Inhibition of protein synthesis during repetitive cortical spreading depression

The effect of cortical spreading depression (CSD) on cerebral protein synthesis (CPS) was examined. CSD was evoked in normal rats with KCl, and CPS was measured autoradiographically with [1-14C]leucine. Average rates (mean +/- SD) of CPS in layers I-IV of cortex decreased significantly from 10.7 +/- 0.6 (sham-operated controls; n = 4) to 6.7 +/- 0.7 nmol/g/min (n = 4; p < 0.01) and in layers V-VI from 10.9 +/- 0.5 to 9.4 +/- 0.4 nmol/g/min (p < 0.05) during 60 min of repetitive CSD. Spreading depression did not affect CPS rates in other subcortical brain regions. These results indicate that KCl-evoked CSD induces inhibition but not suppression of cortical protein synthesis.