Central correlates of peripheral pattern alterations in the trigeminal system of the rat. II. The effect of nerve section.

The effect of trigeminal nerve section on pattern formation in the rat central nervous system was investigated. Nerve section was found to abolish all evidence of afferent segmentation in the brain stem. At thalamic and cortical levels the pattern of afferent segmentation was affected in a time-dependent fashion. The later the procedure is performed, the less severe the resultant effect. Early section abolishes all afferent segmentation, later section only within-row segmentation, and still later section has no effect on pattern formation. The results of this experiment support the hypothesis that peripheral spatial information plays an important role in pattern formation in the central trigeminal system.