VENs in human anterior cingulate cortex are vulnerable to AD pathology, particularly in later stages of pathogenesis. Their densities do not change throughout aging in individuals with average cognition, and they are more numerous in SuperAgers.

Basal forebrain cholinergic neurons (BFCN) are selectively vulnerable in Alzheimer's disease (AD). We have shown that the majority of BFCN in the human brain contain the calcium binding protein calbindin-D28K (CB), a large proportion lose their CB in the course of normal aging, and the BFCN which degenerate in AD lack CB. Here we investigated the relationship between CB in the BFCN and the process of tangle formation in AD using antibodies to Tau epitopes that appear early, intermediate or late in the process of tangle formation. Very small percentages (0-3.7%) of CB-positive BFCN contained pre-tangles/tangles and very small percentages (0-5%) of the total BFCN pre-tangles/tangles were in CB-immunoreactive neurons. The number of CB-positive BFCN which contained Tau immunoreactivity was highest for the early epitope and lower for intermediate epitopes. A late appearing epitope was absent from CB-positive BFCN. Age-related loss of CB appears to coincide with tangle formation in the BFCN and is associated with the full range of Tau pathology, including late appearing epitopes.

Microglia are immune cells of the brain that display a range of functions. Most of our knowledge about microglia biology and function is based on cells from the rodent brain. Species variation in the complexity of the brain and differences in microglia response in the primate when compared with the rodent, require use of adult human microglia in studies of microglia biology. While methods exist for isolation of microglia from postmortem human brains, none allow culturing cells to high passage. Thus cells from the same case could not be used in parallel studies and multiple conditions. Here we report a method, which includes use of growth factors such as granulocyte macrophage colony stimulating factor, for successful culturing of adult human microglia from postmortem human brains up to 28 passages without significant loss of proliferation. Such cultures maintained their phenotype, including uptake of the scavenger receptor ligand acetylated low density lipoprotein and response to the amyloid-β peptide, and were used to extend in vivo studies in the primate brain demonstrating that inhibition of microglia activation protects neurons from amyloid-β toxicity. Significantly, microglia cultured from brains with pathologically confirmed Alzheimer’s disease displayed the same characteristics as microglia cultured from normal aged brains. The method described here provides the scientific community with a new and reliable tool for mechanistic studies of human microglia function in health from childhood to old age, and in disease, enhancing the relevance of the findings to the human brain and neurodegenerative conditions.