NMDA INDUCES APOPTOSIS AND NECROSIS IN NEURONAL CULTURES - INCREASED APP IMMUNOREACTIVITY IS LINKED TO APOPTOTIC CELLS

In rat neuronal cultures exposed for a prolonged period (16 h) to a lo w concentration of N-methyl-D-aspartate (NMDA; 20 mu M) two different types of neuronal death were observed, necrosis and apoptosis. The imm unocytochemical study of necrotic neurons revealed the absence of amyl oid precursor protein (APP) labeling in the cytoplasmic region. In con trast, neuronal apoptosis was associated with an increase in cytoplasm ic APP immunoreactivity. In addition, the presence of extracellular AP P was also detected around some apoptotic neurons, suggesting that apo ptosis could contribute to the presence of extracellular APP. (C) 1997 Elsevier Science Ireland Ltd.