Time-course expression of Bax and Bcl-2 proteins, identified as apoptosis-regulating molecules, was assessed in gerbil hippocampus following transient forebrain ischemia. Brain sections from animals sacrificed at 48, 72, 96 h and 7 days following 5 min ischemia were immunohistochemically evaluated using polyclonal antibodies specific for Bax and Bcl-2 proteins, respectively. The intensity of Bax expression in CA1 neurons increased with time and peaked at 72 h, and immediately disappeared at 96 h following 5 min ischemia. No expression of Bcl-2 in the CA1 neurons was recognized in all the time evaluated.