Physiological State Modulates Odorant Responses in the Olfactory Epithelium of Axolotls (Ambystoma mexicanum)

Abstract

Event Abstract Back to Event Physiological State Modulates Odorant Responses in the Olfactory Epithelium of Axolotls (Ambystoma mexicanum) Nicholas W. Bellono1 and Heather L. Eisthen1* 1 Michigan State University, Department of Zoology, United States The terminal nerve is an anterior cranial nerve that contains gonadotropin releasing hormone (GnRH) and neuropeptide Y (NPY), peptides that play important roles in regulating reproduction and feeding. Our previous work suggests that responses to odorants in salamanders are modulated by both peptides in a context-dependent manner. We have now examined the effects of both peptides on responses evoked by odorants in 154 adult axolotls of both sexes in different reproductive and nutritional states. Specifically, we used electro-olfactogram (EOG) recordings to measure responses elicited by food odorants as well as those from male and female axolotls. As a control we used isoamyl acetate, an odorant with no biological significance to axolotls. For each recording we measured baseline odorant responses; then bathed the epithelium with 1 µM NPY, 10 µM GnRH, or Ringer’s solution (control) for 20 min; then washed off the peptide and recorded responses for another 40 min. In Ringer’s, we found that responses to different odorants change in diverse ways over the course of the recording, suggesting that endogenous modulation of odorant responses may be occurring in our preparation. In addition, the effects of GnRH and NPY vary with the animal’s sex as well as its reproductive and nutritional state in a way that depends on the behavioral significance of the odorant stimulus. For example, the effects of GnRH on responses evoked by female odorants depend on the animal’s sex, nutritional state, and reproductive state; in contrast, the effects of NPY depend only on the animal’s nutritional state. Responses to food odorants are modulated very differently: GnRH has no effect, and the effects of NPY depend on the animal’s sex and nutritional state. These studies contribute to understanding the ways in which the vertebrate brain regulates incoming sensory activity to emphasize stimuli that are most relevant to the animal’s current physiological state and behavior. Acknowledgements Supported by funding from US National Science Foundation (IOS 0817785), Michigan State University College of Natural Science, and the Marine Biological Laboratory. Keywords: GnRH, Neuromodulation, NPY, Olfaction, Physiology, Urodela Conference: ISAREN 2011: 7th International Symposium on Amphibian and Reptilian Endocrinology and Neurobiology, Ann Arbor, United States, 11 Jul - 13 Jul, 2011. Presentation Type: Oral Presentation Topic: Brain and behavior Citation: Bellono NW and Eisthen HL (2011). Physiological State Modulates Odorant Responses in the Olfactory Epithelium of Axolotls (Ambystoma mexicanum). Front. Endocrinol. Conference Abstract: ISAREN 2011: 7th International Symposium on Amphibian and Reptilian Endocrinology and Neurobiology. doi: 10.3389/conf.fendo.2011.03.00003 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 11 Jul 2011; Published Online: 09 Aug 2011. * Correspondence: Dr. Heather L Eisthen, Michigan State University, Department of Zoology, East Lansing, MI, 48824, United States, eisthen@msu.edu Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Nicholas W Bellono Heather L Eisthen Google Nicholas W Bellono Heather L Eisthen Google Scholar Nicholas W Bellono Heather L Eisthen PubMed Nicholas W Bellono Heather L Eisthen Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.