Speaker: Peter L. Strick, Ph.D., University of Pittsburgh and Pittsburgh VA Medical Center
Chair: Sonja Kotz, University of Manchester, UK and Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany

Thursday, October 15, 3:00 – 4:00 pm, Grand Ballroom

Peter L. Strick, Ph.D. is the Scientific Director of the University of Pittsburgh Brain Institute, Thomas Detre Professor and Chair of the Department of Neurobiology at the University of Pittsburgh, and a Senior Research Career Scientist at the Pittsburgh VA Medical Center. He received his B.A. in Biology and his Ph.D. in Anatomy from the University of Pennsylvania. Professor Strick’s many awards include the C.J. Herrick Award from the American Association of Anatomists, a Javits Neuroscience Investigator Award from the NIH-NINDS, the Established Investigator Award from the National Alliance for Research on Schizophrenia and Depression, the President’s Award for Excellence and Leadership in Research from SUNY-Upstate Medical Center, the Chancellor’s Distinguished Research Award, and University Distinguished Professor of Neurobiology. He was also elected to the American Academy of Arts and Sciences and to the National Academy of Sciences.

Professor Strick’s research focuses on four major areas: the generation and control of voluntary movement by the motor areas of the cerebral cortex; the motor and cognitive functions of the basal ganglia and cerebellum; the neural basis for the mind-body connection; and unraveling the complex neural networks that comprise the central nervous system.

A Tale of Two Primary Motor Areas: “Old” and “New” M1

This presentation will lay out the evidence to develop the following thesis:

1) The central control of movement is faced with an evolutionary constraint: Our skeletomotor system is built on the framework of a relatively ancient spinal cord.
2) Most descending systems, including the corticospinal system, use the pattern generators and motor primitives that are built into the spinal cord to generate motor output.
3) Cortico motoneuronal (CM) cells (i.e., cortical neurons with axons that make monosynaptic connections with motoneurons) are a relatively new phylogenetic and ontogenetic development. Furthermore, CM cells are located in a separate part of the primary motor cortex.
4) Thus, area 4 is split into 2 regions: a rostral region we have termed “Old M1” which has disynaptic input to motoneurons; and a caudal region we have termed “New M1” which has monosynaptic input to motoneurons.

In essence, Old M1 makes use of the circuits built into the spinal cord to generate motor output. This region of the motor cortex enables the motor system to avoid the “curse of dimensionality” and to solve the “degrees of freedom problem.” In contrast, New M1 uses CM cells to bypass the constraints of spinal cord mechanisms. This region of the motor cortex enables the motor system to use all of the available degrees of freedom to sculpt novel patterns of motor output.

These arguments lead us to predict that the two regions of the motor cortex are differentially involved in motor learning.   We speculate that Old M1 is especially important during the initial stages of learning a new skill by enabling the motor cortex to use existing spinal circuits to rapidly construct new movement patterns. In contrast, New M1 may be especially important during the later stages of learning a new skill by enabling the motor cortex to refine and precisely specify patterns of motor output.