The goal of our activity is to understand the functional role and substrates underlying plastic changes in the human central nervous system and develop novel therapeutic approaches for recovery of function. Most of our work has focused on the study of plastic changes in the human motor, somatosensory and visual systems. This year, we identified behavioralgains in tactile discriminative skills in one hand associated with deafferentation in the other hand. In the visual domain, we found that light deprivation is associated with an increase in excitability of the visual cortex and a decrease in GABA levels in that region. This finding demonstrates the possibility of online monitoring minute to minute of changes in cortical GABA in behaving humans using magnetic resonance spectroscopy. In relation to use- dependent plasticity in motor cortex, we discovered that it is possible to modulate plasticity in one body part representation by stimulation with TMS and by stimulation of adjacent body part representations. We also developed two strategies to enhance use-dependent plasticity: by administration of d-amphetamine and also by concomitant administration of transacranial magnetic stimulation. In a collaborative effort with German investigators, we found that representational plasticity in somatosensory and motor cortex is more prominent in patients with phantom limb pain than in amputees without pain. In the area of rehabilitation after chronic stroke, we found that a rehabilitation treatment called """"""""constraint induced therapy"""""""" appears to enhance the amount of use of the paretic arm long time after stroke. We have advanced in the understanding of the involvement of the intact hemisphere and nonprimary motor areas (particularly dorsal premotor cortex) in recovery of motor function after stroke. Our future goals are to improve our understanding of the functional role and substrates underlying plasticity of function in humans. On the basis of this understanding, we are starting to design and test interventions to improve motor disability after human diseases.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Intramural Research (Z01)
Project #
1Z01NS002978-04
Application #
6671403
Study Section
(HCPS)
Project Start
Project End
Budget Start
Budget End
Support Year
4
Fiscal Year
2002
Total Cost
Indirect Cost
City
State
Country
United States
Zip Code
Perez, Monica A; Cohen, Leonardo G (2009) Interhemispheric inhibition between primary motor cortices: what have we learned? J Physiol 587:725-6
Sehm, B; Perez, M A; Xu, B et al. (2009) Functional Neuroanatomy of Mirroring during a Unimanual Force Generation Task. Cereb Cortex :
Ragert, Patrick; Camus, Mickael; Vandermeeren, Yves et al. (2009) Modulation of effects of intermittent theta burst stimulation applied over primary motor cortex (M1) by conditioning stimulation of the opposite M1. J Neurophysiol 102:766-73
Schaefer, Michael; Xu, Benjamin; Flor, Herta et al. (2009) Effects of different viewing perspectives on somatosensory activations during observation of touch. Hum Brain Mapp 30:2722-30
Reis, Janine; Robertson, Edwin; Krakauer, John W et al. (2008) Consensus: ""Can tDCS and TMS enhance motor learning and memory formation?"" Brain Stimulat 1:363-369
Dimyan, Michael A; Dobkin, Bruce H; Cohen, Leonardo G (2008) Emerging subspecialties: neurorehabilitation: training neurologists to retrain the brain. Neurology 70:e52-4
Mazzocchio, Riccardo; Meunier, Sabine; Ferrante, Simona et al. (2008) Cycling, a tool for locomotor recovery after motor lesions? NeuroRehabilitation 23:67-80
Kim, Jee Hyun; Lee, Hyang Woon; Cohen, Leonardo G et al. (2008) Motor cortical excitability in patients with poststroke epilepsy. Epilepsia 49:117-24
Nielsen, Jens Bo; Cohen, Leonardo G (2008) The Olympic brain. Does corticospinal plasticity play a role in acquisition of skills required for high-performance sports? J Physiol 586:65-70
Floel, A; Garraux, G; Xu, B et al. (2008) Levodopa increases memory encoding and dopamine release in the striatum in the elderly. Neurobiol Aging 29:267-79

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