Assessment of neuronal viability with Alamar blue in cortical and granule cell cultures

Alamar blue, a redox indicator of cell viability in nonneuronal systems, was used to assess neuronal viability in cultures prepared from embryonic rat cerebral cortex and neonatal rat cerebellum. Alamar blue fluorescence varied linearly with cell number and was decreased by treating cortical or cerebellar granule cell cultures with excitatory amino acids, exposing cortical cultures to hypoxia and glucose deprivation, or inducing apoptotic death in granule cell cultures by growth in medium containing a low concentration of K+. Alamar blue fluorescence may complement existing methods for measuring neuronal viability and cytotoxicity in culture and thereby contribute to the study of cellular mechanisms of neurologic disease.