Personal HistoryPh.D. 1986, University of Texas Southwestern Medical School in Dallas, Texas Postdoctoral Fellowship in Neuropsychopharmacology 1986-1989, Yale University School of Medicine in New Haven, Conn. Research InterestsOur laboratory is investigating the physiological mechanisms through which dopamine-containing neurons in the ventral midbrain encode information. Located in the pars compacta of the substantia nigra and in the adjacent ventral tegmental area, these cells form reciprocal connections with neurons in the basal ganglia, cortex and limbic forebrain. Dopamine neurons and their circuits are critically involved in the regulation of motor activity and in the motivational processes underlying learning and execution of goal-directed behaviors. Understanding the basic mechanisms involved in regulating the electrical activity of these cells and their neuronal targets is an essential step in the development of new strategies for treating a variety of clinical syndromes including Parkinson's disease, schizophrenia and drug abuse.
Much of our current research is focused on study of the ionic currents that produce the complex firing patterns exhibited by dopamine neurons with an emphasis on those responsible for generating bursting activity. To accomplish this, we use a variety of contemporary electrophysiological and pharmacological techniques including intracellular and extracellular recording, in vitro brain slice techniques, microstimulation and microiontophoresis. Our research has shown that bursts of action potentials are generated intrinsically by a repetitive oscillation in membrane potential driven by voltage dependent calcium channels expressed in the dopamine neurons themselves. Currently, we are examining the interplay between these intrinsic mechanisms and the influence of afferents that contain neurotransmitters and modulators capable of modifying dopamine cell activity. Future studies are aimed at identifying the cellular mechanisms responsible for switching the firing pattern of dopamine neurons between bursting and nonbursting modalities and applying this knowledge to advance our current understanding of the influence of dopamine on target neurons throughout the forebrain. Publications
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