Altered retinotectal topography in hamsters with neonatal tectal slits

Abstract

Alterations in normal retinotectal topography by mechanical disruption of fiber passage during development was studied in Syrian hamsters using both neuroanatomical and electrophysiological techniques. The mechanical block to fiber passage was created with a medial to lateral slit across the superior colliculus on the day of birth. At maturity, topographically aberrant projections were found in areas of residual scar tissue. These aberrant projections were synaptically functional, producing neurons with multiple, spatially separated visual receptive fields. No evidence was found for an orderly compression of the retinotopic map in the tectum consequent to the transitory blockage of fiber passage.