[The structure of the superior colliculus in the microphthalmic mouse strain 944]

The structure of the superior Colliculus (CS) in congenitally blind mice was compared with that in healthy control mice. Thus Nissl staining and degeneration experiments were done resulting in differences in the Stratum opticum (SO) of the CS between microphthalmic and control mice. In microphthalmic mice the volume of SO decreases in 14% and packing density of neurons increases in 20% in comparison with controls. Terminal degeneration after lesion of the ipsilateral visual cortex is seen in the surface laminae only. This connection seems independent of visual signals.