We propose to study cortical organization and reorganization at the level of neuronal networks and assemblies, using both experimental and theoretical methods. The experimental vehicle will be rat auditory cortex subjected to local electrical stimulation; in analogy to work done by others as well as in our laboratory on somatosensory cortex, this procedure should force changes in the auditory frequency and ear dominance 'map' arrangement. During such changes we propose to make extracellular recordings simultaneously and separably from 10-30 neurons in the reorganizing cortical region. These measurements and their subsequent interpretation in terms of neuronal assembly processes will rest on recording technologies and analytic mathematics that have largely been developed by our laboratory over the last decade. The proposed theoretical work will examine computer simulations of neuronal networks arranged to reproduce the changes in map magnification and boundaries which underlie the experimental work. As information about 'effective connectivity' and neuronal assembly properties emerges from the experiments. these now constraints will be incorporated into the ongoing modeling. The models will be studied on both a gross level, and on a 'microscopic' scale, using our standard spike train analysis techniques, and are likely to suggest additional experimental measurements. The overall project should give considerable insight into actual and possible mechanisms for cortical modularity and reorganization; we will here have direct experimental access to the details of the process by which the brain allocates its computational resources. Comparison of the auditory work to the analogous somatosensory project will test the extent to which the reorganization processes are universal across sensory systems, or conversely whether they will prove to be unique.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Research Project (R01)
Project #
5R01DC001249-02
Application #
2126362
Study Section
Hearing Research Study Section (HAR)
Project Start
1992-09-01
Project End
1996-08-31
Budget Start
1994-09-01
Budget End
1995-08-31
Support Year
2
Fiscal Year
1994
Total Cost
Indirect Cost
Name
University of Pennsylvania
Department
Physiology
Type
Schools of Medicine
DUNS #
042250712
City
Philadelphia
State
PA
Country
United States
Zip Code
19104
Davies, Ronnie M; Gerstein, George L; Baker, Stuart N (2006) Measurement of time-dependent changes in the irregularity of neural spiking. J Neurophysiol 96:906-18
Lindsey, Bruce G; Gerstein, George L (2006) Two enhancements of the gravity algorithm for multiple spike train analysis. J Neurosci Methods 150:116-27
Keating, Jeff G; Gerstein, George L (2002) A chronic multi-electrode microdrive for small animals. J Neurosci Methods 117:201-6
Musial, P G; Baker, S N; Gerstein, G L et al. (2002) Signal-to-noise ratio improvement in multiple electrode recording. J Neurosci Methods 115:29-43
Gerstein, G L; Kirkland, K L; Musial, P G et al. (2002) Recordings, behaviour and models related to corticothalamic feedback. Philos Trans R Soc Lond B Biol Sci 357:1835-41
Talwar, S K; Musial, P G; Gerstein, G L (2001) Role of mammalian auditory cortex in the perception of elementary sound properties. J Neurophysiol 85:2350-8
Gerstein, G L; Kirkland, K L (2001) Neural assemblies: technical issues, analysis, and modeling. Neural Netw 14:589-98
Kisley, M A; Gerstein, G L (2001) Daily variation and appetitive conditioning-induced plasticity of auditory cortex receptive fields. Eur J Neurosci 13:1993-2003
Baker, S N; Gerstein, G L (2001) Determination of response latency and its application to normalization of cross-correlation measures. Neural Comput 13:1351-77
Baker, S N; Gerstein, G L (2000) Improvements to the sensitivity of gravitational clustering for multiple neuron recordings. Neural Comput 12:2597-620

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