Motor Learning Consolidates Arc-Expressing Neuronal Ensembles in Secondary Motor Cortex

Neuron. 2015 Jun 17;86(6):1385-92. doi: 10.1016/j.neuron.2015.05.022. Epub 2015 Jun 4.


Motor behaviors recruit task-specific neuronal ensembles in motor cortices, which are consolidated over subsequent learning. However, little is known about the molecules that can identify the participating neurons and predict the outcomes of the consolidation process. Using a mouse rotarod-learning task, we showed that lesion or inactivation of the secondary motor (M2) cortex disrupts learning of skilled movements. We tracked the endogenous promoter activity of the neuronal activity-regulated gene Arc in individual M2 neurons during rotarod learning by in vivo two-photon imaging of a knockin reporter. We found that task training initially recruits Arc-promoter-activated neurons and then consolidates them into a specific ensemble exhibiting persistent reactivation of Arc-promoter. The intensity of a neuron's initial Arc-promoter activation predicts its reactivation probability and neurons with weak initial Arc-promoter activation are dismissed from the ensemble during subsequent training. Our findings demonstrate a task-specific Arc-dependent cellular consolidation process in M2 cortex during motor learning.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, N.I.H., Intramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analysis of Variance
  • Animals
  • Cytoskeletal Proteins / genetics
  • Cytoskeletal Proteins / metabolism*
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • Learning / physiology*
  • Mice
  • Mice, Transgenic
  • Motor Activity / physiology*
  • Motor Cortex / cytology*
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism*
  • Neurons / metabolism*
  • Rotarod Performance Test
  • Time Factors


  • Cytoskeletal Proteins
  • Nerve Tissue Proteins
  • activity regulated cytoskeletal-associated protein
  • Green Fluorescent Proteins