Dual Dorsal Columns: A Review

Recent evidence indicates that Wall (1970) may have been premature in concluding that dorsal column lesions produce no discernable sensory defects. Much of the negative evidence Wall presented to support this view is inconclusive. In addition several studies have reported significant sensory deficits in animals with severed dorsal columns. On the other hand, the literature strongly supports Wall's view that dorsal column lesions cause motor disturbances. A review of the anatomical and electrophysiological literature reveals growing evidence for the dissociation of two major subsystems relaying in the dorsal column nuclei. The possible functions of these two systems are discussed.