β-Amyloid protein load is relatively uniform throughout neocortex and hippocampus in elderly Alzheimer's disease patients

Abstract

β-Amyloid protein immunoreactivity in neocortex and hippocampus of Alzheimer's disease and control brains has been measured using an automatic image analysis system. Successive fields from the pial surface to white matter in 4 neocortical sites, parahippocampal gyrus and along the pyramidal cell layer in the hippocampus have been measured using a number of variables including: area fraction or load, counts per unit area and deposit size. In Alzheimer's disease β-amyloid protein load in neocortex and hippocampus was significantly greater than in non-demented age-matched controls. β-Amyloid protein load, as measured by size variables, was relatively uniform throughout the neocortex in elderly Alzheimer's disease patients. However, greater variability in deposition was measured in parahippocampal gyrus and hippocampus than in neocortex. Size and density variables used to measure β-amyloid protein deposition were not correlated with age although there was a tendency for the cortical load to decrease with age beyond 80 years.