Development of a transient retino-retinal pathway in hooded and albino rats

Intraocular HRP injections in E16-21 embryos show that during the normal development of the central optic projections in hooded and albino rats many optic axons grow through the chiasm into the contralateral eye. This retino-retinal projection disappears shortly after birth. This suggests that an initial, imprecise guidance of growing axons is followed by a selective elimination of axons taking aberrant pathways and failing to make appropriate synapses.