Vincent Dionne

vdionne@bu.edu

Cell and Molecular
Neurobiology

Marine Biology

Professor of Biology and Director of the Boston University Marine Program
Ph.D., University of Arizona, Tucson, 1971

Neurobiology and mechanisms of olfactory transduction

My primary research interest is to understand the cellular and molecular events used by olfactory neurons to detect and discriminate odors. The olfactory system evolved from the first chemosensory mechanisms. These were present in the earliest animals where the chemical senses were crucial for survival, providing organisms with an ability to find food and mates. The structure of the modern olfactory system is remarkably conserved across different species and phyla, suggesting that this ancient sense depends upon certain robust, but still obscure, biological principles. In spite of the relatively simple architecture of the olfactory system, we are still learning how it acquires and processes sensory information. There are three main reasons for our poor understanding. First, there are no basic principles for organizing odors in terms of critical functional parameters. Second, except for the peripheral portion of each sensory neuron, virtually the entire olfactory system is located in the brain, making it relatively inaccessible for many types of study. Third, there is no universal mechanism for transducing odor signals; rather, several different transduction pathways are used, even for individual odors.

Odors are transduced in olfactory receptor neurons by stimulating intracellular processes that modulate membrane ion channels. Electrophysiological data suggest that the responses of olfactory neurons to odors are more diverse than initially believed, and that some if not all odors can elicit several different responses by affecting several different types of channels, usually in different cells. This allows an odor to excite some neurons while it inhibits others, thereby eliciting a complex pattern of activity from the myriad of receptor neurons found in the olfactory epithelium. Diverse transduction mechanisms may be required for odor discrimination.

Delay RJ, Dionne VE. 2002. Two second messengers mediate amino acid responses in olfactory sensory neurons of the salamander, Necturus maculosus. Chem Senses. Oct;27(8):673-80.

Eisthen HL, Delay RJ, Wirsig-Wiechmann CR, Dionne VE. 2000. Neuromodulatory effects of gonadotropin releasing hormone on olfactory receptor neurons. J Neurosci. Jun 1;20(11):3947-55.

Dionne VE. 1998. New kid on the block: a role for the Na/Ca exchanger in odor transduction. J Gen Physiol. Nov;112(5):527-8.

Q.Zhou, G.Hinkle, M.L.Sogin and V.E.Dionne. 1997. Phylogenetic analysis of olfactory receptor genes from mudpuppy (Necturus maculosus). Biological Bulletin, 193:248-250.

R.J.Delay, A.E.Dubin and V.E.Dionne. 1997. A cyclic nucleotide-dependent chloride conductance in olfactory receptor neurons. Journal of Membrane Biology 159:53-60.

A.E. Dubin and V.E. Dionne. 1994. Action potentials and chemosensitive conductances in the dendrites of olfactory receptor neurons suggest novel features for odor transduction. Journal of General Physiology 103:181-201.

A.E. Dubin and V.E. Dionne. 1993. Modulation of Cl-, K+ and nonselective cation conductances by taurine in olfactory receptor neurons of the mudpuppy, Necturus maculosus. Journal of General Physiology 101:469-485.

P. Nef, I. Hermans-Borgmeyer, H. Artieres-Pin, L. Beasley, V.E. Dionne and S.F. Heinemann. 1992. Spatial pattern of receptor expression in the olfactory epithelium. Proceedings of the National Academy of Sciences USA 89:8948-8952.

V.E. Dionne. 1992. Chemosensory responses in isolated olfactory receptor neurons from Necturus maculosus. Journal of General Physiology 99:415-433.

If you would like to find out more information regarding Vince Dionne's research you can write to him at:
5 Cummington Street, Boston, MA 02215; or e-mail him at vdionne@bu.edu.