Thalamic afferents from the dorsal column nuclei. An experimental anatomical study in the rat

Abstract The distribution of axons originating in the dorsal column nuclei has been studied using the Nauta technique on brains witth lesions restricted to small parts of the gracile and cuneate nuclei. The caudal area of each nucleus projects contralaterally to the ventrobasal complex in a topographical manner and in small amount to the pars medialis of the medial geniculate body. In addition, the rostral part of each nucleus sends axons to the contralateral zona incerta, anterior pretectal nucleus and posterolateral complex within the diencephalon as well as to the collicular plate and pontine protuberance of the brain stem. There is no clear evidence of a projection to the area comparable to the posterior thalamic complex of the cat. This work establishes the identity of some of the cytoarchitectonic divisions of the rat diencephalon, and indicates that the rostro‐caudal differences shown for the dorsal column nuclei are reflected in their ascending projections.