Role of Presynaptic Mechanisms in the Control of Locomotion
The mechanisms underlying rhythmic behaviors such as walking, talking, and breathing will be studied. These are vital activities controlled by processing systems within the central nervous system. For locomotion (walking) the circuits are within the spinal cord. These circuits, called central pattern generators, create the oscillating signals that extend and flex the legs in patterns needed for walking. The process of generating rhythmical output is found in most multicellular animals, from terrestrial vertebrates to the simplest nematode worm. Behaviors are created by the sum of activity of connections between nerve cells (neurons), the properties of the neurons and the properties of their connections with other neurons (synapses). Mechanisms that affect the strength and timing of activity at synapses modulate the processes by which the brain distributes information and learns. The means by which the nervous system controls information flow across synapses will be studied to understand how that control is used to generate locomotion. The lamprey fish will be used because the circuitry responsible for creating locomotor patterns is accessible. Sophisticated imaging and electronic recording techniques will be applied to synapses within an intact and behaviorally relevant spinal cord. The work has implications affecting a wide range of fields. Understanding the means by which information flow is controlled at the synapse is the foundation of understanding many behaviors. At the level of locomotion improving comprehension of the underlying biological systems will improve understanding of problems as wide ranging as robot design to alleviating problems associated with spinal cord injury.