Steve I. Perlmutter

perl@u.washington.edu
Research Associate Professor, Department of Physiology & Biophysics; Research Affiliate, Washington National Primate Research Center

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Primates generate an incredibly varied repertoire of motor behaviors. We are interested in neural processes in the spinal cord and cerebral cortex that accomplish this flexibility for skillful voluntary movements of the arm and hand.

Information about the intended goal of a movement must be transformed into a spatial and temporal pattern of muscle activity to achieve a desired behavior. Neural pathways execute this transformation by integrating signals specifying behavioral intent, the state of the musculoskeletal system, and external constraints and loads. This process is dynamic and eminently plastic - the motor system has a rich capacity to adapt to changing task requirements, environmental conditions, and even internal damage. We are studying how the brain and spinal cord achieve this transformation.

Our work is relevant to clinical issues of motor impairment and recovery of function following central nervous system damage. Abnormal patterns of muscle activation following brain and spinal cord injury contribute to weakness and loss of coordination. We still do not understand the neural mechanisms of motor deficit and of natural or therapy-induced restoration of function following central lesions. Our research will advance our understanding of the capacity for adaptation, and suggest ways to exploit this potential for improved function.

Neurophysiological, anatomical, behavioral and computational techniques are employed in the laboratory. We record the activity of individual neurons, pairs of neurons, and local field potentials in behaving macaque monkeys during performance of different motor behaviors. Neuron recordings are done in conjunction with stimulation and correlational techniques to identify inputs and outputs, and with local iontophoresis to characterize specific neurotransmitter and neuromodulatory systems. Neuroanatomical experiments trace neural projections, and neural network models explore the computational properties of neural circuits. Together, these techniques allow us to elucidate the organization and function of the cortical and spinal circuitry that controls movement.