Two distinct layer-specific dynamics of cortical ensembles during learning of a motor task

Nat Neurosci. 2014 Jul;17(7):987-94. doi: 10.1038/nn.3739. Epub 2014 Jun 1.


The primary motor cortex (M1) possesses two intermediate layers upstream of the motor-output layer: layer 2/3 (L2/3) and layer 5a (L5a). Although repetitive training often improves motor performance and movement coding by M1 neuronal ensembles, it is unclear how neuronal activities in L2/3 and L5a are reorganized during motor task learning. We conducted two-photon calcium imaging in mouse M1 during 14 training sessions of a self-initiated lever-pull task. In L2/3, the accuracy of neuronal ensemble prediction of lever trajectory remained unchanged globally, with a subset of individual neurons retaining high prediction accuracy throughout the training period. However, in L5a, the ensemble prediction accuracy steadily improved, and one-third of neurons, including subcortical projection neurons, evolved to contribute substantially to ensemble prediction in the late stage of learning. The L2/3 network may represent coordination of signals from other areas throughout learning, whereas L5a may participate in the evolving network representing well-learned movements.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Conditioning, Operant
  • Cyclic Nucleotide Phosphodiesterases, Type 5 / genetics
  • Dependovirus / genetics
  • Efferent Pathways / physiology
  • Forelimb / innervation
  • Forelimb / physiology
  • Genetic Vectors
  • Image Processing, Computer-Assisted
  • Learning / physiology*
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Motor Cortex / physiology*
  • Motor Neurons / physiology
  • Motor Skills*
  • Neuroimaging
  • Neurons / physiology
  • Patch-Clamp Techniques
  • Psychomotor Performance
  • Reward


  • Cyclic Nucleotide Phosphodiesterases, Type 5