Kainic acid-induced sprouting of dynorphin- and enkephalin- containing mossy fibers in the dentate gyrus of the rat hippocampus

This study utilized Timm histochemistry and immunocytochemistry to determine the prolonged effects of kainic acid on the distribution of dynorphin- and enkephalin-containing mossy fibers in the rat dentate gyrus at progressive time points following kainic acid injection. Beginning 1-2 weeks after kainic acid administration, a progressive increase in the distribution and intensity of staining for supragranular zinc, dynorphin and enkephalin was observed in the dentate gyrus. The kainic acid-induced sprouting of mossy fibers containing dynorphin and enkephalin strongly resembles the pattern observed in the dentate gyrus of humans with temporal lobe epilepsy.