Meeting Abstract
Visual cues are often a vital part of animal communication and courtship. While a plethora of studies have focused on the role that hormones play in acoustic communication of anurans, relatively few have explored hormonal modulation of vision in these animals. Much of what we do know comes from behavioral studies, which show that a frog’s hormonal state can affect both its visual behavior and mating decisions in significant ways. However, to fully understand how frogs use visual cues to make these mating decisions, we must first understand how their visual system processes these cues, and how hormones affect these processes. To do this, we performed electroretinograms (ERGs) to determine the retinal sensitivity of the túngara frog (Physalaemus pustulosus), a neotropical species whose mating behavior includes previously described visual cues. We performed ERGs for both scotopic and photopic conditions. Tested frogs were either non-reproductive or hormone-treated with human chorionic gonadotropin (HCG) prior to testing to determine the effect of hormonal state on visual sensitivity.We found that both sexes display higher visual sensitivity under scotopic conditions compared to photopic conditions. In addition, hormone injections significantly increased visual sensitivity of females under scotopic conditions. These results not only support behavioral findings regarding visually-guided behavior in this species, but also serve as a starting point for elucidating the mechanism of hormonal modulation of visual sensitivity.
