Behavior modification after inactivation of cerebellar dentate nuclei.

Abstract

Effort-based decision making occurs when subjects are given a choice between a reward available at a high response cost and a reward available at a low response cost and is altered in individuals with disorders such as autism or particular patterns of brain injury. The current study explored the relationship between effort-based decision making and reinforcement characteristics in the T maze. This was done using both normal animals and animals with bilateral inactivation of the cerebellar dentate nuclei. Rats chose between alternatives in which one arm contained high-density reinforcement (HR) and the other arm contained low-density reinforcement (LR). During training, the HR arm was obstructed and the point at which the animal no longer worked for reinforcement (breaking point) was determined. The cerebellar dentate nuclei were then transiently inactivated and once again breaking points were assessed. The results indicated that inactivation of the dentate nucleus disrupted effort-based decision making. Additionally, altering both the palatability and the magnitude of the reinforcement were assessed in an attempt to reestablish the original preinactivation breaking point. It was hypothesized that an increase in the strength or magnitude of the reinforcement would promote an increase in the breaking point of the animal even when the cerebellum was inactivated. The results indicated that with both strategies animals effectively reestablished original breaking points. The results of this study will inform the current literature regarding the modification of behavior after brain injury and further the understanding of the behavioral deficits associated with cerebellar dysfunction.

A behavioral and histological comparison of fluid percussion injury and controlled cortical impact injury to the rat sensorimotor cortex

“…[39] Two days of training occurred prior to surgery to establish a pre-injury baseline on the rotarod. Animals were placed on the rotating cylinder against the rotation and the latency to fall was recorded.…”

Is autism a disease of the cerebellum? An integration of clinical and pre-clinical research

“…It is well known, however, that disruption of afferents to the cerebellum results in deficits in the acquisition of classical eyeblink conditioning and causes extinction of eyeblink conditioning in well trained animals (McCormick et al, 1985; McCormick, 2005). Most recently it has been reported that temporary, bilateral inactivation of the cerebellar dentate nuclei reduced operant responding for a food reward (Peterson et al, 2012). These studies are therefore consistent with the idea that the cerebellum potentially may play an important role in human reward processing.…”

Identifying Essential Cell Types and Circuits in Autism Spectrum Disorders

“…However, behaviors outside of the motor domain have been shown to depend on an intact cerebellum, such as those involved in behavioral modification (Peterson et al, 2012). Furthermore, individuals with cerebellar lesions exhibit what has been termed cerebellar cognitive affective syndrome which is characterized by impaired executive functions, disrupted spatial cognition, blunted affect, inappropriate behavior, and language deficits (Schmahmann & Sherman, 1998).…”