Dorsal root projections to nucleus cuneatus of the cat.

Abstract

Following single, dorsal rhizotomies in 9 cats, axonal degeneration was traced ipsilaterally throughout nucleus cuneatus with the Nauta-Laidlaw and Fink-Heimer 1 silver stains. 1. (1) Cytoarchitectonic differences permitted a division of the nucleus into a rostral 'reticular' region and a caudal 'cell nest' region. 2. (2) Degeneration from each root was found at all rostrocaudal levels of the nucleus, but in unequal amounts. 3. (3) Two patterns of degeneration were evidenced with the Nauta-Laidlaw technique: (A) focal; characterized by localized areas of degeneration and minimal intersegmental overlap which was found in the caudal 'cell nest' region, and (B) diffuse; exhibiting less discrete..