We use amphibians as model systems because of their simplified nervous systems and the sensitivity of their behaviors to neuropeptide modulation. We use a combination of techniques ranging from field experiments on behavior to molecular cloning of neuropeptide genes. We currently have four lines of investigation. Vocal behavior is a critical component of the social behavior of frogs and toads. We investigate how vocalizations are controlled by examining the sites and mechanisms of action of vasotocin and the gonadal steroids testosterone, dihydrotestosterone, and estradiol in the brain.
Caecilian amphibians are unique in that most species are viviparous.
Viviparity is rare in other amphibians. We are examining the neural and endocrine control of reproduction in caecilians to discover how they differ. This work includes study of brain, pituitary, gonadal, and fetal physiology. The auditory system of anuran amphibians is sexually dimorphic and seasonally variable. We are examining these changes in the auditory system by focusing on the influence of steroids and neuropeptides on neuronal electrophysiology.