Figure 1

From: Functional Status of the Serotonin 5-HT2C Receptor (5-HT2CR) Drives Interlocked Phenotypes that Precipitate Relapse-Like Behaviors in Cocaine Dependence

Figure 1

Impulsive action phenotypes are identifiable in an outbred rat population. Rats were required to meet an acquisition criteria of a minimum of 50 correct responses, >80% accuracy and <20% omissions on the final one-choice serial reaction time (1-CSRT) task training stage (0.5 s stimulus duration, 5 s limited hold and 5 s intertrial interval, ITI5) before being tested on an ITI8 challenge session to more easily detect phenotypic differences in inherent impulsive action. (a) The number of premature responses made during the ITI8 challenge session was used to stratify rats as high impulsive (HI) or low impulsive (LI) relative to rats in the interquartile range. (b) HI rats exhibited higher numbers of premature responses vs LI rats on two separate ITI8 challenge sessions conducted when the cohort initially met criteria (ITI8 challenge #1; day 25–30 on average) and then upon retest (ITI8 challenge #2; day 92 of 1-CSRT task maintenance), respectively (*p<0.001 vs LI). (c) The impulsive phenotype was identifiable and stable throughout >75 days of 1-CSRT sessions (ITI5) (HI vs LI at day 35 (*p<0.05 vs LI), day 50 (*p<0.05 vs LI) and day 75 (*p<0.05 vs LI)).