the central nervous system; motor neurons to coordinate muscle tensions; and sensory receptors that modify and adapt the central neuronal pattern to the specific structure of the animal and to its environment. We study the relatively simple movements (swimming) of one favorable invertebrate, the medicinal leech. Currently we are investigating 1) mechanisms by which brief sensory input evokes prolonged behavioral motor patterns and 2) the roles of sensory input in shaping neuronal activity patterns to generate effective locomotion. In addition, we are continuing to develop NeuroDynamix II , a graphical suite of computer models, to simulate dynamic properties of complex neuronal circuits, therewith to explore the behavioral implications of identified neuronal circuits and to investigate conceptual models. Our primary techniques include electrophysiological recording from identified neurons, pharma-cological manipulations, and computer modeling.

For more information about research interests, see my lab website.

Fan RJ, Friesen WO (2006) Characterization of central axon terminals of putative stretch receptors in leeches. J Comp Neurol 494:290-302.

Zheng M, Friesen WO, Iwasaki T (2007) Systems-level modeling of neuronal circuits for leech swimming. J Comput Neurosci 22:21-38.

Tian J, Iwasaki T, Friesen WO. (2007) Muscle function in animal movement: Passive mechanical properties of leech muscle . J Comp Physiol A 193:1205-1219.