Modulation of use-dependent plasticity by d-amphetamine.
Use-dependent plasticity, thought to contribute to functional recovery after brain injury, is elicited by motor training. The purpose of this study was to determine if administration of d-amphetamine facilitates the effects of motor training on use-dependent plasticity. Healthy human volunteers underwent a training period of voluntary thumb movements under the effects of placebo or d-amphetamine in different sessions in a randomized double-blind, counterbalanced design. Previous work in a drug-naive condition showed that such training causes changes in the direction of thumb movements evoked by transcranial magnetic stimulation and in transcranial magnetic stimulation-evoked electromyographic responses. The endpoint measure of the study was the magnitude of training-induced changes in transcranial magnetic stimulation-evoked kinematic and electromyographic responses in the d-amphetamine and in the placebo conditions. Motor training resulted in increased magnitude, faster development and longer lasting duration of use-dependent plasticity under d-amphetamine compared to the placebo session. These results document a facilitatory effect of d-amphetamine on use-dependent plasticity, a possible mechanism mediating the beneficial effect of this drug on functional recovery after cortical lesions.
Bütefisch
Cathrin M
CM
Human Cortical Physiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892-1430, USA.
Davis
Benjamin C
BC
Sawaki
Lumy
L
Waldvogel
Daniel
D
Classen
Joseph
J
Kopylev
Leonid
L
Cohen
Leonardo G
LG
D000328:Adult; D001930:Brain Injuries / Q000188:drug therapy; D000697:Central Nervous System Stimulants / Q000008:administration & dosage*; D003213:Conditioning, Psychological / Q000187:drug effects; D003913:Dextroamphetamine / Q000008:administration & dosage*; D004311:Double-Blind Method; D004558:Electric Stimulation; D019054:Evoked Potentials, Motor / Q000502:physiology; D005260:Female; D006801:Humans; D008280:Magnetics; D008297:Male; D009068:Movement / Q000502:physiology; D009473:Neuronal Plasticity / Q000187:drug effects*; D013933:Thumb / Q000502:physiology
D000697:Central Nervous System Stimulants; D003913:Dextroamphetamine