| Title: | Characterization of an alarm pheromone secreted by amphibian tadpoles that induces behavioral inhibition and suppression of the neuroendocrine stress axis |
| Author(s): | Fraker ME; Hu F; Cuddapah V; McCollum SA; Relyea RA; Hempel J; Denver RJ; |
| Address: | "Department of Ecology and Evolutionary Biology, The University of Michigan, Ann Arbor, MI 48109-1048, USA" |
| DOI: | 10.1016/j.yhbeh.2009.01.007 |
| ISSN/ISBN: | 1095-6867 (Electronic) 0018-506X (Linking) |
| Abstract: | "Many species assess predation risk through chemical cues, but the tissue source, chemical nature, and mechanisms of production or action of these cues are often unknown. Amphibian tadpoles show rapid and sustained behavioral inhibition when exposed to chemical cues of predation. Here we show that an alarm pheromone is produced by ranid tadpole skin cells, is released into the medium via an active secretory process upon predator attack, and signals predator presence to conspecifics. The pheromone is composed of two components with distinct biophysical properties that must be combined to elicit the behavioral response. In addition to the behavioral response, exposure to the alarm pheromone caused rapid and strong suppression of the hypothalamo-pituitary-adrenal (HPA) axis, as evidenced by a time and dose-dependent decrease in whole body corticosterone content. Reversing the decline in endogenous corticosterone caused by exposure to the alarm pheromone through addition of corticosterone to the aquarium water (50 nM) partially blocked the anti-predator behavior, suggesting that the suppression of the HPA axis promotes the expression and maintenance of a behaviorally quiescent state. To our knowledge this is the first evidence for aquatic vertebrate prey actively secreting an alarm pheromone in response to predator attack. We also provide a neuroendocrine mechanism by which the behavioral inhibition caused by exposure to the alarm pheromone is maintained until the threat subsides" |
| Keywords: | "*Animal Communication Animals Corticosterone/*metabolism Cues Hypothalamo-Hypophyseal System/metabolism *Inhibition, Psychological Larva/*metabolism Peptides/metabolism Pheromones/*metabolism Pituitary-Adrenal System/metabolism Ranidae/*metabolism Skin/me;" |
| Notes: | "MedlineFraker, Michael E Hu, Fang Cuddapah, Vindhya McCollum, S Andy Relyea, Rick A Hempel, John Denver, Robert J eng DK20572/DK/NIDDK NIH HHS/ Research Support, N.I.H., Extramural Research Support, U.S. Gov't, Non-P.H.S. 2009/05/28 Horm Behav. 2009 Apr; 55(4):520-9. doi: 10.1016/j.yhbeh.2009.01.007. Epub 2009 Jan 30" |
