title: Dissociating movement from movement timing in the rat primary motor cortex.
abstract: Neural encoding of the passage of time to produce temporally precise movements remains an open question. Neurons in several brain regions across different experimental contexts encode estimates of temporal intervals by scaling their activity in proportion to the interval duration. In motor cortex the degree to which this scaled activity relies upon afferent feedback and is guided by motor output remains unclear. Using a neural reward paradigm to dissociate neural activity from motor output before and after complete spinal transection, we show that temporally scaled activity occurs in the rat hindlimb motor cortex in the absence of motor output and after transection. Context-dependent changes in the encoding are plastic, reversible, and re-established following injury. Therefore, in the absence of motor output and despite a loss of afferent feedback, thought necessary for timed movements, the rat motor cortex displays scaled activity during a broad range of temporally demanding tasks similar to that identified in other brain regions.
authors.affiliation: Drexel University School of Biomedical Engineering and Health Sciences and.
authors.forename: Eric B
authors.initials: EB
authors.lastname: Knudsen
authors.affiliation: Drexel University School of Biomedical Engineering and Health Sciences and.
authors.forename: Marissa E
authors.initials: ME
authors.lastname: Powers
authors.affiliation: Drexel University School of Biomedical Engineering and Health Sciences and Drexel University College of Medicine Departments of Neurobiology and Anatomy, Philadelphia, Pennsylvania 19104 karen.moxon@drexel.edu.
authors.forename: Karen A
authors.initials: KA
authors.lastname: Moxon
mesh_terms: D000818:Animals; D003655:Decerebrate State / Q000503:physiopathology; D004576:Electromyography; D006614:Hindlimb / Q000294:innervation / Q000502:physiology; D008297:Male; D009044:Motor Cortex / Q000502:physiology*; D009068:Movement / Q000502:physiology*; D009474:Neurons / Q000502:physiology; D051381:Rats; D020318:Rats, Long-Evans; D012201:Reward; D013239:Stereotyped Behavior / Q000502:physiology
keywords: brain machine interface; motor cortex; rat; spinal cord injury; temporal scaling