John Walsh
Ph.D.
Associate Professor of Gerontology
John Walsh, Ph.D., is an Associate Professor of Gerontology and
a member of the Neuroscience Program at USC. He received his undergraduate
degree in biology from the University of California, Irvine, and
was awarded a Ph.D. in physiology and biomedical sciences from the
University of Texas School of Medicine in Houston. Dr. Walsh's research
focuses on the electrophysiological analysis of brain areas that
are targets of age related disease. Studies on aging, calcium, and
free radical physiology are performed in Dr. Walsh's laboratory
as they relate to changes in synaptic plasticity and cell behavior.
His research also examines how toxic environmental challenges affect
nerve cell populations typically lost in Parkinson's disease, Huntington's
disease, and Alzheimer’s disease.
"The focus of my laboratory is to understand dopamine and glutamate synaptic physiology in the striatum under normal and pathological conditions. We use the analysis of short and long-term synaptic plasticity at corticostriatal synapes to study striatal pathology and rely upon, whole cell voltage clamp, intracellular and field potential recordings in the analysis. We also use fast-cyclic voltammetry to study dopamine physiology in the same brain slices. A parallel study is being performed in aged animals to describe how aging impacts synaptic integration and the mechanisms for any observed changes caused by the aging process.
A second interest in the laboratory is to describe the modulation of synaptic function and key conductances in striatal neurons following the generation of reactive oxygen species (ROS) under conditions of hypoxia. Part of this NIH funded study uses the complex II inhibitor 3-nitropropionic acid (3-NP) to examine acute and long-term survival and the synaptic consequences of chemical hypoxia.
We also have been studying the impact of MPTP treatment on striatal physiology in mice and squirel monkeys in collaboration with Drs. Mike Jakowec and Giselle Petzinger from USC's Department of Neurology.
These research interests are connected by the underlying hypotheses that aging and disease create shifts in ROS homeostasis, which possibly follow similar pathways in the striatum."
Dr. Walsh spends his free time surfing in southern Orange County.
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