简介

Dopamine is a neurotransmitter in the brain that is involved with a variety of functions, including motor control, sensory-motor integration, motivation and drive, reward mechanisms, and endocrine control. Knowledge of how dopamine levels are regulated and controlled is important for understanding these functions. Brain dopamine systems have also been linked to various diseases, such as Parkinson's disease, and are a primary target for many drugs of abuse, particularly the psychomotor stimulants such as cocaine and methamphetamine. The focus of my research is on characterizing the mechanisms involved with the regulation and modulation of dopamine release and reuptake in the brain in normal animals, in aged animals, and in animal models of neurodegenerative diseases. Recent studies have involved examination of potential neuroprotective agents in Parkinson’s disease models and in rodent models of methamphetamine neurotoxicity, and the development and characterization of novel models of Parkinson's disease. Rats treated with dopaminergic toxins are similar, in many respects, to humans with Parkinson's disease. We are presently characterizing changes in dopamine function in several animal models and are evaluating the ability of neurotrophic factors to promote behavioral recovery and to return dopaminergic activity to more normal levels. In other projects we are examining the neuroprotective and restorative effects of calcitriol, the active metabolite of vitamin D, in models of dopamine neuron degeneration, and we are finding promising results both in animal models of Parkinson's disease and in models of methamphetamine toxicity. The results of these studies should increase our understanding of changes in brain dopamine systems in Parkinson's disease and drug abuse and could lead to improved treatment strategies for persons with these diseases.