Ammon's horn changes in focal brain ischemia in humans.

Neuronal changes in Ammon's horn were examined immunocytochemically in 20 patients aged from 51 to 101 years, deceased in the course of ischemic lesions localized within the area supplied by vessels derived from other then Ammon's horn vascularization (middle cerebral artery). Numerous neurons within various sector of the pyramidal layer, in the dentate gyrus, subiculum and entorhinal cortex were immunopositive in reaction with antibodies to serum proteins (albumin, IgG, alpha-1-antitrypsin), indicating their damage. The distribution of damaged Ammon's horn pyramidal cells differed from the location of injured Ammon's horn neurons in experimental investigations of brain ischemia and did not indicate a selective vulnerability of pyramidal cells in the human h1 area, corresponding to the CA1 sector in animals. Contrary to experimental material, changes in the human Ammon's horn are caused by numerous overlapping factors.