Abstract: DESCRIPTION (provided by applicant): The long term goal of this research is to contribute to the understanding of the sensory control of movement through studies of the cerebral cortex of macaques using physiological and behavioral methods. Emphasis will be placed on the role of primary motor, premotor, and parietal cortex in the control of limb, hand, and head movements. One major aim is to continue current research on the hypothesis that these areas represent movement by means of a stored set of behaviorally useful postures. A second aim is to study how these brain areas adapt as a function of practice with previously atypical movements. A third goal is to continue research on the hypothesis that restricted regions in motor and parietal cortex coordinate movements that defend the body from nearby threatening objects. These experiments will involve electrical stimulation of cortex using low currents (microamps); recording the activity of single neurons in cortex during movement; injection of muscimol, a chemical that temporarily deactivates a small region of cortex; and measuring behavior and muscle activity. This research should contribute to the diagnosis and treatment of disorders of sensory-motor function caused by developmental abnormalities, disease, trauma, aging, and unusual environments such as submersion in water or in outer space. The proposed research may also contribute to the development of limb prosthetics and artificial devices for object manipulation.

Public Health Relevance:
This Public Health Relevance is not available.

Thesaurus Terms:
body movement, cerebral cortex, psychomotor function, sensorimotor system, sensory neuropathy
brain electrical activity, direct cortical response, motor cortex, muscle function, parietal lobe /cortex, sensory signal detection
Macaca, behavior test, behavioral /social science research tag, brain electronic stimulator, electroencephalography, electromyography, electrostimulus, microelectrode, neuropsychological test, single cell analysis

Institution: PRINCETON UNIVERSITY
OFFICE OF RESEARCH AND PROJECT ADMINISTRATION
PRINCETON, NJ 085440036
Fiscal Year: 2006
Department: PSYCHOLOGY
Project Start: 01-APR-2004
Project End: 31-MAR-2009
ICD: NATIONAL INSTITUTE OF NEUROLOGICAL DISORDERS AND STROKE
IRG: SMI

The Journal of Neuroscience, March 14, 2007, 27(11):2760-2780

Behavioral/Systems/Cognitive
Relationship between Unconstrained Arm Movements and Single-Neuron Firing in the Macaque Motor Cortex

Tyson N. Aflalo and Michael S. A. Graziano
 
Department of Psychology, Princeton University, Princeton, New Jersey 08544-1010

All procedures were approved by the Princeton University Institutional Animal Care and Use Committee and the attendant veterinarian and were in accordance with National Institutes of Health and United States Department of Agriculture guidelines. We studied the motor cortex in the left hemispheres of two adult male Macaca fascicularis.

Surgery. For each monkey, an initial surgical operation was performed under isoflurane anesthesia and strict aseptic conditions, during which an acrylic skullcap was fixed to the skull with bone screws. A steel bolt for holding the head and a 2.5 cm diameter steel chamber for neuronal recording were also imbedded in the acrylic. The recording chamber was positioned for a vertical (dorsoventral) approach to the precentral gyrus. Each animal recovered from the surgery within 1 week but was given 2 additional weeks to allow the skull to grow tightly around the skull screws. In a subsequent procedure, also under deep anesthesia and aseptic conditions, the recording chamber was opened and a hole 10 mm in diameter was drilled through the layer of acrylic and the bone, exposing the dura.
Neuronal recording. During the daily recording sessions, the monkey sat in a Lexan primate chair with the head restrained by the head bolt. A hydraulic microdrive (Narishige, Tokyo, Japan) was mounted to the top of the recording chamber. A steel guide tube (a 22 gauge syringe needle) was lowered through the hole in the skull and into the granulation tissue that lay over the dura. Then the varnish-coated tungsten microelectrode (impedance of 0.5–2 M ; Frederick Haer Company, Bowdoinham, ME) was advanced from the guide tube through the dura and into the brain. Neural signals were amplified (model 1800 amplifier; A-M Systems, Carlsborg, WA), filtered (300–5000 Hz), and recorded at 25,000 Hz. An off-line spike-sorting algorithm was used to assign spikes to individual neurons. Typically one to three neurons could be reliably isolated on the electrode at one time.