Effects of early retinal lesions on conduction velocity relationships in the dorsal lateral geniculate nucleus of the cat.

Bilateral retinal lesions have been made in and around the area centralis in 5 kittens 23-28 days of age. Twelve to 14 months later, microelectrode recordings were made in the LGN of these animals. Penetrations through the medial, deafferented portion of the nucleus encountered retinally innervated cells at the same rate as penetrations through the intact lateral half of the nucleus or through the LGN of normal adult cats. The correlation between orthodromic anc antidromic latency for LGN relay cells in experimental animals was reduced when compared to normal animals, and the percentage of cells receiving dual fast and slow retinal input was increased in experimental animals. These observations are interpreted as evidence that the medial portion of the LGN was reinnervated following the neonatal retinal lesions, and that the specificities that normally exist between relay cells and their retinal afferents in terms of axonal conduction velocity were not maintained during the course of this reinnervation.