title: Spike-timing-dependent plasticity in primate corticospinal connections induced during free behavior.
abstract: Motor learning and functional recovery from brain damage involve changes in the strength of synaptic connections between neurons. Relevant in vivo evidence on the underlying cellular mechanisms remains limited and indirect. We found that the strength of neural connections between motor cortex and spinal cord in monkeys can be modified with an autonomous recurrent neural interface that delivers electrical stimuli in the spinal cord triggered by action potentials of corticospinal cells during free behavior. The activity-dependent stimulation modified the strength of the terminal connections of single corticomotoneuronal cells, consistent with a bidirectional spike-timing-dependent plasticity rule previously derived from in vitro experiments. For some cells, the changes lasted for days after the end of conditioning, but most effects eventually reverted to preconditioning levels. These results provide direct evidence of corticospinal synaptic plasticity in vivo at the level of single neurons induced by normal firing patterns during free behavior.
authors.affiliation: Department of Physiology & Biophysics and Washington National Primate Research Center, University of Washington, Seattle, WA 98195-7290, USA; Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency, Chiyoda, Tokyo 102-0076, Japan. Electronic address: yukio@nips.ac.jp.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Nishimura
authors.forename: Steve I
authors.initials: SI
authors.lastname: Perlmutter
authors.forename: Ryan W
authors.initials: RW
authors.lastname: Eaton
authors.forename: Eberhard E
authors.initials: EE
authors.lastname: Fetz
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000704:Analysis of Variance; D000818:Animals; D001703:Biophysics; D002940:Circadian Rhythm; D004558:Electric Stimulation; D004576:Electromyography; D008254:Macaca nemestrina; D008297:Male; D009046:Motor Neurons / Q000502:physiology*; D009415:Nerve Net / Q000502:physiology; D009433:Neural Inhibition / Q000502:physiology; D009473:Neuronal Plasticity / Q000502:physiology*; D011712:Pyramidal Tracts / Q000166:cytology* / Q000502:physiology*; D013997:Time Factors; D014851:Wakefulness / Q000502:physiology*