I graduated from Yale University with a bachelor's degree in Psychology. My long-standing interest in cognition and learning has lead to my current work to understand the cellular processes that underlie mental health and psychiatric disorder. At the University of Pittsburgh, I obtained a Ph.D. in the Department of Neuroscience with Jon Johnson, Ph.D., where I used single-channel recordings to study the mechanisms by which the anti-Parkinsonian and anti-Alzheimer's drugs amantadine and memantine act on NMDA receptors. I then undertook postdoctoral training with George Augustine, Ph.D. and Michael Ehlers, M.D. Ph.D. at Duke University in the Department of Neurobiology. I joined the Department as an Assistant Professor in 2005 , and was promoted to Associate Professor in 2012.
Work in the lab is supported by the NIMH through an R01 and the Presidential Early Career Award for Scientists and Engineers, by a collaborative R01 from NIMH with Sri Raghavachari at Duke University, by the Dana Foundation, and by the Broad Foundation. Past support has come from NARSAD (The Mental Health Research Organization). Recently, the lab was dedicated as the Katherine D. and Theodore J. Carski Memorial Laboratory. Two students have won additional, highly prized support from the NIH by successfully competing for Individual NRSAs.
Research in my lab examines protein trafficking mechanisms at synapses, and seeks to understand how these mechanisms are used to regulate synaptic transmission.
The dendrites of neurons receive and integrate inputs from hundreds or thousands of partner cells, and most of this input arrives at highly specialized sites called synapses that are distributed over the dendritic tree. Improper regulation of synaptic transmission is implicated in an enormous variety of psychiatric disorders: an imbalance of glutamatergic neurotransmission in particular has been identified in the pathophysiology of diseases ranging from schizophrenia and autism to epilepsy and addiction, and increasing evidence suggests that excitatory synapses are among the earliest targets of Alzheimer's Disease (AD) pathogenesis. A key means of synaptic regulation is the control of the number and subsynaptic position of postsynaptic neurotransmitter receptors, and so understanding the mechanisms involved has broad implications not only for understanding the etiology of many diseases but more generally for defining the cellular basis of nervous system function and disorder.
We focus on processes that operate rapidly and very locally to regulate synaptic function on a moment-to-moment basis. These mechanisms are of particular interest because they likely underlie the initial stages of memory formation, and their perturbation produces severe and long-lasting damage to synaptic and neuronal morphology. Mechanisms we are studying currently include the trans-synaptic molecular bridges that align presynaptic nerve terminals with postsynaptic specializations, the continuous internalization and recycling of synaptic receptors, and the postsynaptic actin cytoskeleton that controls postsynaptic morphology and regulates receptor trafficking in many ways.
Understanding the complex set of molecular reactions that underlie endocytosis and other trafficking events requires examining these events in live cells. Thus, the lab has turned to high-resolution, high-speed, multi-color confocal imaging of proteins in cultured neurons as a way of examining the kinetics and spatial features of the molecular events at individual living synapses. We utilize a number of novel fluorescence assays to examine protein positioning and movement at the synapse in living cells at the highest resolution possible. These tools provide the perfect complement to whole-cell and single-channel electrophysiological assays, which naturally track receptor function at high speed but typically with little or no spatial resolution. The lab aims to combine these approaches with molecular perturbation of protein function to provide unprecedented spatial, temporal, and molecular understanding of the protein trafficking events in spines.
Lab Techniques and Equipment:
Most research in the lab revolves around the ability to measure cellular events in real time and in living neurons using fluorescence microscopy and electrophysiology. Recent, enormous advances in microscopy have opened amazing new opportunities to measure and to manipulate molecular events as they happen in the cell. To take advantage of this revolution, the lab will continue developing techniques and analysis to understand how actions at the level of molecules and organelles regulate synaptic transmission and other neuronal functions.
Students and postdocs in the lab can expect to utilize state-of-the-art time-lapse microscopy techniques to visualize receptor trafficking and other forms of protein dynamics, along with simultaneous electrophysiological assays of cell surface receptors and channels. Two super-resolution microscopes in the lab are heavily used for single-molecule-based imagine (PALM and STORM). Confocal microscopy is used to perform photobleaching (FRAP), photoactivation, and energy transfer (FRET) analyses. A variety of molecular techniques are used to tag and alter proteins of interest for live-cell imaging, and lab members will be encouraged to develop biochemical assays to test mechanistic hypotheses outside the cell.
Current lab members
Former lab members
Postdoctoral fellows: We are always seeking talented individuals interested in using super-resolution cellular imaging (PALM) and single-molecule tracking to study cell biological mechanisms of synapse function. Ongoing projects include dynamics of the postsynaptic density and cytoskeletal organization in spines. These are exciting, new lines of work using cutting-edge techniques that require creative development to reach their full potential, and we are looking for motivated and independent scientists who will push the projects forward. Applicants should have a Ph.D. in Neuroscience, Cell Biology, or a related field and have experience and a strong interest in imaging, biophysics, or synaptic transmission. Programming experience or a strong quantitative orientation is a plus. Opportunities for integrating imaging with patch-clamp electrophysiology are available. Postdocs will additionally be expected to apply for further support via individual NRSAs, local training grants, and other sources.