Histopathological changes of the hippocampus neurons in brain injury

The glial fibrillary acidic protein (GFAP) is known as a peculiar marker of mature astrocytes of the central nervous system (CNS). However, we found distinct immunopositivity to a monoclonal anti-GFAP reagent in the hippocampus neurons in head injury fatalities. The present study investigated the neuronal and neuroglial GFAP-immunopositivity in the hippocampus in a series of head injury cases, which included acute and subacute/delayed deaths (n=17 and n=73, respectively), and acute cardiac death (n=13), delayed death due to multiple organ failure from non-head injury (n=6), and pneumonia (n=9) cases were examined as controls. GFAP-immunopositivity in the neurons was frequently observed in CA4, CA3 and CA2 regions in cases of subacute/delayed head injury death that showed marked brain swelling accompanied by secondary brain stem hemorrhages, showing an inverse relationship to that in astrocytes. These findings suggest possible induction of GFAP or a related protein in hippocampus neurons depending on the severity of brain swelling following head injury.