Anna K. Majewska, Ph.D.

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Research: Imaging of synaptic structure and function in the visual system.

My lab uses advanced imaging techniques to study the structure and function of single cells in networks in the intact brain. Although a vast literature describes the development and function of neuronal connectivity, most of this work has been carried out in culture and excised or fixed tissue, where dynamic processes are inferred from static images compared across animals. Little is known about the function of subcellular compartments in the computations carried out by neurons in vivo. The goal of our work is to understand structural and functional changes occurring at synapses during plasticity elicited by sensory stimuli.

My specific interests lie in understanding how visual activity shapes the structure and function of connections between neurons in the visual cortex. During the critical period, closure of one eye leads to a shift in the responses of neurons towards the open eye. My labs current work focuses on the structural basis for this rapid ocular dominance plasticity using in vivo two-photon microscopy to elucidate single cell structure deep in the intact brain. Dendritic spines are the postsynaptic structures of most excitatory synapses in the CNS. Interestingly, spine structure is highly dynamic making the precise morphology of the spine a possible candidate for the coding of synaptic strength. By combining structural two-photon imaging with functional intrinsic signal imaging in the ferret and mouse, we can correlate changes in synaptic structure with changes in response properties of the visual cortex. These experiments have shown increased spine motility as well as increased spine and axon terminal turnover following even one day of monocular deprivation. These synaptic changes occur in the absence of changes in gross dendritic or axonal structure, suggesting that fine scale changes in synaptic connectivity underlie rapid ocular dominance plasticity without an overall remodeling of the pre and postsynaptic scaffold.

My lab is also interested in the mechanisms which underlie structural remodeling at synapses. Imaging carried out in reduced preparations such as the acute brain slice allows us to explore the contributions of different pathways to structural plasticity. Our work has shown that both intracellular pathways and the extracellular matrix are involved in the remodeling of the spine during synaptic plasticity.

Selected peer-reviewed recent publications:

Oray, S., Majewska, A., Sur, M. (2006) Effects of synaptic activity on dendritic spine motility of developing cortical layer 5 pyramidal neurons. Cerebral Cortex 16:730-41.

Majewska, A., Newton, J., Sur, M. (2006) Remodeling of synaptic structure in sensory cortical areas in vivo. J. Neurosci. 26:3021-9.

Majewska, A., Sur, M. (2006) Plasticity and specificity of cortical processing networks. TINS 29:323-9.

Wang, K., Majewska, A., Schummers, J., Farley, B., Hu, C., Sur, M., Tonegawa, S. (2006) The critical role of arc in stimulus-specific activation of neuronal ensembles in visual cortex. Cell 126:389-402.

Deisseroth, K., Feng, G., Majewska, A., Miesenböck, G., Ting, A., Schnitzer, J. (2006) "Next-generation optical technologies for illuminating genetically targeted brain circuits." J. Neurosci. 26:10380-6.

Brown, E., Sullivan, K., Majewska, A. (2009) Single and Multiphoton FRAP. In: Yuste R. and Konnerth A., eds. Imaging in Neuroscience and Development: A Laboratory Manual. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York.

Majewska, A. (2007) Dynamic remodeling of dendritic spines in developmental visual plasticity. Cell Science Reviews 3(3):85-98.

Brown, E., Majewska, A., Jain, R. K. (2008) Photobleaching and Recovery with Nonlinear Microscopy. In: So P., Masters B. (eds) Handbook of Biological Nonlinear Optical Microscopy. Oxford University Press, Oxford UK. Chapter 26, pp. 673-688

Current Appointments

• Assistant Professor - Department of Neurobiology and Anatomy (SMD)
• Assistant Professor - Department of Center for Visual Science (RC)

Education
PhD Neurobiology	Columbia University	2001
MS Biological Science	Stanford University	1996
BS Biological Science	Stanford University	1995

Post-Doctoral Training & Residency
Postdoctoral Fellow, Picower Center for Learning and Memory, Massachusetts Institute of Technology.	2000 - 2005

Fellowship Awards
"In vivo imaging of synaptic structure" Agency: Whiteman Fund	2001 - 2004

Lab Website

http://www.urmc.rochester.edu/labs/Majewska-Lab/

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Recent Journal Articles
Showing the 5 most recent journal articles. (21 available)
Majewska, A. "Dynamic remodeling of dendritic spines in developmental visual plasticity." Journal of Cell Science 3 (2007): 85-98.
Majewska, A.; Newton, J.; Sur, M. "Remodeling of synaptic structure in sensory cortical areas in vivo." J. Neurosci. 26 (2006): 3021-29.
Deisseroth, K., Feng, G., Majewska, A., Miesenböck, G., Ting, A., Schnitzer, J. ""Next-generation optical technologies for illuminating genetically targeted brain circuits."". J. Neurosci. 26 (2006): 10380-86.
Wang, K., Majewska, A., Schummers, J., Farley, B., Hu, C., Sur, M., Tonegawa, S. "The critical role of arc in stimulus-specific activation of neuronal ensembles in visual cortex." Cell 126 (2006): 389-402.
Majewska, A., Sur, M. "Plasticity and specificity of cortical processing networks." TINS 29 (2006): 323-9.