Functional switch between motor tracts in the presence of the mAb IN-1 in the adult rat.
Fine finger and hand movements in humans, monkeys, and rats are under the direct control of the corticospinal tract (CST). CST lesions lead to severe, long-term deficits of precision movements. We transected completely both CSTs in adult rats and treated the animals for 2 weeks with an antibody that neutralized the central nervous system neurite growth inhibitory protein Nogo-A (mAb IN-1). Anatomical studies of the rubrospinal tracts showed that the number of collaterals innervating the cervical spinal cord doubled in the mAb IN-1- but not in the control antibody-treated animals. Precision movements of the forelimb and fingers were severely impaired in the controls, but almost completely recovered in the mAb IN-1-treated rats. Low threshold microstimulation of the motor cortex induced a rapid forelimb electromyography response that was mediated by the red nucleus in the mAb IN-1 animals but not in the controls. These findings demonstrate an unexpectedly high capacity of the adult central nervous system motor system to sprout and reorganize in a targeted and functionally meaningful way.
Raineteau
O
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Brain Research Institute, University and Swiss Federal Institute of Technology (ETH) Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland. rainet@hifo.unizh.ch
Fouad
K
K
Noth
P
P
Thallmair
M
M
Schwab
M E
ME
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D001522:Behavior, Animal; D005260:Female; D008297:Male; D009044:Motor Cortex / Q000502:physiology*; D009185:Myelin Proteins / Q000037:antagonists & inhibitors / Q000502:physiology*; D000070798:Nogo Proteins; D051381:Rats; D011917:Rats, Inbred Lew; D012012:Red Nucleus / Q000502:physiology*
D000911:Antibodies, Monoclonal; D009185:Myelin Proteins; D000070798:Nogo Proteins; C000603199:RTN4 protein, human; C000603197:Rtn4 protein, rat