Neurological cholinesterases in the normal brain and in Alzheimer's disease: relationship to plaques, tangles, and patterns of selective vulnerability

Ann Neurol. 1993 Sep;34(3):373-84. doi: 10.1002/ana.410340312.


Butyrylcholinesterase (BChE) and an altered form of acetylcholinesterase (AChE) accumulate in the plaques and tangles of Alzheimer's disease (AD). The sources for these plaque- and tangle-bound cholinesterases have not been identified. We now report that AChE and BChE activities with pH preferences and inhibitor selectivities identical to those of plaque- and tangle-bound cholinesterases are found in the astrocytes and oligodendrocytes of control and AD brains. These glial-type cholinesterases are selectively inhibited by indolamines and protease inhibitors. In control brains glial-type cholinesterases appear confined to the intracellular space, whereas in patients with AD they decorate plaques and tangles as well. In control and AD brains AChE-positive glia are distributed throughout the cortical layers and subcortical white matter, whereas BChE-positive glia reach high densities only in the deep cortical layers and white matter. In non-AD control brains, the ratio of BChE to AChE glia was higher in entorhinal and inferotemporal cortex, two regions with a high susceptibility to the pathology of AD, than in primary somatosensory and visual cortex, two areas with a relatively lower susceptibility to the disease process. There was no age-related differences in the density or distribution of cholinesterase-positive glia. In comparison with age-matched control specimens, AD brains had a significantly higher density of BChE glia and a lower density of AChE glia in entorhinal and inferotemporal regions but not in the primary somatosensory or visual areas. These results suggest that glia constitute a likely source for the cholinesterase activity of plaques and tangles and that a high ratio of BChE- to AChE-positive glia may play a permissive or causative role in the neuropathology of AD.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Acetylcholinesterase / analysis
  • Acetylcholinesterase / metabolism*
  • Adult
  • Age Factors
  • Aged
  • Aged, 80 and over
  • Alzheimer Disease / enzymology*
  • Alzheimer Disease / pathology*
  • Brain / enzymology*
  • Brain / pathology*
  • Butyrylcholinesterase / analysis
  • Butyrylcholinesterase / metabolism*
  • Cholinesterase Inhibitors / pharmacology
  • Female
  • Humans
  • Male
  • Middle Aged
  • Neurofibrillary Tangles / enzymology*
  • Neurofibrillary Tangles / pathology
  • Neuroglia / enzymology*
  • Neuroglia / pathology
  • Reference Values


  • Cholinesterase Inhibitors
  • Acetylcholinesterase
  • Butyrylcholinesterase