Evaluation of the behavioral differences between SHR and Wistar rats in a FI 2min-EXT 5min schedule of reinforcement

Abstract

Attention Deficit Hyperactivity Disorder is charaterized by inattention, hyperactivity, impulsiveness and has incidence as higher as 12% on childhood. This disorder is associated to other disorders like, for example, substance abuse. Validation of animal models becomes essential to clarify the role of behavioral and neurobiological variables in laboratory. The animal model that is most often used is the rats from SHR strain, because they present characteristics that are similar to the disorder on its etiology, symptomatology and treatment. The main procedure used for the evaluation of these properties has been the multiple schedule FI 2min - EXT 5min. This schedule is used to evaluate different behaviors in the presence of different stimulus: the FI component measures reactivity to reinforcers, activity and motor impulsiveness, while the extinction component measures sensitivity to stimulus change and sustained attention. In particular, on this multiple schedule, a response-feedback light is frequently used. It seems to work as conditioned reinforcer for the SHR strain. The present project's goal is to replicate and adapt the procedure of multiple schedule FI 2min - EXT 5min, and evaluate the differences between rats from SHR and Wistar strains. Therefore, this experiment intend to investigate while the differences between the two strains occur without the response-feedback light.