Anatomy and Neurobiology
Vice Chair, Department of Anatomy and Neurobiology
Education and Training
I received my Ph.D. from the Department of Anatomy and Cell Biology at the University of Melbourne (Australia) working with Dr. Brian Key on the role of cell-surface carbohydrates in axon guidance within the olfactory system. I then moved to the U.S. to conduct post-doctoral work with Dr. Michael T. Shipley at the University of Maryland. I remained at the University of Maryland School of Medicine as tenured faculty in the Department of Anatomy and Neurobiology.
All animals from simple single cell organisms through complex vertebrates detect and react to chemicals/odors in their external environment, some at concentrations of only a few parts per million. These environmental odors are generally complex mixtures of individual chemicals/odorants; coffee, for example, may contain as many as 1000 separate chemicals/odorants. The olfactory system, therefore, must be capable of detecting and identifying diverse odorant mixtures. Research in our laboratory focuses upon on understanding how the olfactory system develops during embryogenesis, early postnatal life, and functions in adulthood.
Individual axons of olfactory receptor neurons (ORNs) located in the epithelium lining the nasal cavity project to the olfactory bulb where they synapse on the dendrites of interneurons and projection neurons within globular structures of neuropil - glomeruli. Continual neurogenesis of olfactory interneurons in the subventricular zone of postnatal and adult forebrain has been well documented, but the mechanisms underlying cell migration/differentiation from this region are poorly understood. Most of the cells generated in this region migrate tangentially along the rostral extension of the SVZ into the olfactory bulb, following a well-defined pathway, the "rostral migratory stream". Upon reaching the core of the OB, the cells migrate radially, where most assume the morphology of interneurons. Using a combination of neuroanatomical, surgical, tissue culture, and molecular approaches we are investigating the migration and differentiation of these cells.
Following the formation of glomeruli, the synaptic circuitry underlying how the brain interprets and regulate the processing of sensory information, specifically the sense of smell, at the first site processing of olfactory information in the brain remains only partially understood. Neuronal microcircuits, such as the glomerular circuit, are fundamental processes that regulate brain activity and this basic research will hopefully provide building blocks for understanding higher order processes. Using a combination of extracellular recording, intracellular whole cell patch recording, calcium imaging, deep brain miniature endoscopic imagine and cell labeling we are working to characterize the cellular, membrane, pharmacologic and network properties of intra- and interglomerular neural processing.
Olfactory, neuroanatomy, neurophysiology, imaging
Course director for MSRP512 "Structure and Development", the first year medical school course covering gross anatomy, histology and embryology studies.