REGIONAL ZINC STAINING IN POSTMORTEM HIPPOCAMPUS FROM SCHIZOPHRENIC-PATIENTS

Schizophrenia-associated deficits in learning and memory have been ass ociated with a decrease in the volume of the hippocampus, but the spec ific nature of the neuronal deficit remains unknown. Many critical aff erent pathways in the hippocampus contain ionic zinc. Alterations of t hese pathways could be manifest as a decrease in ionic zinc levels wit hin hippocampal afferent pathways. This possibility was examined in po stmortem hippocampal tissue taken from schizophrenic patients, patient s with other psychiatric disorders and matched, non-mentally ill subje cts using a modified Timm's silver staining method. The three groups e xhibited similar patterns of zinc staining within the hippocampal form ation as well as similar levels of zinc within the messy fiber project ion system. A greater prevalence of zinc staining within the inner mol ecular layer of the dentate gyrus was observed in female as compared t o male donors and in older as compared to younger donors. The results of the present study demonstrate that loss of ionic zinc within the hi ppocampus does not appear to be part of the pathology of schizophrenia .