Behavioral performance of rats following transient forebrain ischemia.

Rats subjected to transient forebrain ischemic injury by the method of four vessel occlusion (4-VO) develop irreversible injury to select populations of vulnerable neurons which include pyramidal cells in the CA-1 region of the hippocampus. This brain area is thought to be crucial for learning and memory. Rats subjected to 30 minutes of 4-VO, and then cerebral reperfusion were tested on a radial 8-arm maze task after they had recovered. The data shows that both 4-VO and control animals improve their performance over trials, but that 4-VO rats are impaired on "working" and "reference" tasks. The data suggest that 4-VO rats' impaired "working" performance is permanent, compared to their transient "reference" impairment. Alterations in sensorimotor activity could not account for these performance deficits since control and 4-VO rats demonstrated equivalent choice time per maze arm. Performance deficits in rats following forebrain ischemic injury may be similar to some of the cognitive deficits found in humans survivors of cerebral hypoxia-ischemia.