During development, neurons containing gonadotropin-releasing hormone traverse fiber bundles in the nose, cross into the brain, and move through a maze of glial and axonal fibers. To test whether GnRH neurons utilize cues intrinsic to their migration route to traverse the nasal/brain boundary, tissue slices that maintain connections between the forebrain and nasal compartment were prepared from mouse embryos. Cell migration between the nasal and brain compartments was evident based on changes in cell positions after successive days in vitro.