INCREASE IN ENKEPHALIN-LIKE IMMUNOREACTIVITY IN HIPPOCAMPI OF ADULTS WITH GENERALIZED EPILEPSY

The changes of opioid peptide reactivity in seizure activity have been well studied in animals. Increased enkephalin and dynorphin immunorea ctivity in the hippocampi of animals are interpreted as the result of seizure induced messy fibre sprouting. We studied the hippocampi of si x patients with a history of long-standing grand mal seizures and six age-matched control patients with no history of epilepsy or neurologic disease, using frozen sections which were immunostained with antibodi es against Leu-enkephalin and Met-enkephalin. The staining intensity i n the CA3, CA4 and internal molecular layer of the dentate fascia in e ach case was quantified using optical densitometry image analysis. The CA3 and CA4 of the epileptic hippocampi showed highly significant inc rease in Leu-enkephalin-like immunoreactivity compared to the controls (P < 0.005) while the inner molecular layer showed only significant i ncrease (P<0.05). Met-Enkephalin-like immunoreactivity was only signif icantly increased in CA4 of the epileptic hippocampi (P < 0.05).