Involvement of bcl-family expression in the spatial memory impairment induced by repeated ischemia.

In the present study, we examined the effects of repeated ischemia (10 min x 2, 1 hr interval) on spatial memory in rats in an 8-arm radial maze test compared with single ischemia (10 min x 1). Repeated ischemia produced more severe impairment of spatial memory and stronger TUNEL-positive immunoreactivity in the hippocampal CA1 region than single ischemia at 7 days after reperfusion. Moreover, repeated ischemia altered bcl-family expression, which is related to apoptosis, while this was not affected by single ischemia. These results suggest that spatial memory impairment at 7 days after repeated ischemia may be related to apoptosis in hippocampal CA1 cells.