweeteners had no statistical effect on running. However, based proportional responses, both significantly elevated C but not HR mice. contrast, high suppressed home-cage activity linetypes. Both generally increased dose-dependent manner. When they wheels, smaller increase when compared housed wheels. Overall, these results provide further evidence that system has evolved, specifically suggest have reduced incentive salience some blends, likely attributable stronger evolved lines.