Mapping the auditory central nervous system of Xenopus laevis with 2-deoxyglucose autoradiography

We report here on our use of 2-deoxyglucose autoradiography to identify acoustically-sensitive nuclei in the brain of the South African clawed frog, Xenopus laevis. The superior olive, lateral lemniscus, torus semicircularis, and posterocentral thalamus all selectively accumulated radioactively labeled deoxyglucose during acoustic stimulation. In frogs with middle ear bones removed on one side, the laminar nucleus of the torus was more heavily labeled on the side opposite the intact ear. Some cells within this area are known to concentrate sex hormones. This finding is, to our knowledge, the only example of a hormone-sensitive auditory nucleus in vertebrates.