DNA FRAGMENTATION IN RAT-BRAIN AFTER INTRAPERITONEAL ADMINISTRATION OF KAINATE

CELL death occurs in many neuropathological conditions. However, the m echanisms governing this process(es) remain generally unknown. In this report we studied whether excitotoxic neuronal death evoked by kainic acid (KA) in rat brain is associated with ladder-like DNA fragmentati on. DNA was isolated from hippocampi, entorhinal and sensory cortices at various times following intraperitoneal KA (10 mg kg(-1)) injection s. Typical oligonucleosome-sized DNA fragmentation was observed in all three structures at 18 h and 72 h following KA administration. These findings were further confirmed by in situ nick-translation. DNA fragm entation is believed to be diagnostic for apoptosis. The clear ladders of DNA fragmentation appeared after 18 h, although slight degradation was observed as early as 12 h after KA administration.