A RETROGRADE DOUBLE-LABELING STUDY OF RETINAL GANGLION-CELLS THAT PROJECT IPSILATERALLY TO VLGN AND LPN RATHER THAN DLGN AND SC, IN ALBINO-RAT

We studied ipsilaterally projecting, double-labeled retinal ganglion c ells that have bifurcating axons by retrograde fluorescent double-labe ling in albino rats. Ten albino (Wistar, Japan Clea) rats of either se x, weighing 350-400 g were used. With the rats in a state of deep anes thesia, we pressure-injected 0.02 mu l of 15% Evans blue (EB) into the right ventral lateral geniculate nucleus (vLGN), and 4% Fluoro-gold ( FG) iontophoretically into the right posterior lateral thalamic nucleu s (LP). The animals were perfused with formol-saline 48-72 h later and both the brain and eyes were excised. The brain was sectioned coronal ly, and each retina was removed and mounted flat on a glass slide. Dou ble-labeled cells were found in the ventral temporal crescent of the r etina. In one animal the total number of ipsilaterally labeled cells w as 566, and the percentages of double-labeled vLGN and LP projecting c ells, single-labeled vLGN projecting cells, and single-labeled LP proj ecting cells were 29.8, 58.8 and 11.3, respectively.