Combining modules for movement.
We review experiments supporting the hypothesis that the vertebrate motor system produces movements by combining a small number of units of motor output. Using a variety of approaches such as microstimulation of the spinal cord, NMDA iontophoresis, and an examination of natural behaviors in intact and deafferented animals we have provided evidence for a modular organization of the spinal cord. A module is a functional unit in the spinal cord that generates a specific motor output by imposing a specific pattern of muscle activation. Such an organization might help to simplify the production of movements by reducing the degrees of freedom that need to be specified.
Bizzi
E
E
Department of Brain and Cognitive Sciences and McGovern Institute for Brain Research, Massachusetts Institute of Technolgy 46-6189, 77 Massachusetts Avenue, Cambridge, MA 02139, USA. ebizzi@mit.edu
Cheung
V C K
VC
d'Avella
A
A
Saltiel
P
P
Tresch
M
M
D000818:Animals; D001001:Anura; D009068:Movement / Q000502:physiology*; D009121:Muscle Denervation; D018482:Muscle, Skeletal / Q000294:innervation / Q000502:physiology; D009434:Neural Pathways / Q000502:physiology*; D013116:Spinal Cord / Q000166:cytology / Q000502:physiology*; D014714:Vertebrates / Q000502:physiology