NEURONAL APOPTOSIS IS ASSOCIATED WITH A DECREASE IN TAU MESSENGER-RNAEXPRESSION

APOPTOSIS is a programmed cell death that occurs during the developmen t of the nervous system and in neurodegenerative disorders. Tau protei n is a microtubule-associated protein which promotes microtubule polym erization and stabilization. Apoptosis was induced in primary neuronal cultures by glutamate exposure (200 mu M, 15 min) or by serum depriva tion, and tau mRNA levels were studied by quantitative in situ hybridi zation in apoptotic and non apoptotic neurons. Compared to controls, t au mRNA expression was decreased in apoptotic neurons produced by exci totoxicity or trophic support withdrawal. Under these conditions, resi stant neurons to apoptosis display either increased tau mRNA levels af ter glutamate exposure or a stable tau mRNA expression after serum dep rivation. In conclusion, in this in vitro model, neurons which are res istant and sensitive to apoptosis can be differentiated according to t au mRNA expression. (C) 1998 Rapid Science Ltd.