# Premature release of action sequences in adolescent male rats

## TL;DR

Adolescent male rats show more impulsive behavior in a waiting task compared to females or adults, unrelated to activity or memory.

## Contribution

Identifies sex-dependent impulsivity in adolescent rats as a distinct behavioral trait unrelated to general activity or cognitive performance.

## Key findings

- Adolescent male rats made more premature responses than females or adults in a waiting task.
- Locomotor activity and memory were similar across groups, ruling out general hyperactivity or cognitive deficits.
- Impulsivity in adolescent males reflects a specific behavioral trait linked to risk-taking and psychiatric vulnerability.

## Abstract

Adolescence is a period of transition from childhood to adulthood in which subjects exhibit characteristic behaviors, such as increases in impulsivity, social interactions, novelty-seeking and risk-taking behaviors. Previous studies have shown that adolescents often respond prematurely in operant tasks, but it remains unclear whether this behavior reflects general hyperactivity, cognitive impairments, or if it is a specific form of impulsivity. Here, we trained male and female adolescent and adult Long-Evans rats in a rewarded operant task that required withholding an action sequence for a 2.5 s waiting time. Adolescent males exhibited significantly more premature responses than females or adults, despite achieving similar reward rates. To test whether this behavior was associated with other traits, we assessed locomotor activity in the Open Field and recognition memory in the Y-maze. Locomotor activity and memory performance were comparable between groups, indicating that the increased premature responding observed in adolescent males was not readily explained by differences in general activity levels or cognitive performance. Together, these findings suggest that impulsive responding during adolescence shows a sex-dependent expression and reflects a distinct behavioral component within the context of this task, rather than belonging to broader behavioral differences. Understanding the specificity of adolescent impulsivity may provide insights into vulnerability to risk-taking and psychiatric disorders during adolescence.