Courtship behavior in animals typically involves gaining the attention of a potential mate by using a complicated set of behaviors: visual cues, physical contact, vocalizations, or pheromones. Many vertebrates produce pheromones that affect male-female interactions. In our salamander mating system, male pheromones are delivered during courtship when a female requires persuasion to respond to the male. This study system has focused on terrestrial salamanders because these vertebrate animals have a mating system that is strongly based on pheromone communication during courtship. What we can learn from pheromone communication in salamanders will relate to chemical communication across all vertebrates, including humans. In past work, this group has documented the effect of male courtship pheromones on female reproductive behavior. These pheromones clearly act to increase the female's receptivity to the male. This research team also has basic information about the biochemical nature of the male pheromones: non-volatile proteins that can be synthesized. This new research addresses questions on how a male's pheromone mixture actually functions to stimulate a female, with pheromone effects measured in terms of her olfactory response, brain activity, and mating behavior. Female responses to specific mixtures of synthesized pheromones will be recorded. This group expects that (a) pheromone proteins will elicit the stronger effects when used in combination, and (b) females vary in their preference for particular combinations. A strength of our proposal is that both graduate and undergraduate students will receive interdisciplinary training in at least three different research laboratories focusing on different areas of the proposal (biochemistry, behavioral science, and neurohistology), as well as field research experience collecting and maintaining salamanders. This team will continue their outreach efforts with university and local high school science programs to enhance students' understanding of scientific research.
