Behavioral and Brain Sciences

Open Peer Commentary
Fitch & Denenberg: Sexual differentiation of the brain

Sexual differentiation of callosal size: Hormonal mechanisms and the choice of an animal model

M. J. Baum a1a3 and S. A. Tobet a2a3
a1 Department of Biology, Boston University, Boston, MA 02215
a2 Department of Biomedical Sciences, The Shriver Center, Waltham, MA 02254
a3 Program in Neuroscience, Harvard Medical School, Boston, MA 02115


Studies of callosal sexual differentiation have concentrated on global measures of callosal size, using the rat as a model for studies of potential hormonal mechanisms. It is time to shift the study of callosal sexual differentiation to a more cellular level. Finally, there are potential problems with using the female rat as the primary model for understanding hormonal mechanisms during postnatal life.