Invertebrate Neurotransmitters

I have a long-standing interest in the identification and function of novel invertebrate neurotransmitters. My interests began with the study of mollucan FMRFamide neuropeptides and have continued with the identification of new insect neuropeptides. Most recently, students in my laboratory have discovered that nitric oxide may interact with octopamine to form novel bioactive compounds. We still have many regarding the synthesis and actions of these novel chemical messengers.

Publications and Presentations

Lehman, H. K. Greenberg, M. J., and Price, D. A. The FMRFamide-like peptide of Aplysia is FMRFamide. Biological Bulletin 167:460-466, 1984.

Lehman, H. K. and Greenberg, M. J. The actions of FMRFamide-like peptides on visceral and somatic muscles of the snail Helix aspersa. Journal of Experimental Biology 131:55-68, 1987.

Lehman, H.K., Murgiuc, C.M*, Miller, T., Lee, T.D. and J.G. Hildebrand. Crustacean cardioactive peptide in the sphinx moth, Manduca sexta. Peptides 14: 735-741, 1993.

Byrne, L*, Rosenstein, I., Kinnel, R., and Lehman, H.K. Novel neurotransmitters from octopaminergic neurons. 32th annual meeting of the Society for Neuroscience, Orlando, FL, 2002

Stoos, M*. and Lehman, H.K. The actions of nitrosylated octopamine compounds. 33th annual meeting of the Society for Neuroscience, San Diego, CA, 2004.

 

Octopaminergic Neurons

Neurotransmitters are vital elements of chemical transmission in the nervous system. Thus, the proper maintenance and regulation of neurotransmitter levels are critically important. Over the past few years we have characterized tyramine beta-hydroxylase, (Tbh) the putative rate-limiting enzyme controlling the octopamine synthesis in a variety of insects. We are now examining the factors that contribute to Tbh activity, including substrate and co-factor transport and availability in an attempt to understand cell to cell variations in octopamine levels. Most recently, we have identified a novel gene and gene product with high strucutural similarity to Tbh - we are especially interested its structure, function, and relationship to Tbh.

Publications and Presentations

Lehman, H.K., Murgiuc, C.M*, and Hildebrand, J.G. Characterization and developmental regulation of tyramine ß-hydroxylase in the CNS of a moth Manduca sexta. Insect Biochemistry and Molecular Biology 30: 377-386, 2000.

Mark Hodges*. Establishing a neuronal culture of identifiable octopaminergic neurons. Senior Thesis in Neuroscience. 2007.

Ellen Griffin*. Copper transport in the CNS of Drosophila melanogaster. Senior Thesis in Neuroscience. 2008.

Lehman, H.K. Bertino, S, Rico, C. Bond, D. and Berry, N. TBHR, a gene with similarities to tyramine beta hydroxylase. 37th annual meeting of the Society for Neuroscience, Washington, DC. 2008.

 

Octopamine and Behavior

Ultimately, our goal is to relate factors that are responsible for changes in octopamine synthesis to specific insect behaviors. We continue to develop behavioral assays to test our notion that multiple factors control octopamine levels and in turn, mediate specific octopamine-modulated behaviors.

Publications and Presentations

Lehman, H.K., Klukas, K.A., Gilchrist, L.S., and Mesce, K.A. Steroid regulation of octopaminergic expression during metamorphic development of the moth, Manduca sexta. Journal of Comparative Neurology 424: 283-296, 2000.

Lehman, H.K., Schultz, D.J., Barron, A., Wraight,L., Hardison,C., Whitney, S., Takeuchi, H. and Robinson, G.E. Behavioral division of labor in honey bees: the role of tyramine beta-hydroxylase. Journal of Experimental Biology 209: 2774-2784, 2006.