LOSS OF SIGMA-BINDING SITES IN THE CA1 AREA OF THE ANTERIOR HIPPOCAMPUS IN ALZHEIMERS-DISEASE CORRELATES WITH CA1 PYRAMIDAL CELL LOSS

The densities of [H-3]1,3-di-o-tolylguanidine ([H-3]DTG) binding to sigma binding sites in the CA1 stratum pyramidale region in 7 hippocampi affected by Alzheimer's disease, were compared with densities in 7 normal hippocampi. There was an average reduction of 26% in [H-3]DTG binding in this area, which was correlated with an average 29% pyramidal cell loss in the same region. These results are consistent with experiments in animals indicating that sigma binding sites are preferentially associated with the somata of large cells.