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 in the Department of Anatomy & Neurobiology at the University of Maryland School of Medicine, where I am now pursuing a career as an Associate Professor.
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 and early postnatal life.
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 second-order neurons within globular structures of neuropil - glomeruli. It was recently discovered that all of the axons from ORNs expressing the same odorant receptor gene converge onto two (or a few) glomeruli in the bulb. The location of these glomeruli is bilaterally symmetrical and invariant across animals. However, little is understood about the mechanisms in the olfactory bulb governing such precise topographical targeting by ORN axons. Part of our research program focuses upon studying these mechanisms using a combination of tissue culture, histology and in vivo model systems.
Continual neurogenesis 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 dendrites of second order mitral/tufted cells dramatically rearrange their dendritic arbor from having multiple apical dendrites to having a single apical dendrite restricted to one glomerulus. Part of our ongoing collaborations look at changes in morphology, electrophysiology, and gene expression in these neurons as they develop using neuroanatomical, neurophysiology and molecular biology techniques.
Lab Techniques and Equipment:
Tissue culture (including dissociated neurons, explant culture, organotypic slices, cell migration imaging); Histology (including immunohistochemistry, neuroanatomy, tract tracing, in situ hybridization, and confocal microscopy); Molecular biology (including single cell/small tissue isolation and gene analysis), and in vivo surgery models (including injections, lesions, and transplants).
Collaborative studies involve whole cell/field potential electrophysiology, and voltage sensitive dye/calcium sensitive dye imaging.
There is currently one position open for a post-doctoral fellow or research assistant to work on cell migration in the olfactory system. Salaries commensurate with experience. Familiarity with neuroanatomical/immunohistochemical, tissue culture, live slice imaging are advantages. If interested, contact or send a CV to firstname.lastname@example.org.
- Drs. Michael Shipley and Phillip Heyward- On the neurophysiology of mitral and tufted cells in the developing olfactory bulb.
- Drs. Frank Margolis and Patrizia Bovolin - On molecular cloning and expression studies in the olfactory bulb.
- Drs. Matthew Ennis and Asaf Keller - On the neurophysiology of olfactory bulb to piriform cortex circuits.
- Drs. Frank Zufall and Trese Leinders-Zufall- On calcium imaging of olfactory receptor neuron responses to odors and pheromones.
- Drs. Tae Oh and George Markelonis - On the growth promoting properties of olfactory ensheathing cells.
- De Marchis, S., Fasolo, A., Shipley, M.T., and Puche, A.C. (2001) Unique neuronal tracers show migration and differentiation of SVZ progenitors in organotypic slices. J. Neurobiol. 49:326-338.
- Puche, A.C., and Shipley, M.T. (2001) Radial Glia Development in the Olfactory Bulb: A Role in Glomerular Formation? J. Comp. Neurol. 434:1-12.
- Puche, A.C., and Shipley, M.T. (1999) Odor-Induced, activity-dependent transneuronal gene induction in vitro: Mediation by NMDA receptors. J. Neurosci. 19:1359-1370.
Links of Interest:The Olfactory Image Archive
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