Lon A. Wilkens

Professor
Ph.D., - Florida State University

Phone: (314) 516-6222
Fax: (314) 516-6233

E-mail: lon_wilkens@umsl.edu

Sensory systems have evolved with specialized adaptations necessary for survival. In my laboratory, evolutionary adaptations in sensory function have been investigated in a variety of organisms. These include receptor physiology and escape behavior in bivalve molluscs (the scallop and giant clam Tridacna), vision and bioluminescence in polychaete annelids, mechanosensitivity in crustaceans (crayfish and lobsters) with emphasis on orientation and locomotory behaviors (e.g. feeding, escape, mating), and electroreception in the paddlefish.

The passive electrosense of the paddlefish is associated with the uniquely elongated rostrum of this fish and evolved relative to the ontogeny of planktivorous feeding. Current studies in my laboratory include: 1) video analysis of electrically-mediated feeding behavior in the paddlefish along with physiological/neuroanatomical analysis of the electrosensory system in the paddlefish brain and 2) dynamical sensory properties of crayfish tactile sensilla with respect to noise, and the mechanisms of sensory integration centrally that encode stimulus direction and velocity of hydrodynamic signals.

• 2010 Metzen, M., Chambwa, M., Wilkens, L.A. and Hofmann, M.H. Descending projections to the brain stem and spinal cord in the paddlefish Polyodon spathula. Brain Behav. Evol. 75:1-2 (doi:10.1159/000274979).
• 2009 Chagnaud, B.P., Wilkens, L.A. and Hofmann, M.H. Receptive field organization of electrosensory neurons in the paddlefish (Polyodon spathula). J. Physiol. (Paris). 102, 246-255. doi:10.1016/j.jphysparis.2008.10.006.
• Pothmann, L., Wilkens, L.A., Schweitzer, C. and Hofmann, M.H. Parallel pathways for electrosensory information from the dorsal octavolateralis nucleus to the midbrain in the paddlefish. Brain Res. 1265, 93-102. doi:10.1016/j.brainres.2009.02.007
• Hofmann, M.H., Chagnaud, B. and Wilkens, L.A. An edge detection filter improves spatial resolution in the electrosensory system of the paddlefish. J. Neurophysiol. 102, 797-804.
• 2008 Hofmann, M.H., Jung, N., Preissner, M., Siebenaller, U. and Wilkens, L.A. Response properties of electrosensory units in the midbrain tectum of the paddlefish (Polyodon spathula). J. Exp. Biol. 211, 773-779. doi:10.1242/jeb.009795
• Wilkens, L.A. and Hofmann, M.H. Electroreception. In: Senses on the Threshold, Function and Evolution of the Sense Organs in Secondarily Aquatic Vertebrates. (eds. H.G. Thewissen and Nummela).Univ. California Press, pp. 325-332.
• Hofmann, M.H. and Wilkens, L.A. Magnetoreception. In: Senses on the Threshold, Function and Evolution of the Sense Organs in Secondarily Aquatic Vertebrates, (eds. H.G. Thewissen, S. Nummela). University of California Press, pp. 317-324.
• Wilkens, L.A. and Moss, F. Mechanoreceptors and Stochastic Resonance. Scholarpedia 3, 1635.
• Wilkens, L.A. Primary inhibition by light: A unique property of bivalve photoreceptors. American Malacological Bulletin 26, 101-109.
• 2007 Wilkens, L.A. and Hofmann, M.H. The paddlefish rostrum as an electrosensory organ: a novel adaptation for plankton feeding. Bioscience 57, 399-407.
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• 006 Wilkens, L.A. Neurobiology and behavior of the scallop. In Scallops: Biology, Ecology and Aquaculture, Second Edition. N. Shumway and G.J. Parson eds., Elsevier Science Publ., Amsterdam, pp. 317-356.
• 2005 Wilkens, L.A. and Hofmann, M.H. Behavior of animals with passive, low-frequency electrosensory systems. In: Electroreception, (eds. T.H. Bullock, C. Hopkins). Springer Handbook of Auditory Research (Series eds. R.R. Fay, A.N. Popper). Springer-Verlag, New York, pp. 229-263.
