Proliferative activity in incubated slices of immature rat cerebellum

Slices of 8-day-old rat cerebella were prepared with a tissue chopper, incubated in an oxygenated Krebs-Henseleit solution followed by processing for histology. One micrometer thick sections of resin-embedded slices were stained with Toluidine blue. The external granular layer was shown to maintain its normal proliferative activity up to 3 h of incubation as suggested by the presence of all mitotic phases within this period and by a roughly 50% increase in mitotic index upon a 90-min exposure of incubated slices to 20 microM vinblastine. On this basis the incubated slice of the immature rat cerebellum may serve as a simple tool for the rapid histological testing of short-term mitogenic or cytostatic effects and the vulnerability of a brain germinal layer.