Persistent memory dysfunction is associated with bilateral hippocampal damage following experimental brain injury.

Memory dysfunction following head injury is a prominent feature in humans, yet the biological basis of this abnormality remains unknown. Following parasagittal fluid-percussion (FP) brain injury in the rat, we have previously observed profound spatial memory dysfunction relatively soon following injury (i.e. at 42 h). In the present study, we show that this memory dysfunction persists for at least 2 weeks following FP brain injury, and that it is associated with a selective bilateral loss of neurons in the dentate hilar region of the hippocampus. Given the important role of the hippocampus in memory, these observations may provide a potential anatomic substrate to explain, in part, the development posttraumatic memory deficits.