comparison of the effects of lesions of the dorsolateral and dorsomedial striatum on appetitive instrumental learning.
Published: 2004
Language: eng
Number of pages: 256
Description: Based on the pattern of findings, it is concluded that the dorsolateral striatum is necessary for stimulus-response learning, while the dorsomedial striatum has little or no involvement in this form learning.This thesis investigates the role of two regions of the dorsal striatum in instrumental learning. Previous research has identified the dorsal striatum as being important for some forms of learning and memory. Functionally, a wide range of evidence has also suggested that the dorsal striatum can be thought of as consisting of two distinct regions, based on a medial-lateral topography. Despite such evidence, very little research has been conducted to investigate how these two areas of the dorsal striatum might differ in regards to their roles in learning and memory.One drawback to these experiments was the inability to rule out the possibility that the deficits seen in animals with lesions of the dorsolateral striatum were due to an impairment in skilled motor responding. Thus, the remaining experiments sought to assess the extent to which the impairments seen in experiments 1 to 3 were due to deficits in skilled motor ability.Experiments 1 to 3 investigated the effects of excitotoxic lesions (quinolinic acid) of either the dorsolateral or dorsomedial striatum on the acquisition of a variety of learning tasks, designed to differ in the extent to which they required the use of stimulus-response learning. Experiment 1 utilized a conditional discrimination task, thought to require the development of stimulus-response associations. Experiment 2 utilized a conditioned place preference task, thought to require the development of stimulus-outcome, and not stimulus-response, learning. Experiment 3 utilized a mixed discrimination task, which is likely to involve both stimulus-response and stimulus-outcome learning. Animals with lesions of the dorsolateral striatum showed a pattern of impairment which consistent with the notion that this area of the brain is involved in stimulus-response learning. In contrast, animals with lesions of the dorsomedial striatum showed little impairment on any of these tasks.
Notes: Adviser:  Robert McDonald.

Thesis (Ph.D.)--University of Toronto, 2004.

Electronic version licensed for access by U. of T. users.

Source: Dissertation Abstracts International, Volume: 65-10, Section: B, page: 5454.