title: Posterior parietal cortex contains a command apparatus for hand movements.
abstract: Mountcastle and colleagues proposed that the posterior parietal cortex contains a "command apparatus" for the operation of the hand in immediate extrapersonal space [Mountcastle et al. (1975)J Neurophysiol38(4):871-908]. Here we provide three lines of converging evidence that a lateral region within area 5 has corticospinal neurons that are directly linked to the control of hand movements. First, electrical stimulation in a lateral region of area 5 evokes finger and wrist movements. Second, corticospinal neurons in the same region of area 5 terminate at spinal locations that contain last-order interneurons that innervate hand motoneurons. Third, this lateral region of area 5 contains many neurons that make disynaptic connections with hand motoneurons. The disynaptic input to motoneurons from this portion of area 5 is as direct and prominent as that from any of the premotor areas in the frontal lobe. Thus, our results establish that a region within area 5 contains a motor area with corticospinal neurons that could function as a command apparatus for operation of the hand.
authors.affiliation: University of Pittsburgh Brain Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261.|Systems Neuroscience Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261.|Center for the Neural Basis of Cognition, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261.|Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261.
authors.forename: Jean-Alban
authors.initials: JA
authors.lastname: Rathelot
authors.affiliation: University of Pittsburgh Brain Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261.|Systems Neuroscience Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261.|Center for the Neural Basis of Cognition, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261.|Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261.
authors.forename: Richard P
authors.initials: RP
authors.lastname: Dum
authors.affiliation: University of Pittsburgh Brain Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261; strickp@pitt.edu.|Systems Neuroscience Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261.|Center for the Neural Basis of Cognition, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261.|Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261.
authors.forename: Peter L
authors.initials: PL
authors.lastname: Strick
mesh_terms: D000818:Animals; D004558:Electric Stimulation; D005260:Female; D005385:Fingers / Q000502:physiology*; D006225:Hand / Q000294:innervation*; D008253:Macaca mulatta; D008297:Male; D009046:Motor Neurons / Q000502:physiology*; D009068:Movement / Q000502:physiology*; D010296:Parietal Lobe / Q000502:physiology*
keywords: cerebral cortex; motor control; motor systems; movement control