Electrical properties of axons within probst bundles of acallosal mice and callosi that have reformed upon glial-coated polymer implants.

Lesioning of the developing cerebral midline and corpus callosum of mice results in the formation of bilateral masses of axons known as Probst's longitudinal bundles. These ectopic axons were examined using an in vitro brain slice technique, and they were found to be functional and to have electrical properties that were similar to those of the unlesioned corpus callosum at a comparable age. When a nitrocellulose bridge is properly oriented at the site of the callosal lesion in neonates, the implant will support the migration of glia which, in turn, promote the redirection of callosal axons across the midline. These axons were also analyzed by in vitro brain slice techniques, and they were found to be functional and to have electrical properties that were similar to the unlesioned corpus callosum with respect to conduction velocity and chronaxie but dissimilar with respect to charge threshold and rheobase current.