[The microphthalmic 944 strain of mice as a model for ontogenesis studies of the visual system. Volumetric and Golgi studies on the lateral geniculate body in the pars dorsalis].

We investigated a strain of mice with recessive microphthalmy. The mutant mice were compared with phänotypically healthy animals of the same litter using following parameters: daily pattern of motor activity, EEG pattern of the visual cortex, relative brain weight, volume of the Corpus geniculatum laterale pars dorsalis (CGLd), packing density and total number of cells in the CGLd, size of neurons (perikarya, size of dendritic domains DF), structure of dendrites (number of dendrites, branching points VZP, distribution of dendritic density in relation to the perikaryon Is). Neuromorphological parameters were investigated at postnatal days (pd) 5, 10, 15 and 20. At pd 5 we did not find differences between mutant and phänotypically healthy animals. At pd 20 the CGLd's volume of the microphthalmic mice decreased by 30% and the packing density of neurons increased by 20% compared with the healthy animals of the same litter. We observed striking changes in VZP, Is and DF of the dendritic tree. The most stable parameter is the number of the primary dendrites which is between 4 and 5.