NSF Award
9208649
Identifying the way in which information is transferred from one nerve cell to another in the spinal cord is important to understanding how the spinal cord functions to produce normal motor behavior. Information conveyed by a neuron is encoded in the rate and pattern of action potentials, or "spikes" transmitted along its axon. While one neuron's average rate of firing has clear effects on the firing of other neurons that it contacts through chemical connections called synapses, there is little experimental evidence as to what details of firing pattern may be transmitted from one neuron to another, especially for synapses that have small individual effects. That evidence will be provided by the research to be done under this award to Drs. Timothy Cope and Brian Clark. The work will use the synapse of type Ia muscle spindle sensory neurons onto spinal motoneurons, which is part of the familiar stretch reflex circuitry. In addition, this work will yield important new information on how multiple sensory neurons interact when their firing becomes partially synchronized, a situation that appears to typify the action of stretch-sensitive sensory neurons during dynamic changes of muscular length. The results of this research will be significant in two ways: first, it will reveal what features of the spike trains of sensory neurons are actually important for the control of muscles and movements; and second, it will detail the influence between neurons that have a relatively weak synaptic connection, thus shedding light on the mode of information transfer across synapses. This basic research will contribute to understanding the way in which the central nervous controls movement.
