In vitro behavior of granule cells from Staggerer and Weaver mutants of mice.

The survival, in monolayer culture, of cerebellar granule cells from the cerebellar mutants Staggerer and Weaver was studied to examine whether the observed in vivo granule cell degeneration is intrinsic or environmentally induced. Granule cells in vitro can be identified by means of a combination of criteria including their size, shape, nuclear morphology, relative proportion of the total cell population, and failure to take up gamma-aminobutyric acid (GABA) in the presence of several other cell types which do. Cultures from both Staggerer and Weaver cerebella had surviving granule cells for at least 3 weeks in vitro. Therefore, since the mice used as the source of the cells were 7 days of age, the degeneration observed in vivo cannot be a case of irreversibly programmed cell death determined before postnatal day 7. While the behavior of Weaver granule cells is essentially the same as littermate controls, cells from Staggerer cerebella both clump less and survive considerably longer than those from wild-type. The role of intrinsic granule cell differences vs. primary changes in some other cell type is discussed.