LAY ABSTRACT Selection and Generation of Rhythmic Motor Patterns by the Spinal Cord IBN-9807991 Animals, including human beings, are constantly making behavioral choices. Some of these behavioral choices may involve conscious deliberation, but others occur automatically. In vertebrate animals, the spinal cord mediates limb movements. In some cases, the spinal cord can select an appropriate limb movement for each of several situations, even in the absence of inputs from the brain. The turtle spinal cord, in particular, can appropriately select and generate several types of hindlimb movements on its own. This makes the turtle spinal cord an excellent "model system" to investigate how "circuits" of nerve cells can produce an appropriate behavior in vertebrates. The research performed under this NSF grant will address the general question, Does the selection and generation of movements depend mainly on the activity of individual nerve cells that are specialized for one type of movement or instead depend mainly on the activity of an interacting network of nerve cells, each of which contributes to multiple types of movements? This research will also test specific hypotheses about how the nerve cells in the turtle spinal cord are connected to one another to select and generate three types of a behavior termed "scratching," as well as two types of swimming. This research will contribute to our understanding of mechanisms of behavioral choice in vertebrates and to our understanding of the spinal cord control of limb movements. In addition, this research will provide training to graduate students in the design and execution of experiments involving neurophysiology and neuroanatomy.
