Operant testing of thermal preference (0.3°C vs. 45°C). Rats were allowed to roam freely in a two-chambered shuttle box with different floor temperatures on each side. (A) Total time spent on the cold (0.3°C) side. bCCI rats showed marked preference for the warmer side. Total trial duration was for 10 minutes (600 seconds). (p = 0.004 day 4; p < 0.001; F = 804.83; df = 1; two-way ANOVA day 7 to end of trial period). (B) Total crossover events. Rats were started on either 0.3°C or 45°C in a random fashion on the day of testing to prevent acclimatization. Crossover events were measured to either warm or cold side. bCCI rats showed statistically significant fewer crossover events (p < 0.001; F = 109.9; df = 1; two-way ANOVA) than sham operated rats. Data points are group means +/- SEM. (C) Total time spent on the cold (0.3°C) side in a subgroup of 4 rats tested up to 90 days post-surgery showing bCCI rats had a marked preference for the warmer side, which persisted for the total 90 days. Total trial duration was for 10 minutes (600 seconds).