Date of Completion

Spring 5-1-2014

Thesis Advisor(s)

John D. Salamone

Honors Major

Psychology

Disciplines

Alternative and Complementary Medicine | Behavior and Behavior Mechanisms | Chemical and Pharmacologic Phenomena | Experimental Analysis of Behavior | Nervous System Diseases | Neurosciences | Other Chemicals and Drugs

Abstract

Substantial evidence has shown that dopamine (DA), particularly in the nucleus accumbens (NAc), is involved in behavioral activation and effort-related processes, such as overcoming work related response costs. Interference with accumbens DA transmission through administration of the vesicular monoamine transportor-2 (VMAT-2) inhibitor tetrabenazine (TBZ) produces an alteration of response allocation in the concurrent FR5/chow choice procedure, biasing animals toward the lower effort alternative. It has been suggested that these drug-induced shifts in effort-related choice behavior seen in rodents are analogous to symptoms such as psychomotor retardation, anergia, and fatigue, which can be observed in people with depression and other related disorders. Recently, clinical studies have shown antidepressant efficacy of curcumin, a MAO-A/B inhibitor, as an adjunct medication. Curcumin is a naturally occurring compound found in turmeric, a prominent ingredient of curry powder used in ethnic foods. Curcumin has proven successful in traditional rodent models of depression such as the tail suspension or forced swim test. The current study investigated the ability of curcumin to reverse the effects of TBZ on effort-related choice behavior. The effects of TBZ on lever pressing were partially reversed by ingestion of a high dose of curcumin two hours prior to testing. A major problem with curcumin is its poor bioavailability due to fast metabolism; therefore future studies should investigate ways to enhance the absorption of curcumin.