We are investigating the neural mechanisms underlying the generation of behavior in simpler invertebrate "model" systems. Currently, we are studying the structure and function of neurons in the medicinal leech, Hirudo medicinalis and the hawkmoth, Manduca sexta. These preparations were chosen for study because individual neurons can be identified from animal to animal and followed through development.
Many of our research projects involve an examination of how neurons change during development to give rise to adult-specific behaviors. As Manduca develops from the larval to adult form, dramatic changes in its nervous system are observed. Some larval neurons (not needed by the adult) undergo developmentally programmed cell death, while others are retained and re-modeled; their morphology and synaptic contacts become altered. In addition, many new neurons are generated de novo and are used only in the adult stage. Our goals are to understand how all of these changes, which are under hormonal regulation, contribute to the "construction" of particular adult behaviors. We have focused on the re-use of larval interneurons and the cellular mechanisms that enable "old" neurons to be incorporated into the adult nervous system to generate new behaviors.
Our methods include: intra- and extracellular electrophysiological techniques, intracellular dye injection, laser scanning confocal microscopy, immunocytochemistry, and behavioral analysis.