Agenesis of the corpus callosum (ACC) is a congenital defect. In some human and animal types, neuronal fibers which ordinarily would dross the midline during fetal development instead run in a rostral-to-caudal direction and terminate in the ipsilateral cortex, forming Probsts bundles (PB). We will do electrophysiology experiments to study tissue slices from PBs from a mouse strain which consistently exhibits ACC. We will investigate if the PB axons conduct action potentials and if the fibers form functional glutamatergic and GABAergic synapses.