Neocortical glial cell numbers in Alzheimer's disease. A stereological study

Most studies agree that specific regions of the hippocampus and specific subcortical regions show neuronal loss in Alzheimer's disease (AD). The aim of the study was to use design-based stereological methods to obtain an estimate of the total glial cell population in 14 AD cases and 20 controls to determine whether brains from AD patients have a different number of neocortical glial cells than controls. The mean total number of neocortical glial cells was 25.9 x 10(9) for the AD group and 29.1 x 10(9) for the control group, 2p = 0.18. The mean total number of neocortical neurons was 18.9 x 10(9) for the AD group and 21.2 x 10(9) for the control group, 2p = 0.059. Estimates of the sum of all glial cells and neurons in the neocortex were in the order of 50 billion cells with a glia to neuron ratio of 1.37 in both groups.