Date of Completion


Embargo Period



Dr. Heather Read, Dr. Merce Correa

Field of Study



Master of Arts

Open Access

Campus Access


Mesolimbic dopamine (DA), particularly in the nucleus accumbens, is a critical component of the brain circuitry involved in behavioral activation and effort-related processes. Behavioral paradigms have been developed to assess effort-related choice behavior in rodents, including maze procedures and operant tasks. Interference with accumbens DA transmission through DA depletions or injections of low-to-moderate doses of D1 or D2 family DA antagonists produces an alteration of response allocation towards the lower effort alternative. It is suggested that these drug-induced shifts in effort-related choice behavior that are seen in rodents are analogous to symptoms such as psychomotor retardation, anergia, and fatigue, which can be observed in people with depression, parkinsonism, and other disorders. Ecopipam is a highly selective D1 antagonist that has been shown to produce a shift in response allocation in the FR5 choice procedure, decreasing lever pressing and subsequently increasing chow consumption. However, ecopipam has not been evaluated in the T-maze choice procedure. Furthermore, the ability of D1 agonists to reverse the effort-related effects of D1 antagonism or depletions has not been assessed. Therefore, the current studies were undertaken to investigate the effects of ecopipam on effort-based decision making using the T-maze barrier choice task, and to study the ability of D1 agonists to reverse the effort-related effects of ecopipam and the DA depleting agent tetrabenazine.

Major Advisor

Dr. John Salamone