Date of Award


Degree Type


Degree Name

Master of Science


Psychological Science


Psychological Science (MS)

First Advisor/Chairperson

Adam Prus


Neurotensin is a neuropeptide that influences monoaminergic neurotransmission in areas of the brain involved in the pathophysiology of depression. The forced swim test is a commonly used screening model for putative antidepressant medications. Drugs that have antidepressant effects in humans reliably decrease the time animals spend in an immobile posture in the forced swim test without increasing general locomotor activity as measured in an open field test. The present study sought to examine the effects of the neurotensin NTS1 receptor agonist PD149163 and the tricyclic antidepressant drug imipramine on immobility in the forced swim test and on locomotor activity in an open field in mice. PD149163 decreased the total time spent immobile at doses of 0.1 mg/kg and 1.0 mg/kg, without increasing overall locomotor behavior in the open field test. Imipramine produced a reduction in immobility at a dose of 10.0 mg/kg, but not at 1.0 mg/kg, without increasing locomotor activity. These results indicate that since drugs that target the neurotensin system display antidepressant properties in rodent models of depression they may represent a novel mechanism for treatment of depressive symptoms in humans.

Access Type

Open Access