Lewis rats have greater response impulsivity than Fischer rats

Lewis rats have greater response impulsivity than Fischer rats.

Impulsivity, a tendency toward immediate action without consideration of future consequences, is associated with a wide array of problematic behaviors. Response impulsivity, a type of behaviorally-assessed impulsivity characterized by behavioral disinhibition, is also associated with health risk behaviors. Response impulsivity is distinct from choice impulsivity, which is characterized by intol...

Nicotine behavioral sensitization in Lewis and Fischer male rats.

Individuals with greater nicotine-reactivity may be more likely to initiate and maintain cigarette-smoking behavior than individuals with less nicotine-reactivity. In rats, behavioral sensitization reflects a progressive increase in the psychomotor response to drugs of abuse thought to result from neuroplasticity in brain regions that mediate their motivational effects. Studying nicotine behavi...

Inflammation-susceptible Lewis rats show less sensitivity than resistant Fischer rats in the formalin inflammatory pain test and with repeated thermal testing.

Comparisons between Lewis and Fischer inbred strains of rats are used frequently to study the effect of inherent differences in function of the hypothalamic-pituitary-adrenal axis on pain-relevant traits, including differential susceptibility to chronic inflammatory disease and differential responsiveness to analgesic drugs. Increasing use of genetic models including transgenic knockout mice an...

Inflammatory Pain Test and With Repeated Thermal Sensitivity Than Resistant Fischer Rats in the Formalin Inflammation-Susceptible Lewis Rats Show Less

Stress Alters the Discriminative Stimulus and Response Rate Effects of Cocaine Differentially in Lewis and Fischer Inbred Rats

Stress enhances the behavioral effects of cocaine, perhaps via hypothalamic-pituitary-adrenal (HPA) axis activity. Yet, compared to Fischer 344 (F344) rats, Lewis rats have hyporesponsive HPA axis function and more readily acquire cocaine self-administration. We hypothesized that stress would differentially affect cocaine behaviors in these strains. The effects of three stressors on the discrim...