Proposal: IBN 98-17905 PI: Andrew D. McClellan Neuronal Basis of Turning Maneuvers: An adaptive Variation of Locomotion Behavioral functions that are repetitive in nature are usually referred to as rhythmic motor acts, such as locomotion (walking, swimming, or flying), respiration, heart rate, mating, chewing, and digestion. Rhythmic motor acts usually are generated by sets of nerve cells (neurons) that are called neuronal oscillators. The neuronal oscillators that generate rhythmic motor acts often are continually modified to adapt them to the ongoing needs of an animal. For example, locomotion often displays a number of basic but critically important adaptive variations, including acceleration, deceleration, turning, equilibrium adjustments, and steering. In the present project, Dr. Andrew McClellan will continue his work on how the lamprey brain modulates neuronal oscillators in the spinal cord to produced turning maneuvers, a very important adaptive variation of locomotor behavior (i.e. swimming). The lamprey has a number of very powerful technical advantages that make it an excellent model system in which to study the neural systems in the brain that initiate turning behavior. In particular, anatomical experiments will be used to map the locations of neurons in the neural systems in the brain that mediate turning behavior. In addition, in order to determine how these systems operate, several types of neurophysiological experiments will be performed: intracellular recordings to determine the activity patterns in individual brain neurons during turning motor activity; neuronal blocking experiments to test the contributions of various populations of brain neurons to turning; and lesion experiments to test hypotheses about the neuronal pathways in the brain that mediate turning. The results from this project will contribute to our understanding of how nerve cells in the lamprey brain produce turning and also may add fundamental information concerning adaptive variations of rhythmic behaviors in other animals.
