General Description of the Torus and Commissural Connections

Abstract

The present studies were designed to provide more detailed descriptions of (a) the internal organization of the whole torus and (b) the input and output relations of each layer of the torus. We have been greatly aided in our studies by a simple technique for the visualization of anterograde and retrograde transport of HRP (Ebbesson et al. 1981a). It is clear from the limited number of investigations made so far that further elucidation of the tremendous inherent complexity of the torus will require several additional years of study with a variety of histological and physiological techniques. It should therefore be clear to the reader that we do not intend in this report to cover all aspects of anatomical relationships of the torus. Our descriptions as well as those of the dorsal torus in a similar study by Carr et al. (1981) do however provide sufficient new organizational information to establish a framework upon which further studies can be based.