title: Dynamic reorganization of neural activity in motor cortex during new sequence production.
abstract: Although previous studies have shown that primary motor cortex (M1) neurons are modulated during the performance of a sequence of movements, it is not known how this neural activity in the M1 reorganizes during new learning of sequence-dependent motor skills. Here we trained monkeys to move to each of four spatial targets to produce multiple distinct sequences of movements in which the spatial organization of the targets determined uniquely the serial order of the movements. After the monkeys memorized the sequences, we changed one element of these over-practised sequences and the subjects were required to learn the new sequence through trial and error. When one element in an over-learned four-element sequence was changed, the sequence-specific neural activity was totally disrupted, but relatively minor changes in the direction-specific activity were observed. The data suggest that sequential motor skills are represented within M1 in the context of the complete sequential behavior rather than as a series of single consecutive movements; and sequence-specific neurons in the M1 are involved in new learning of sequence by using memorized knowledge to acquire complex motor skill efficiently.
authors.affiliation: Department of Neurology, University of Minnesota, Minneapolis, MN, 55414, USA.|Brain Science Center, Veterans Administration Medical Center, Minneapolis, MN, USA.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Lu
authors.affiliation: Department of Neuroscience and Neurology, University of Minnesota, Minneapolis, MN, USA.|Neurology Service, Veterans Administration Medical Center, Minneapolis, MN, USA.
authors.forename: James
authors.initials: J
authors.lastname: Ashe
mesh_terms: D000200:Action Potentials; D000818:Animals; D007858:Learning / Q000502:physiology*; D008253:Macaca mulatta; D008297:Male; D008568:Memory / Q000502:physiology*; D008839:Microelectrodes; D009044:Motor Cortex / Q000502:physiology*; D009048:Motor Skills / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology; D009473:Neuronal Plasticity / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D009483:Neuropsychological Tests; D010775:Photic Stimulation; D014796:Visual Perception / Q000502:physiology
keywords: hand movement; monkey; neural activity; plasticity; procedural learning