Functional organization of adult motor cortex is dependent upon continued protein synthesis.
The functional organization of adult cerebral cortex is characterized by the presence of highly ordered sensory and motor maps. Despite their archetypical organization, the maps maintain the capacity to rapidly reorganize, suggesting that the neural circuitry underlying cortical representations is inherently plastic. Here we show that the circuitry supporting motor maps is dependent upon continued protein synthesis. Injections of two different protein synthesis inhibitors into adult rat forelimb motor cortex caused an immediate and enduring loss of movement representations. The disappearance of the motor map was accompanied by a significant reduction in synapse number, synapse size, and cortical field potentials and caused skilled forelimb movement impairments. Further, motor skill training led to a reappearance of movement representations. We propose that the circuitry of adult motor cortex is perpetually labile and requires continued protein synthesis in order to maintain its functional organization.
Kleim
Jeffrey A
JA
Canadian Centre for Behavioural Neuroscience, Department of Psychology and Neuroscience, University of Lethbridge, 4401 University Drive, Lethbridge, Alberta T1K 3M4, Canada. jeffrey.kleim@uleth.ca
Bruneau
Rochelle
R
Calder
Kevin
K
Pocock
David
D
VandenBerg
Penny M
PM
MacDonald
Erin
E
Monfils
Marie H
MH
Sutherland
Robert J
RJ
Nader
Karim
K
D000367:Age Factors; D000818:Animals; D019054:Evoked Potentials, Motor / Q000187:drug effects / Q000502:physiology*; D008297:Male; D009044:Motor Cortex / Q000187:drug effects / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D011597:Psychomotor Performance / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D020318:Rats, Long-Evans; D013569:Synapses / Q000187:drug effects / Q000378:metabolism
D009419:Nerve Tissue Proteins; D011500:Protein Synthesis Inhibitors