CORRELATIVE STUDY OF THE MORPHOLOGY AND CENTRAL CONNECTIONS OF IPSILATERALLY PROJECTING RETINAL GANGLION-CELLS IN THE ALBINO-RAT

Injection of Evans Blue (EB) and 4’,6-diamidino-2-phenylindole dihydrochloride (DAPI), fluorescent dyes, into the dorsal nucleus of the lateral geniculate body (dLGN) and the ipsilateral superior colliculus (SC) of albino rats, retrogradely labelled retinal ganglion cells (RGCs). We classified these cells into three categories: (1) double-labelled, geniculate and collicular-projecting RGCs; (2) single-labelled, geniculate-projecting RGCs; and (3) single-labelled, collicular-projecting RGCs. Cell soma sizes were measured and the soma size histogram of each category was compared with the others as well as with that of the corresponding category in the contralateral retina. The mean soma size of the ipsilaterally projecting double-labelled RGCs was larger, and their soma size histogram was significantly different in comparison with those of the other two categories. On the contralateral side, the mean soma size of the RGCs labelled only from the SC was smaller, and also their soma size histogram was significantly different from those of the other two categories. On comparing both sides, only the ipsilaterally-projecting double-labelled cells had a significantly different soma size histogram and larger soma size. © 1993 Academic Press, Inc.