Heather L. Eisthen

Associate Professor

Ph.D., Indiana University, 1992

342 Natural Science Building
Office Telephone: 517-353-1953
eisthen@msu.edu
Research website

Neuroethology, Evolutionary and Developmental Neurobiology

We are interested in evolutionary changes in the nervous system and behavior. How do these changes occur? What happens to behavior as the brain evolves? As a model system, our research focuses on the olfactory system and olfactory-guided behavior in amphibians. Most of our current studies involve axolotls, Ambystoma mexicanum, and tiger salamanders, Ambystoma tigrinum. We use a combination of techniques and approaches, including behavioral observation, electrophysiology, neuroanatomy, and developmental manipulation.

Our recent work focusses on the evolution and function of the vomeronasal system and terminal nerve. The vomeronasal organ first appears as a discrete structure in tetrapods, although elements of the system are present in fishes. Although the vomeronasal system is commonly portrayed as being specialized for pheromone detection, its function relative to the main olfactory system is actually unclear. We are currently pursuing electrophysiological and behavioral studies to try to understand the function of the vomeronasal system in axolotls. The terminal nerve arose earlier, probably in early jawed vertebrates. Our studies indicate that the terminal nerve functions to regulate odorant responses in the olfactory epithelium in response to changing behavioral and physiological contexts.

Students in the lab are encouraged to pursue their own research interests within the general area of biology that includes the study of the evolution of the nervous system and behavior.

Representative Publications

Mouosley A., G. Polese, N.J. Marks, H.L. Eisthen. 2006. Terminal nerve-derived neuropeptide Y modulates physiological responses in the olfactory epithelium of hungry axolotls (Ambystoma mexicanum). J Neurosci 26: 7707-7717.

Eisthen, H.L., G. Polese. 2006. Evolution of vertebrate olfactory subsystems. In Evolution of Nervous Systems, Vol. 2: Non-mammalian Vertebrates (J.H. Kaas, ed). Academic Press, Oxford, UK, pp. 355-406.

Baxi, K.N., K.M. Dorries, H.L. Eisthen. 2006. Is the vomeronasal system really specialized for detecting pheromones? Trends Neurosci 29: 1-7.

Park, D., J.M. McGuire, A.L. Majchrzak, J.M. Ziobro, H.L. Eisthen. 2004. Discrimination of conspecfic sex and reproductive condition using chemical cues in axolotls (Ambystoma mexicanum). J. Comp Physiol A 190: 415-427.

Eisthen, H.L. 2002. Why are olfactory systems of different animals so similar? Brain Behav Evol 59: 273-293.