Anatomy and Neurobiology
I was trained in Biomedical Engineering as an undergraduate at The Johns Hopkins University. Following a Masters in Chemical Engineering designing polymer substrates for neural regeneration, I pursued an interdisciplinary doctoral program in Chemical Engineering and Developmental Biology at Rutgers with Dr. Herbert Geller. I received my postdoctoral training with Dr. Pat Levitt at the University of Pittsburgh.
Behaviors are the final output of brain circuitry, and the formation of inappropriate connections can lead to unique manifestations such as observed during autism, mood disorders and schizophrenia. The causes of many of these conditions can be attributed to defects in GABA producing interneurons. My lab studies the molecular and cellular mechanisms of forebrain GABAergic interneurons: What specifies their cell fate? How do they migrate to their final destination? And what factors regulate interneuron differentiation and circuit formation?
We have found that the family of plasminogen activators, classically responsible for dissolving blood clots, and the plasminogen related growth factors (including hepatocyte growth factor/scatter factor (HGF/SF)) are critical components of interneuron development. In transgenic mutant mice, the lack of these molecules results in interneuron loss and behaviors similar to human epilepsy, autism and anxiety disorders.
The laboratory uses a wide variety of approaches from the molecular level to animal behavioral testing to explore how developmental alterations lead to adult neurological and psychiatric disorders. Our long-term goals include designing interventions to prevent or ameliorate these conditions.
Lab Techniques and Equipment:
- Histology and Imaging: Immunohistochemistry, dye-tracing, digital imaging, confocal microscopy, live cell imaging
- Molecular biology: Cloning, Southern and Northern blot analysis, PCR, in situ hybridization
- Biochemistry: Western blots, protein purification, ELISA assays, phosphorylation assays, enzyme assays, differential fractionation
- Cell and tissue culture: Explant cultures, transfection of cells and tissues, cell migration assays, neurite outgrowth assays
- Behavior: Open field analysis, anxiety testing: light-dark avoidance, elevated plus maze, social behavior testing, learning and memory testing
- Transgenic animal analysis: Creation and maintenance of knock-out, knock-in, targeted mutation (cre-loxp recombination), and reporter (lacZ and GFP) lines
The laboratory has several openings for technicians, graduate students and postdoctoral fellows. Please email your cv/resume.
HGF/SF During Development:
A reduction in HGF/SF during development leads to autistic-related deficits. Mutant mice do not exhibit normal social interactions in the resident intruder tests. These animals also show increased anxiety and spontaneous seizures (epilepsy).
- Levitt, P, Eagleson KE, Powell, EM. “Regulation of neocortical interneuron development and implications for neurodevelopmental disorders”. TINS 27:400-6 (2004).
- Powell, EM, Muhlfriedel, S, Bolz, J, and Levitt, P, “Differential regulation of thalamic and cortical axonal growth by Hepatocyte Growth Factor/Scatter Factor,” Dev. Neuriosci. 25(2-4):197-206 (2003).
- Powell, EM, Campbell, DB, Stanwood, GD, Davis, C, Nobels, JL, and Levitt, P, “Genetic disruption of cortical interneuron development causes region- and GABA cell type-specific deficits, epilepsy, and behavioral dysfunction,” J Neurosci. 23(2):622-31. (2003).
- Powell, E.M., Mars, W. M., and Levitt, P., “Hepatocyte growth factor/scatter factor is a motogen for interneurons migrating from the ventral to dorsal telencephalon. Neuron 30(1):79-89 (2001).
- Powell, E.M., Mercado, M.L., Thornton, S.R., and Geller, H.M., “Protein kinase C mediates neurite guidance at an astrocyte boundary,” GLIA 33(4):288-97 (2001).
- Meiners, S., Powell EM., and Geller HM. “Neurite outgrowth promotion by the alternatively spliced region of tenascin-C is influenced by cell-type specific binding. Matrix Biology. 18(1):75-87 (1999).
- Powell, E.M. and Geller, H.M., “A dissection of astrocyte-mediated cues in neuronal guidance and process extension,” GLIA 26(1):73-83, (1999).
- Powell, E.M., Fawcett, J.W., and Geller, H.M., “Neurite guidance by astrocyte proteoglycans,” Mol. Cell. Neurosci. 10:27-42 (1997).
- Powell, E.M., Meiners, S., Di Prospero, N.A., and Geller, H.M., “Mechanisms of astrocyte directed neurite guidance,” Cell Tiss. Res. 290:385-393 (1997).
- Meiners, S., Powell, E.M., and Geller, H.M., “A distinct subset of tenascin/CSPG-rich astrocytes restricts neuronal growth in vitro,” J. Neurosci. 15:8096-8108 (1995).
- Okoye, G.S., Powell, E.M., and Geller, H.M., “Migration of immortalized cells grafted into the adult striatum,” J. Comp. Neurol. 363:1-11 (1995).
- Powell, E.M., Sobarzo, M.R., and Saltzman, W.M., “Controlled release of nerve growth factor from a polymeric implant,” Brain Res. 515:391-393 (1990).