RETROGRADE TRANSPORT OF NERVE GROWTH-FACTOR FROM OLFACTORY-BULB TO OLFACTORY EPITHELIUM

NGF is produced in the olfactory bulb and transported from the bulb to cholinergic neurons in the horizontal limb of the diagonal band. Alth ough the expression of NGF receptors has been reported in olfactory ep ithelial cells, no correlation between NGF and olfactory epithelial ce lls has been found. This study aimed to define whether or not retrogra de transport of NGF occurs in the olfactory neural system using the me thod of radioluminography. I-125-labeled NGF injected into the olfacto ry bulb was taken up and transported to the olfactory epithelium 18 h after injection. This finding suggests that bulbar NGF may act as a ne urotrophic factor in olfactory epithelial cells.