Increased dendritic MAP2 expression in the hippocampus in schizophrenia

Microtubule associated proteins (MAPs) are central to the development of no rmal neuronal cytoarchitecture and have been reported to be altered in schi zophrenia. In 12 schizophrenic (DSM-III-R criteria) and 12 control hippocam pi, we estimated the MAP2 immunoreactive dendritic length using antibodies that recognize total MAP2 (MAP2-T), and a non-phosphorylated form of MAP2 ( MAP2-NP). Within the corona ammonis (CA) subregions, and the subiculum, we estimated, for each antibody, the length of the immunoreactive dendritic ar borisation using a stereological length estimation technique based on Bouff on's Needle principle and image analysis computer software. Controlling for the confounding effects of age and post-mortem delay, we have found an ele vation in overall MAP2-NP immunoreactive dendritic length among schizophren ic subjects in the CA3 (F = 5.9, p = 0.03), CA2 (F = 6.5, p = 0.02), CA1 (F = 8.3, p = 0.01) and subicular (F = 9.5, p = 0.008) hippocampal subregions . Similar analyses of MAP2-T immunoreactive dendritic length demonstrated s ignificant elevations in the CA1 (F = 8.3, p = 0.02), CA4 (F = 4.9, p = 0.0 4) and subicular (F = 7.4, p = 0.01) regions. The findings of this quantitative study of increased MAP2 immunoreactive de ndritic arborisation in schizophrenia are most likely to reflect either an altered dendritic arborisation or a generalised increase in levels of MAP2 with the hippocampal pyramliteratureidal neurons. These findings add to the growing indicating the presence of synaptodendritic abnormalities in schiz ophrenia. (C) 2000 Elsevier Science B.V. All rights reserved.