Ron D. FrostigProfessor, Neurobiology and Behavior |
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Research Interests |
Functtional imaging of cortical plasticity | |
| URL | frostiglab.bio.uci.edu/ | |
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Research Abstract |
Our main research interest lies in addressing fundamental questions regarding the working of the sensory cortex. Specifically, how do large and dynamic assemblies of interacting neurons process sensory information? How do such assemblies form cortical "maps" that represent the sensory world? What mechanisms underlie the ability of the cortex to continuously modify those maps (plasticity) in relation to changes in the animal's sensory patterns, changes in the animal’s environment or changes in the animal’s behavior? To what level are the rules that govern the function, structure and plasticity of the cortex already defined in the genetic blueprint? What are the physiological, anatomical and pharmacological mechanisms that underlie cortical plasticity? To address these questions, we study the living cortex at multiple levels of investigation starting at a population level (functional representations, maps) that includes thousands of neurons and progressively refining the investigation to the level of single neurons. To study the functional organization and plasticity at the population level we use Intrinsic Signal Optical Imaging, a technique that is non-invasive to the cortex and that allows imaging of cortical activity over large cortical areas with very high spatial resolution (~50 microns). Because we can image cortical activity through the intact skull, we are able to image the same animal repeatedly over time periods ranging from minutes to months. This ability to image chronically from an animal provides us with the unique ability to visualize the dynamics of cortical activity before, during and after manipulations. Three main types of manipulations have thus far been used in our laboratory: Sensory-behavioral manipulations, pharmacological manipulations and genetic manipulations. Sensory-behavioral manipulations: We found that allowing adult rats to investigate a new environment outside their standard home cage induces dramatic functional plasticity in the adult somatosensory cortex. Such plasticity was found following either a few minutes outside the cage in sensory deprived rats or after a month of living in a naturalistic habitat (a new type of environment that imitates the rats' natural habitat) for normal non-deprived rats. Pharmacological manipulations: We have imaged adult cortical plasticity induced by direct application of drugs that can modify the neurochemistry of the cortex. Specifically, we have studied fast (minutes) functional plasticity is induced by applying Neurotrophins to the adult cortex and also fast plasticity induced by agonists and antagonists of the cholinergic system. Genetic manipulations: We have studied adult cortical plasticity induced by manipulation of genes in the mouse’s genome. Specifically, we studied functional and anatomical plasticity induced by knocking out the Ephrin A5 gene. Imaging projects are complemented by post-imaging single unit-recordings using single microelectrodes or microelectrode arrays and also post-imaging anatomical studies. We believe that the combination of techniques and levels of study provides us with unique insights into the nature of cortical function, structure and plasticity. Current research projects include: 1) Searching for functional and structural mechanisms that underlie developmental and adult cortical plasticity that is induced by living in a naturalistic habitat, and 2) Incorporation of new optical imaging technologies (collaboration with researchers at the Beckman Laser Institute at UCI) for our research projects. |
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| Publications | 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. | |
| Prakash, N., Cohen-Cory, S., Penschuck, S. and Frostig, R.D. The basal forebrain cholinergic system is involved in rapid nerve growth factor (NGF)-induced plasticity in the barrel cortex of adult rats. Journal of Neurophysiology, 91:424-437, 2004. | ||
| Penschuck, S., Chen-Bee, C., Prakash, N., and Frostig, R.D. In vivo modulation of a cortical functional sensory representation shortly after topical cholinergic agent application. Journal of Comparative Neurology, 452, 38-50, 2002. | ||
| Brett-Green, B., Chen-Bee, C.H., and Frostig, R.D. Comparing the functional representations of central and border whiskers in the rat primary somatosensory cortex. Journal of Neuroscience, 15: 9944-9954, 2001. | ||
| Prakash, N., Vanderhaeghen, P., Cohen-Cory, S., Frisén., J., Flanagan, J.G., Frostig, R.D.Malformation of the functional organization of somatosensory cortex in adult ephrin-A5 knockout mice revealed by in vivo functional imaging. Journal of Neuroscience, 20:5841-5847, 2000. | ||
| Vanderhaeghen, P., Lu, Q., Prakash, N., Frisen, J., Walsh, C.A., Frostig, R.D., Flanagan, J.G. A mapping label required for normal scale of body representation in the cortex. Nature Neuroscience, 3:358-365, 2000. | ||
| Chen-Bee, C., Polley, D.B., Brett-Green, B., Prakash, N., Kwon, M.C. and Frostig, R.D. Visualizing and quantifying evoked cortical activity assessed with intrinsic signal imaging. Journal of Neuroscience Methods, 97:157-173, 2000. | ||
| Polley, D.B., Chen-Bee, C., and Frostig, R.D. Two directions of plasticity in the sensory-deprived adult cortex. Neuron, 24:623-637, 1999. | ||
| Polley, D.B., Chen-Bee, C. and Frostig, R.D. Varying the degree of single whisker stimulation differentially affects phases of intrinsic signals in rat barrel cortex. Journal of Neurophysiology, 81:692-701, 1999. | ||
| Prakash, N, Cohen-Cory, S. and Frostig, R.D. Rapid and opposite effects of BDNF and NGF on the functional organization of the adult cortex in vivo. Nature, 381: 702-706, 1996. | ||
| Bakin, J.S., Kwon, M.C., Masino, S.A., Weinberger, N.M. and Frostig, R.D. Suprathreshold auditory cortex activation visualized by intrinsic signal optical imaging. Cerebral Cortex, 6, 120-130, 1996. | ||
| Masino, S.A. and Frostig, R.D. Quantitative long-term imaging of the functional representation of a whisker in rat barrel cortex. Proceedings of the National Academy of Science USA, 93, 5022-5027, 1996. | ||
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Professional Societies |
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| Graduate Programs |
Neurobiology and Behavior Interdepartmental Neuroscience Program |
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| Link to this profile | http://www.faculty.uci.edu/profile.cfm?faculty_id=2395 | |
| Last updated | 07/04/2005 | |