Human Cortical Physiology and Stroke Neurorehabilitation Section - Division of Intramural Research

Leonardo G. Cohen, M.D., Senior Investigator

Dr. Cohen received his MD from the University of Buenos Aires. He did his neurology residency at Georgetown University and received postdoctoral training in clinical neurophysiology at the Department of Neurology, University of California (Irvine) and in motor control and movement disorders at the Human Motor Control Section, NINDS. In 1998 he became chief of the Human Cortical Physiology Section, NINDS. He received the prestigious Humboldt award (1999) from the Republic of Germany and is an elected member of the American Neurological Association. Dr. Cohen's lab is interested in the mechanisms underlying plastic changes in the human central nervous system and in the development of novel therapeutic approaches for recovery of function based on the understanding of these mechanisms.

Laboratory Staff

Nitzan Censor, Ph.D., Postdoctoral Fellow
Eran Dayan, Ph.D., Postdoctoral Fellow
Michael Dimyan, M.D., Clinical Fellow
Susan Schwerin, Ph.D., Predoctoral Fellow
Nikhil Sharma, MB, MRCP(UK), PhD, Clinical Postdoctoral Fellow
Sylvie Song, Ph.D., Predoctoral Fellow
Mari Tobita, M.D., Clinical Fellow
Rita Volochayev, Ph.D., Nurse Practitioner
Benjamin Xu, Ph.D., Staff Scientist
Leonardo G. Cohen Staff Image

Research Interests

The goal of our activity is to understand the mechanisms underlying plastic changes in the human central nervous system (CNS) and to develop novel therapeutic approaches for recovery of function based on these advances. Our work has focused on the human motor system and on plastic changes taking place across sensory modalities for example in blind individuals (crossmodal plasticity). We have studied cortical reorganization in patients with CNS lesions in particular stroke and traumatic brain injury. In healthy volunteers, we studied cortical plasticity associated with deafferentation and motor skill learning.

We utilize different techniques in the context of well defined hypothesis-driven investigations including transcranial magnetic (TMS, video) and DC (tDCS) stimulation, fMRI, TMS in combination with fMRI, MR spectroscopy, diffusion tensor imaging (DTI), PET scanning and magnetoencephalography (MEG). We are interested in the development of these techniques to help us to understand mechanisms of human plasticity and to modulate human brain processes. Our research protocols in healthy volunteers are geared to identify mechanisms of human neuroplasticity and to develop interventional approaches to enhance them when they play a beneficial role and down-regulate them when they are maladaptive. Advances in this understanding in healthy volunteers are subsequently applied to patients with neurological conditions like stroke in attempts to enhance neurorehabilitative processes. In blind individuals, we seek to understand the mechanisms underlying the remarkable compensatory processes involved in crossmodal plasticity, and to facilitate them using noninvasive techniques.

Our future goals are to improve our understanding of mechanisms underlying plasticity of function in humans. On the basis of these insights, we are engaged in translational efforts to develop rational rehabilitative interventions to improve motor disability after stroke in particular using peripheral nerve stimulation, TMS and tDCS. In patients with severe hand paralysis, we use an MEG-based brain computer interface to control grasping motions of an orthosis attached to the paralyzed hand (video).

Clinical Protocols

Neural substrates of lasting motor skill learning by spacing effect 07-N-0072
Human Cortical Physiology Section Repository Protocol 09-N-0156
Screening Protocol for Patients with Stroke 10-N-0012
Interhemispheric Interactions Associated with Performance of Voluntary Movements in Patients with Stroke Motor Disability 02-N-0104
Long-term improvement in training effects by transcranial DC stimulation 06-N-0138
Modulation of motor function by stimulation of the central and peripheral nervous system. 07-N-0122
Moving a paralyzed hand through a brain computer interface controlled by the affected hemisphere after stroke or traumatic brain injury 02-N-0104
Enhancing the beneficial effects of upper extremity visuomotor training with tDCS 09-N-0021
Neural Dynamics and Connectivity in Response Inhibition and Traumatic Brain Injury 10-N-0185
Neuroimaging studies of motor learning in healthy volunteers and patients with brain injury T-N-1175

Selected Recent Publications

Buch ER, Shanechi AM, Fourkas AD, Weber C, Birbaumer N and LG Cohen
Parietofrontal integrity determines neural modulation associated with grasping imagery after stroke, Brain, 2011
Song S, Sharma N, Buch E and LG Cohen
White Matter Microstructural Correlates of Superior Long-term Skill Gained Implicitly under Randomized Practice, Cerebral Cortex, 2011 Full Text/Abstract
Dayan E and LG Cohen
Neuroplasticity subserving motor skill learning, Neuron, 2011, vol. 72, pp. 443-454. Full Text/Abstract
Dimyan MA and LG Cohen
Neuroplasticity in the context of motor rehabilitation after stroke., Nature Reviews Neurology, 2011, vol. 7, pp. 76-85. Full Text/Abstract
Abe M, Schambra H, Wassermann EM, Luckenbaugh D, Schweighofer N and LG Cohen
Reward improves long-term retention of a motor memory through induction of offline memory gains., Current Biology, 2011, vol. 21, pp. 557-62. Full Text/Abstract
Censor N, Dimyan M. A. and L. G. Cohen
Primary cortical processing during memory reactivation enables modification of existing human motor memories, Current Biology, 2010, vol. 20, pp. 1545-9.
Fritsch B, Reis J, Martinowich K, Schambra HM, Ji Y, Cohen LG, Lu B.
Direct current stimulation promotes BDNF-dependent synaptic plasticity: potential implications for motor learning., Neuron, 2010, vol. 66(2), pp. 198-204. Full Text/Abstract
Perez M and LG Cohen
Activity-dependent changes in motor cortical circuits ipsilateral to a moving hand, Journal of Neuroscience, 2008, vol. 28, pp. 5631-40. Full Text/Abstract

Selected Earlier Publications

Contact Information

Chief, Human Cortical Physiology and Stroke Neurorehabilitation Section.
National Institute of Neurological Disorders and Stroke
NIH
Building 10, Room 7D54
Bethesda, MD 20892

Telephone: 301-496-9782 (office), 301-402-7010 (fax)
Email: cohenl@ninds.nih.gov