125 | Characterization of impulsivity differences between adolescent and adult rats in a self-initiated rewarded task

Cognition, Behavior, and Memory

Author: Micaela Betsabe Marini | Email: micaelamarini@gmail.com

Micaela Betsabe Marini 1°2°, Maria Cecilia Martinez 1°2°

1° Laboratorio Bases Neuronales del Comportamiento, Grupo Neurociencia de Sistemas, IFIBIO-Houssay, Facultad de Medicina, UBA-CONICET
2° Departamento de Fisiología, Biología molecular y celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires

Mammals undergo multiple physiological and behavioral changes associated with the transition between youth and adulthood which help them acquire the skills necessary for their independence. In general, adolescents exhibit characteristic behaviors, such as increases in social interactions, a preference for novelty, and risk-taking activities.
In previous work from our lab, we found age-related differences in the performance of male Long Evans rats in a self-paced rewarded task. Since developmental divergences between sexes might affect learning, here we studied the performance of both male and female adolescents and adults. In this task, after a minimum waiting interval of 2.5 s, the animals must enter a nose poke and emit an eight-lick sequence onto a sipper tube to obtain a reward.
Consistently with our former electrophysiology results, we found a higher prevalence of impulsive trial-starting in adolescents. We also analyzed other behavioral markers that could account for the premature response in adolescents such as locomotor activity, memory formation, and decision-making in the spontaneous exploration of a multiple-regions arena.
Our results show that adolescent rats display more premature responses in the rewarded task. Still, this impulsivity is not related to increases in their locomotor activity, deficits in memory formation, or risk-taking behaviors, suggesting impulsivity of action could be an individual trait.