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 [email protected]
a2 Department of Biomedical Sciences, The Shriver Center, Waltham, MA 02254 [email protected]
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.