Plasticity of the ipsilateral retinotectal projection in early enucleated opossums: changes in retinotopy and magnification factors.

The aberrant ipsilateral retinocollicular projection in early enucleated opossums was studied with both electrophysiological and radioautographic techniques. It was shown that the expanded projection originates from the same restricted region of temporal retina that gives origin to the normal ipsilateral projection. Furthermore, it was observed that the aberrant projection conveys a well-ordered retinotopy, with changes of the magnification factors compatible with the interpretation that ganglion cells at the borders of the ipsilaterally-projecting region display the most intense plastic response after enucleation.