Date of Completion

2022

Document Type

Honors College Thesis

Department

Psychology

Thesis Type

Honors College, College of Arts and Science Honors

First Advisor

John Green

Keywords

cognitive flexibility, the prefrontal cortex, the infralimbic cortex, operant learning, pharmacological inactivation, set shifting

Abstract

The prefrontal cortex contributes to a wide variety of executive functions (working memory, inhibitory control, cognitive flexibility) in humans. Rodent studies provide further insight into how the prefrontal cortex may support cognitive abilities. A region of the rodent medial prefrontal cortex, the infralimbic cortex, may be important in cognitive flexibility, suppressing previous learning so that new learning can be expressed. In the current experiment, we hope to identify the role of the infralimbic cortex in adult male rats in a set-shifting task by directly comparing rats with pharmacological inactivation of the IL to vehicle (control) rats in a T maze task. Rats first learn to locate a food reward based on either the color or texture of the arms (Set 1). The next day, they learn to locate the food reward based on the opposite stimulus dimension (Set 2). We hypothesize that the infralimbic cortex affects learning and performance in a set-shifting task and predict that control rats will perform better (reach criterion with 8 correct arm choices in a row) in Set 2 more quickly (in fewer trials) than infralimbic cortex-inactivation rats. We did not find support for our hypothesis; pharmacologically inactivating the infralimbic cortex with GABA receptor agonists (baclofen/muscimol) had no detectable effect on cognitive flexibility in adult male rats. We discuss some reasons why we might not have observed pharmacological inactivation effects in the current study, such as the type of pharmacological inactivator used when compared to prior studies and the low number of rats we were able to test.

Comments

The full contents of this thesis are available only in the Honors College office.

Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.

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