| Lynne Fieber Director Neurophysiology Core Associate Professor of Marine Biology and Fisheries NIEHS-MFBSC Fax: 305-361-4600 Web Site http://www.rsmas.miami.edu Email:lfieber@rsmas.miami.edu
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B.S. (1979) Zoology, University of Michigan, Ann Arbor, MI
M.S. (1983) Marine Biology, RSMAS, University of Miami, Miami, FL
Ph. D. (1989) Pharmacology, University of Miami School of Medicine
Postdoc. (1990-91) Cell Biology & Anatomy, Washington Univ., St. Louis,
MO
Postdoc. (1992-94) Marine Biology, RSMAS, University of Miami, Miami, FL
My laboratory is devoted to studies of comparative physiology of single cells from the nervous systems of fish and invertebrates. In particular, I study the role of ion channels on cell membranes in cellular communication. The molecules that compose these ion channels are remarkably similar in eukaryotes, but they are combined in different ways to accomplish their function within the design of each animal's nervous system. Marine animals historically have served as good models of mammalian physiology in this regard. Although their nervous systems are less complex than those of higher vertebrates, this relative simplicity becomes an advantage when the aim is to elucidate basic mechanisms of nervous system function. Two applications of the technique used, called single cell voltage clamping, are illustrative of the work progressing in my laboratory.
One study involves certain cells in the nervous system of the marine opistobranch mollusc, Aplysia. During sexual maturation, these cells, called bag cell neurons, develop the capability of storing hormones that are released during periods of nervous system stimulation. The hormones are important to the process of egg laying, and so must not be released before the animal is sexually mature. The puzzle here is to understand how the ion channels on the bag cell membranes are regulated so that they are not stimulated to prematurely communicate the signal to release hormone to the bag cells.
Another study concerns glial cells associated with the peripheral nerves of a local tropical fish, the bicolor damselfish. This fish is naturally susceptible to a disease of the nervous system called damselfish neurofibromatosis. The disease causes tumors that are composed of masses of Schwann cells and other cells. We are trying to understand if a change in the ion channels for potassium ions on the Schwann cells is associated with the nervous system disturbance that causes the tumors.
An additional application of the technique is the study of how marine toxins
from dinoflagellates affect ion channels important to the function of the
nervous system of humans. This effort is aimed at an understanding how human
health is affected by huge aggregations of these animals in red tides, or
by the toxins becoming concentrated in consumed seafood.
Gerdes, R., and Fieber, L. A. 2006. Life history and aging of captive-reared California sea hares (Aplysia californica). J. Amer. Assn. Lab. An. Sci. 45:40-47.
Fieber, L. A., M. C. Schmale, N. Jordi, E. Orbesen, G. A. Diaz and T. R. Capo. 2005. Von Bertalanffy growth models for hatchery-reared A. californica. Bull. Mar. Sci. 76:95-104.
Fieber, L.A. 2003. Voltage-gated ion currents of Schwann cells in cell culture models of human neurofibromatosis. J. Exp. Zool. 300A:76-83.
Capo, T. R., L. A. Fieber, D. L. Stommes, and P. J. Walsh. 2003. Reproductive
output in the hatchery-reared California sea hare at different stocking densities.
Contemp. Topics Lab. An. Sci. 42:31-35.
Capo, T. R., L. A. Fieber, D. L. Stommes, and P. J. Walsh. (2002) The effect of stocking density on growth rate and maturation time in laboratory-reared California sea hares. Contemp. Topics Lab. An. Sci. 41:25-30.