BRC-BIO: Scents and sensibility: The impacts of vasotocin and humidity on chemical communication in lizards

About This Grant

Chemicals control the social lives of animals, and some compounds need to balance multifunctional roles to perform effectively. The compound arginine vasotocin (AVT) is used for both osmotic balance and social communication. All animals rely on AVT, or a related hormone, for similar functions and use chemical communication to transmit social information between members of their own species. Thus, determining how AVT affects chemical communication will offer broad insights into the mechanisms governing social dynamics. Since environmental humidity impacts both AVT secretion and the persistence of chemical signals used in communication, the relationship between AVT and chemical communication could depend on humidity. As behavioral thermoregulators, lizards occupy places with varying humidities, and many species rely on chemical signaling for territorial maintenance. This project compares two species of Sceloporus Spiny lizards representing opposite extremes in habitat humidity to ask about the relative impacts of humidity on chemical communication. This project will train undergraduates to conduct vertebrate research using techniques in animal behavior, neuroscience, and chemical ecology in the field and lab. A research technician will gain extensive training in experimentation, lab management, field research, undergraduate mentorship, and research dissemination as preparation for a career in STEM. The chemical analysis pipeline created through this project will offer engaging workshops for graduate students and numerous undergraduate research opportunities beyond the scope of this grant. This project also provides resources for outreach to educate the community about local lizard populations. The goal of this work is to determine whether AVT modulation of chemical communication is humidity-dependent in lizards by investigating chemical production in signalers and receiver responses to chemical signals. Each aim addresses a different aspect of chemical communication, comparing either behavioral responses to chemical signals, neural responses to chemical signals, or the composition of chemical signals across humidity (Low versus High) and drug (AVT versus saline) treatments. Sceloporus lizards have femoral glands that secrete chemicals used in territorial communication, and some species, such as S. undulatus, have adapted to a range of humidities. Adult males from humid temperate regions (High Humidity species, S. undulatus) or dry desert habitats (Low Humidity species, S. magister) will be captured and transported to a climate-controlled lab at Villanova University for experimentation. For both High and Low Humidity species, signalers will receive AVT or saline injections and behavioral assays will determine whether AVT in signalers impacts the 1) chemosensory behavior or 2) activation of AVT neurons in receivers. Then, researchers will 3) describe the acute and delayed impacts of AVT on chemical signal production at High and Low humidity levels in S. undulatus by treating signalers with AVT, manipulating environmental humidity, and collecting and chemically analyzing lizard glandular secretions over time. This comparative framework offers a comprehensive assessment of AVT’s humidity-dependent role in chemical communication. The data and chemical analysis pipeline generated by this project will continue to support additional undergraduate and graduate research projects, as well as foster research collaborations and community outreach. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.