Anticipatory activity in primary motor cortex codes memorized movement sequences

Neuron. 2005 Mar 24;45(6):967-73. doi: 10.1016/j.neuron.2005.01.036.


Movement sequences, defined both by the component movements and by the serial order in which they are produced, are fundamental building blocks of motor behavior. The serial order of sequence production is strongly encoded in medial motor areas. It is not known to what extent sequences are further elaborated or encoded in primary motor cortex. Here, we describe cells in the primary motor cortex of the monkey that show anticipatory activity exclusively related to a specific memorized sequence of upcoming movements. In addition, the injection of muscimol, a GABA agonist, into motor cortex resulted in an increase in the error rate during sequence production, without concomitant effects on nonsequenced motor performance. Our results challenge the role of medial motor areas in the control of well-practiced movement sequences and suggest that motor cortex contains a complete apparatus for the planning and production of this complex behavior.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Action Potentials / physiology*
  • Animals
  • Arm / innervation
  • Arm / physiology
  • GABA Agonists / pharmacology
  • Learning / physiology
  • Macaca mulatta
  • Male
  • Memory / physiology*
  • Motor Cortex / anatomy & histology
  • Motor Cortex / drug effects
  • Motor Cortex / physiology*
  • Movement / physiology*
  • Nerve Net / drug effects
  • Nerve Net / physiology
  • Neural Inhibition / drug effects
  • Neural Inhibition / physiology
  • Neural Pathways / drug effects
  • Neural Pathways / physiology
  • Neurons / drug effects
  • Neurons / physiology*
  • Psychomotor Performance / physiology*
  • Synaptic Transmission / drug effects
  • Synaptic Transmission / physiology
  • gamma-Aminobutyric Acid / metabolism


  • GABA Agonists
  • gamma-Aminobutyric Acid