Dr. Lewis E. Deaton

My laboratory studies the physiology of freshwater, estuarine, and marine invertebrates. One current research project centers on the physiology and endocrinology of ion and water balance in brackish water invertebrates. This work involves studies of cellular volume regulation, epithelial permeability to water and ions, and hormones involved in salt and water balance. Another area of interest is the physiology and endocrinology of evisceration in holothuroid echinoderms. These animals expel their internal organs in response to a variety of noxious stimuli. The biological significance of this phenomenon is unclear, but it appears to be initiated by the secretion of a neurohormone. The goal of this particular project is the isolation and identification of the evisceration hormone. The physiology and pharmacology of invertebrate muscles is also an area of current research interest. The clam heart, like mammalian hearts, is myogenic. It is excited by both 5-hydroxytryptamine and the molluscan neuropeptide FMRFamide, but the chain of cellular events responsible for the excitation is unclear. Louisiana offers access to a wide variety of aquatic habitats, each with a unique, highly adapted fauna. The goal of this laboratory is to enhance our understanding of the physiological mechanisms necessary for existence in fresh water, the sea, and the zone where these two media mix.