Sensory neocortex: structure, function and plasticity
Our main research focus is the structure and function of sensory cortex with special emphasis on plasticity (its ability to change its structure and function). We believe that plasticity is a fundamental property that underlies both normal cortical function (from sensory processing to learning and memory) and cortical recovery from deprivation and injury. We therefore seek to investigate all of these aspects of plasticity.
Our research philosophy is to study sensory cortex using an integrative, in-vivo approach. The integrative approach entails studying the cortex at multiple levels and at different temporal and spatial scales- including behavior, neuronal assemblies, neuronal circuits, neurovascular interactions, single neurons, molecules and genes, and therefore calls for the application of multiple techniques. These include high-resolution functional imaging, blood-flow imaging, modulated imaging, neuronal recording with electrode arrays, neuronal tract-tracing, histology, pharmacology, genetic manipulations and behavioral techniques.
Our animal model is the rodent sensory cortex (mice and rats). Most of our research in recent years has been focused on the somatosensory system, especially the popular 'barrel cortex' sub-region that contain exquisite anatomical and functional 'maps' of the facial whiskers representations. Currently, we are also expanding to other sensory systems including the auditory and visual cortices.
Examples of current research projects:
(1) A novel view of the functional and structural organization of the rodent somatosensory cortex. This view is based on the finding about large, symmetrical spread of evoked activity following single whisker stimulation and its underlying support by a plexus of long-range horizontal neuronal projections. Both activity spreads and neuronal projections are so large that they ignore the borders of primary somatosensory cortex and spill into other cortical modalities such as primary visual and primary auditory cortices.
(2) A new type of neurovascular plasticity: how stimulation of a single whisker for few minutes can completely protect the cortex from an impending ischemic stroke; suggesting a new role for evoked cortical activity in complete protection from stroke.
(3) Functional, structural and molecular plasticity induced by transferring rodents from their standard home cages to our ‘naturalistic habitat’- an environment created to promote naturalistic behavior in rats like tunnel digging, foraging, and social interactions that cannot be expressed in the standard cage.
Lay, C., Davis, M.F., Chen-Bee, C.H. and Frostig R.D. Mild sensory stimulation re-establishes cortical function during the acute phase of ischemia. Journal of Neuroscience, 31:11495-11504, 2011
Davis, M.F., Lay, C., Chen-Bee, C.H. and Frostig, R.D. Amount But Not Pattern Of Protective Sensory Stimulation Alters Recovery After Permanent Middle Cerebral Artery Occlusion. Stroke, 42; 792-798, 2011.
Lay, C., Davis, M.F., Chen-Bee, C.H. and Frostig, R.D. Mild sensory stimulation completely protects the adult rodent cortex from ischemic stroke. PLoS-ONE, 5(6): e11270. doi:10.1371/journal.pone.0011270, 2010.
Frostig, R.D., Xiong, Y, Chen-Bee, C.H., Kvasnak, E., and Stehberg, J. Large-scale organization of rat sensorimotor cortex based on a motif of large activation spreads. Journal of Neuroscience, 28(49):13274-13284, 2008.
Chen-Bee, C.H., Agoncillo, T., Xiong, Y., and Frostig, R.D., The tri-phasic intrinsic signal: implications for functional imaging. Journal of Neuroscience, 27 (17): 4572 - 4586, 2007.
Frostig, R.D. Functional organization and plasticity in the adult rat barrel cortex: moving out-of-the-box. Current Opinion in Neurobiology, 16, 445-50, 2006.
Polley, D.B., Rickert, J., and Frostig, R.D. Whisker-based discrimination of object orientation determined with a rapid training paradigm. Neurobiology of Learning and Memory, 83, 134-142, 2005.
Polley, D.B., Kvasnak, E., and Frostig, R.D. Naturalistic experience transforms sensory maps in the adult cortex of caged animals. Nature, 429:67-71, 2004.
Neurobiology and Behavior
Interdepartmental Neuroscience Program