• Hofmann, M.H., Falk, J. and Wilkens, L.A. (2004). Passive electroreception: sensing electric fields through time and space. Fluctuations and Noise Letters (In press)
• Wilkens, L.A. and Hofmann, M.H. (2004). Behavior of animals with passive, low-frequency electrosensory systems. In: Electroreception, (eds. T.H. Bullock, C. Hopkins). Springer Handbook of Auditory Research (Series eds. R.R. Fay, A.N. Popper). Springer-Verlag, New York, pp. (In press)
• Wilkens, L.A. (2003). Adaptation of the rostral ampullary electrosense for plankton feeding by the paddlefish. In: The Senses of Fishes: Adaptations for the Reception of Natural Stimuli, (eds. G. von der Emde, J. Mogdans, B.G. Kapoor). Narosa Publishing House, New Dehli, pp. 288-307.
• Pettigrew, J. D. and Wilkens, L. (2003). Paddlefish and Platypus: Parallel evolution of passive electroreception in a rostral bill organ. In: Sensory Processing in Aquatic Environments, (eds. S.P. Collin, N.J. Marshall). Springer-Verlag, New York, pp. 420-433.
• Wilkens, L.A., Hofmann, M., and Wojtenek, W. (2003). The electric sense of the paddlefish: a passive system for the detection and capture of zooplankton prey. J. Physiol. Paris 96, 363-377.
• Bahar, S., Neiman, A., Wilkens, L.A. and Moss, F. (2002). Phase Synchronization and stochastic resonance effects in the crayfish caudal photoreceptor. Phys. Rev. E. 65, 050901.
• Hofmann, M.H., Wojtenek, W. and Wilkens, L.A. (2002). Central organization of the electrosensory system in the paddlefish (Polyodon spathula). J. Comp. Neurol. 446, 25-36.
• Wilkens, L.A. (2001). Tuning in to paddlefish. Missouri Conservationist 62, 14-18. http://mdc.mo.gov/conmag/2001/01/tuning-paddlefish
• Wilkens, L.A., Wettring, B.A., Wagner, E., Wojtenek, W., and Russell, D.F (2001). Prey detection in selective plankton feeding by the paddlefish: Is the electric sense sufficient. J. Exp. Biol. 204, 1381-1389.
• Wojtenek, W., Pei, X. and Wilkens, L.A. (2001). Paddlefish strike at artificial dipoles simulating the weak electric fields of planktonic prey. J. Exp. Biol. 204, 1391-1399.
• Wojtenek, W., Hofmann, M.H. and Wilkens, L.A. (2001). Primary afferent electrosensory neurons represent paddlefish natural prey. Neurocomputing 38, 451-458.
• Gurgens, C., Russell, D.F. and Wilkens, L.A. (2000). Avoidance of metallic obstacles by the paddlefish Polyodon spathula due to electrosense. J. Fish Biology. 57, 277-290.
• Russell, D.F., Wilkens, L.A. and Moss, F. 1999. Use of behavioural stochastic resonance by paddlefish for feeding. Nature. 402: 291-294.
• Douglass, J.K. and Wilkens, L.A. 1998. Directional selectivities of near-field filiform mechanoreceptors on the crayfish tailfan (Crustacea: Decapoda). J. Comp. Physiol. A 183:23-34.
• Wilkens, L.A., Russell, D.F., Pei, X. And Gurgens, C. 1997. The paddlefish rostrum functions as an electrosensory antenna in plankton feeding. Proc. Roy Soc. Lond. B 254:1723-1729.
• Wilkens, L.A., Schmitz, B. and Herrnkind, W.F. 1996. Antennal responses to hydrodynamic and tactile stimuli in the spiny lobster, Panulirius argus. Biological Bulletin 191:187-198.
• Pei, X., Moss, F., and Wilkens, L. 1996. Light enhanced hydrodynamic signaling in the candal photoreception interneuron of the crayfish. J. Neurophysiol 76:3002-3011.
• Wilkens, L.A. and Douglass, J.K. 1994. A paradigm for analysis of near-field hydrodynamic sensitivity in crustaceans. J. Exp. Biol. 189:263-272.
• Douglass, J.K., Wilkens, L.A. , Pantazelou, E., and Moss, F. 1993. Noise enhancement of information transfer in crayfish mechanoreceptors by stochastic resonance. Nature 365:337-340.

Wilkens CV