We study the brain regional distribution of putrescine after excitotoxic damage. After status epilepticus induced by kainic acid (9 mg/kg, i.p.) we found an increase of putrescine in all the regions analyzed. Three kind of regions can be identified according to the magnitude and persistence of the abnormal concentration of putrescine: hippocampus and cortex (9-fold 1 day, still increased 2-fold 2 weeks after injection), cerebellum and medulla oblongata+pons (2-fold 1 day after injection) and the other regions (7-8-fold 1 day, still increased 2-3-fold 1 week after injection). The histological damage was: severe, absent and moderate or low, respectively. After ataxia induced by kainic acid injection (2.34 nmols) into the cerebellum, putrescine also rises in all regions; a high concentration (9-fold) and severe damage was found in the injected cerebellar hemisphere. In conclusion, in the models studied, putrescine increases in all the regions analyzed. However, the highest concentrations and the most severe damage were found in the target regions.