Differential profiles of c-fos expression within primary cultures of mouse cerebellar granule cells stimulated with the excitatory amino acid l-glutamate: Correlation with excitotoxic outcome and derivation of a predictive index.

Exposure of mouse cerebellar granule cells to l-glutamate (Glu) at low non-excitotoxic concentrations results in a transient expression of the c-fos proto-oncogene. Higher excitotoxic concentrations of Glu result in a change in the temporal profile of c-fos expression to a delayed but sustained response. We have derived a ratio for the steady-state levels of c-fos mRNA after 30 min and 240 min of exposure to Glu, which suggests that a 240 min/30 min ratio of greater than 1 correlates with excitotoxicity (as measured by elevated LDH release), whereas a ratio of less than 1 correlates with a non-excitotoxic outcome.