Dissertation Research: Neuroendocrine mechanisms regulating sexual behavior in female túngara frogs

The decision to reproduce is one of the most important decision an animal makes. Females invest a large proportion of energy in reproduction and the timing of reproduction is therefore highly regulated. The timing of reproductive behavior is regulated through neural modulation by reproductive hormones, such as estradiol. The primary goal of the proposed research is to better understand how estradiol modulates neural systems to regulate the expression of reproductive behavior. An important component of reproductive behavior includes those behaviors that mediate a female's choice of a mate. Using túngara frogs, the researchers will investigate the effects of estradiol on the sensory systems that females use to respond to male mating signals. Female frogs choose mates based on their vocalizations, and they respond preferentially to vocalizations of their own species when their estradiol levels are high compared to when their estradiol levels are low. This research will test if estradiol influences activity in the auditory system through changes in neurochemicals in the brain. To measure neural activity, the researchers will assess changes in gene expression that are correlated with neural activity. They predict that estradiol causes females to respond selectively to male vocalizations because of its effects on catecholamines, a class of neurochemicals, in the auditory system. The results of this research will broaden our understanding of how brain function is modulated by hormones during critical behavioral decisions such as mate choice. The project will also provide training opportunities for graduate and undergraduate students.