Cultures of cerebellar granule neurons.

INTRODUCTIONPrimary cultures of granule neurons from the post-natal rat cerebellum provide an excellent model system for molecular and cell biological studies of neuronal development and function. The cerebellar cortex, with its highly organized structure and few neuronal subtypes, offers a well-characterized neural circuitry. Many fundamental insights into the processes of neuronal apoptosis, migration, and differentiation in the mammalian central nervous system have come from investigating granule neurons in vitro. Granule neurons are the most abundant type of neurons in the brain. In addition to the sheer volume of granule neurons, the homogeneity of the population and the fact that they can be transfected with ease render them ideal for elucidating the molecular basis of neuronal development. This protocol for isolating granule neurons from post-natal rats is relatively straightforward and quick, making use of standard enzymatic and mechanical dissociation methods. In a serum-based medium containing an inhibitor of mitosis, cerebellar granule neurons can be maintained with high purity. Axons and dendrites can be clearly distinguished on the basis of morphology and markers. For even greater versatility, this protocol for culturing granule neurons can be combined with knockout or transgenic technologies, or used in cerebellar slice overlay assays.