Is nerve growth factor required for the survival of retinal ganglion cells during development?

Staining for nerve growth factor receptor was observed in the ferret's retinal ganglion cell layer, optic nerve and tract, and in the lateral geniculate nucleus and superficial layers of the superior colliculus in the prenatal period, but had disappeared by birth. Thus the incidence of this transient staining does not correspond with the ganglion cell death that is known to occur in the ferret retina during the first postnatal week.