The broad, long-term objective of this proposed research is to develop, analyze and evaluate computer models of small cortical strokes. In particular, the reorganization of neocortical maps following simulated strokes will be examined. This research will thus complement traditional clinical and animal model approaches to studying cerebrovascular disease. It will shed light on the pathophysiology of post-stroke recovery and on the dynamics of neocortical information processing in general. The methods used in this research are as follows. Computer simulations referred to as neural models will be developed for several neocortical regions known to have topographic and computational maps: primary (SI) and secondary (SII) somatosensory cortex, primary (VI) visual cortex, motor (MI) cortex, and area 7a in parietal cortex. In each case it will be demonstrated that topographic or computational maps resembling those observed empirically emerge spontaneously as a result of synaptic modifications occurring during learning in the neural model. By varying each model region's underlying network structure, activation mechanism, learning method, or other parameters, the role of each of these factors in map formation will be examined. Subsequently, each model will be lesioned (""""""""simulated stroke""""""""). The resultant post-lesion map reorganization will be characterized as lesion size and location are systematically varied. This characterization will make testable predictions that can be investigated in future clinical or laboratory studies. This work will be done by a multidisciplinary research group with expertise in neurology, neurophysiology and computer science.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS029414-04
Application #
3416225
Study Section
Special Emphasis Panel (SSS)
Project Start
1990-09-01
Project End
1995-08-31
Budget Start
1993-09-01
Budget End
1994-08-31
Support Year
4
Fiscal Year
1993
Total Cost
Indirect Cost
Name
University of Maryland College Park
Department
Type
Schools of Engineering
DUNS #
City
College Park
State
MD
Country
United States
Zip Code
20742
Shevtsova, N; Reggia, J A (2000) Interhemispheric effects of simulated lesions in a neural model of letter identification. Brain Cogn 44:577-603
Ruppin, E; Revett, K; Ofer, E et al. (1999) Penumbral tissue damage following acute stroke: a computational investigation. Prog Brain Res 121:243-60
Ruppin, E; Ofer, E; Reggia, J A et al. (1999) Pathogenic mechanisms in ischemic damage: a computational study. Comput Biol Med 29:39-59
Revett, K; Ruppin, E; Goodall, S et al. (1998) Spreading depression in focal ischemia: a computational study. J Cereb Blood Flow Metab 18:998-1007
Goodall, S; Reggia, J A; Chen, Y et al. (1997) A computational model of acute focal cortical lesions. Stroke 28:101-9
Reggia, J A; Ruppin, E; Berndt, R S (1997) Computer modeling: a new approach to the investigation of disease. MD Comput 14:160, 162, 164 passim
Chen, Y; Reggia, J A (1996) Alignment of coexisting cortical maps in a motor control model. Neural Comput 8:731-55
Reggia, J A; Montgomery, D (1996) A computational model of visual hallucinations in migraine. Comput Biol Med 26:133-41
Grundstrom, E L; Reggia, J A (1996) Learning activation rules rather than connection weights. Int J Neural Syst 7:129-47
Ruppin, E; Reggia, J A (1995) Patterns of functional damage in neural network models of associative memory. Neural Comput 7:1105-27

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