Evaluating reinforcement-related processes in SHR rats

• Grant number: 19/07418-7
• Support Opportunities: Regular Research Grants
• Start date: August 01, 2019
• End date: July 31, 2022
• Field of knowledge: Humanities - Psychology - Experimental Psychology
• Principal Investigator: Fábio Leyser Gonçalves
• Grantee: Fábio Leyser Gonçalves
• Host Institution: Faculdade de Ciências (FC). Universidade Estadual Paulista (UNESP). Campus de Bauru. Bauru , SP, Brazil

Abstract

Attention deficit hyperactivity disorder (ADHD)is a neurodevelopmental condition characterized by hyperactivity, impulsive behavior and sustained attention deficit. Recent etiological theories implicate changes on reinforcement sensitivity as a core process in ADHD. Spontaneously Hyperactive Rat is a lineage widely used as an animal model of ADHD. Research with SHR had find changes on reinforcement processes as changes on acquisition rate, on conditioned reinforcement function and resistance to extinction. Previous research, conducted in our laboratory, indicated differences on conditioned reinforcement, only after several sessions under extinction contingency. One of the problems on the interpretation of this result is that evaluation of conditioned reinforcement effectiveness was done under an acquisition procedure, that could be, also, affected. Another important finding was that SHR didn't return to baseline performance after several extinction sessions. As there are no previous studies with prolonged exposure to extinction, a study should evaluate if this is specific to conditioned reinforcement or is found under primary reinforcement, too. To evaluate this problems, two experiments are proposed comparing SHR, Wistar Kyoto and Wistar rats. In the first experiment subjects will be submitted to an acquisition procedure for 30 sessions, in which lever presses will be followed by a food pellet. The acquisition process will be compared across lineages. On the second experiment, rats will be submitted to a variable interval baseline under pellet reinforcement. After presenting a stable state performance, subjects will be submitted to 10 sessions under extinction. Data will be compared across lineages through Analysis of variance or similar non-parametric test. (AU)