The goal of our activity is to understand the mechanisms underlying plastic changes in the human central nervous system and develop novel therapeutic approaches for recovery of function based on these advances. Most of our work has focused in plasticity of the human motor system and plasticity across sensory modalities (blindness). This year, we identified the window of opportunity for development of cross-modal plasticity in blind individuals. Individuals that became blind after age 13 years experience different and more moderate types of plastic changes. In the visual domain, we found that administration of 1hz repetitive transcranial magnetic stimulation can decrease the excitability of the human occipital cortex, a finding potentially relevant in the treatment of seizure disorders. In relation to use- dependent plasticity in motor cortex, we discovered that it is possible to block it by the administration of the NMDA-receptor antagonist dextromethorphan and by lorazepam, identifying LTP-like mechanisms as likely to operate in this form of plasticity. We also developed two ways 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 plasticity in the human motor cortex of amputees is larger 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 mechanisms, time- profile and site where plasticity takes place after a variety of disorders. Our future goals are to improve our understanding of the mechanisms underlying plasticity of function in humans and its functional relevance. On the basis of these mechanisms, we are starting to design and test interventions to improve motor disability after human diseases. - plasticity,stroke,rehabilitation,motor,physiology,treatment, - Human Subjects & Human Subjects: Interview, Questionaires, or Surveys Only

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Intramural Research (Z01)
Project #
1Z01NS002978-01
Application #
6228069
Study Section
Special Emphasis Panel (MNB)
Project Start
Project End
Budget Start
Budget End
Support Year
1
Fiscal Year
1999
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 :
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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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