Transneuronal changes in the optic tectum following eye enucleation in the newborn rat

Following unilateral eye enucleation, degenerated neurons were observed in the affected tectum. However, dead cells also were present in the ipsilateral tectum, i.e., on the side which does not receive input from the enucleated eye. Further, the degeneration pattern observed in the experimental animals was similar to that observed in control unoperated animals. From these results we concluded that within the period studied, eye enucleation does not cause cell death to the neurons onto which the optic tract projects. Rather, the dead cells observed in the tectum are due to normal cell death that occurs in embryological development. The reduction in volume that occurs to the affected tectum following eye enucleation is attributed to an absence of the optic tract rather than to a neuronal loss.