Skilled-learning-induced potentiation in rat sensorimotor cortex: a transient form of behavioural long-term potentiation.
The relation between the acquisition of a skilled motor task and synaptic plasticity in the sensorimotor cortex of the awake, freely behaving rat was examined. Skilled-motor training was previously found to induce a functional reorganization of the caudal forelimb area, and to induce an increase in synaptic efficacy, measured in vitro, on the side contralateral to the reaching forelimb. Here, we repeatedly measured neocortical evoked potential recordings in awake, freely behaving rats to examine whether skilled training would induce changes in polysynaptic efficacy on the side contralateral to the reaching forelimb. We found that the increase in task proficiency, but not the acquisition of task requirements or the maintenance of task proficiency, induced an increase in synaptic efficacy on the side contralateral to the reaching forelimb. We also tested the hypothesis that skilled learning induced potentiation shares similar mechanisms to long-term potentiation (LTP) and long-term depression by artificially manipulating polysynaptic efficacy in skilled rats with high- and low-frequency stimulation. We observed that, compared with the ipsilateral side, less potentiation but more depression could be induced on the side contralateral to the reaching forelimb. We conclude that a transient, network-based LTP-like mechanism operates during the learning of a skilled motor task.
Monfils
M-H
MH
Behavioural Neuroscience Research Group, Department of Psychology, University of Calgary, 2500 University Drive Northwest, Calgary, Alberta, Canada T2N 1N4.
Teskey
G C
GC
D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D004307:Dose-Response Relationship, Radiation; D004558:Electric Stimulation / Q000379:methods; D004567:Electrodes, Implanted; D019054:Evoked Potentials, Motor / Q000502:physiology / Q000528:radiation effects; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology / Q000528:radiation effects; D007839:Functional Laterality / Q000502:physiology / Q000528:radiation effects; D007858:Learning / Q000502:physiology*; D017774:Long-Term Potentiation / Q000502:physiology*; D036881:Long-Term Synaptic Depression / Q000502:physiology; D008297:Male; D009044:Motor Cortex / Q000502:physiology* / Q000528:radiation effects; D009048:Motor Skills / Q000502:physiology* / Q000528:radiation effects; D051381:Rats; D020318:Rats, Long-Evans; D013003:Somatosensory Cortex / Q000502:physiology* / Q000528:radiation effects; D013997:Time Factors