Molecular events involved in neuronal death induced in the mouse hippocampus by in-vivo injection of kainic acid.

Apoptosis results from the activation of a programmed cellular cascade involving several mechanisms. In the present study, we have investigated the implication of three molecules of this cascade, p53, Bax and caspase-3, in neuronal death induced by kainic acid (KA) administration in mouse hippocampus. Using immunocytochemistry, western blot and quantification of enzyme activity, we observed in p53+/+ and p53-/- animals that KA induced neuronal death by both p53-dependent and independent pathways. Moreover, apoptosis (labeled by TUNEL) and the increase of bax and caspase-3 protein expression after the neurotoxic insult appeared to clearly depend on p53 expression.