CAIN, S.D.; WOODWARD, O.H.; Friday Harbor Labs, Univ of Washington; Friday Harbor Labs, Univ of Washington: The use of multiple transmitters controlling ciliary beating on the foot on the sea slug, Tritonia diomedea

The use of cilia in locomotion is limited to a few large, marine animals, most of which are nudibranchs. However, unlike muscular locomotion, the arrival of a single nerve impulse from a motoneuron does not correlate in any way to a given phase or beat frequency of the cilia on the epithelial cells driving ciliary locomotion. How then are behaviors such as turning, accelerating, and stopping coordinated by the central nervous system? The nudibranch mollusc Tritonia diomedea crawls using an extensive field of cilia covering the epithelium of its foot. T. diomedea is an important model for understanding orientation behavior related to water currents, olfactory signals, and magnetic fields. Therefore, understanding how the out put of central components controls the effectors cells is necessary to understand how these behavioral circuits work. Currently, we have identified four neurotransmitters (dopamine, 5HT, acetylcholine, and TPeps) that affect the ciliary transport rate of the foot epithelium or beat frequency of individual ciliated cells. Three transmitters stimulate ciliary beating, dopamine, 5HT, and TPeps. In contrast, acetylcholine decreases the beat frequency, but only on a subset of cells. Using immunohistochemistry, we have determined the distribution of the four transmitters within the foot and CNS. How these distributions relate to the control of ciliary beating observed in the transport studies will be discussed.