Aberrant visual pathways in microphthalmic mice

We report results obtained in the microphthalmic strain of mice 944. Heterozygotes appear normal, but they produce litters in which typically between 2 and 5 offspring exhibit microphthalmia. As a result these animals are blind. Our investigations using the fluorescent tracer DiI show that in microphthalmic mice there is a small compensation for the missing retinal input by terminals or axon collaterals originating in the somatosensory thalamus. These morphological findings agree with somatosensory responses recorded in the visual cortex (EEG recordings).