KAINIC ACID-INDUCED SPROUTING OF DYNORPHIN-CONTAINING AND ENKEPHALIN-CONTAINING MOSSY FIBERS IN THE DENTATE GYRUS OF THE RAT HIPPOCAMPUS

This study utilized Timm histochemistry and immunocytochemistry to det ermine the prolonged effects of kainic acid on the distribution of dyn orphin- and enkephalin-containing messy fibers in the rat dentate gyru s at progressive time points following kainic acid injection. Beginnin g 1-2 weeks after kainic acid administration, a progressive increase i n the distribution and intensity of staining for supragranular zinc, d ynorphin and enkephalin was observed in the dentate gyrus. The kainic acid-induced sprouting of messy fibers containing dynorphin and enkeph alin strongly resembles the pattern observed in the dentate gyrus of h umans with temporal lobe epilepsy.