High selective expression of α7 nicotinic receptors on astrocytes in the brains of patients with sporadic Alzheimer's disease and patients carrying Swedish APP 670/671 mutation: a possible association with neuritic plaques

Evidence for Astrocytosis in Prodromal Alzheimer Disease Provided by 11C-Deuterium-L-Deprenyl: A Multitracer PET Paradigm Combining 11C-Pittsburgh Compound B and 18F-FDG

“…The increased 11 C-DED binding in these patients might be related to an increased number of astrocytes reacting to greater quantities of Ab. Activity of MAO-B increases in AD patients' brains, and the enzyme is overexpressed in reactive astrocytes that colocalize with Ab plaques (18)(19)(20). The fact that the MCI PIB1 patients demonstrated the highest 11 C-DED binding (slope) of the 3 groups possibly suggests that reactive astrocytosis could be an early dynamic phenomenon in the time course of AD; this finding is supported by greater 11 C-DED binding in the earliest Braak stages (I-II) (20) of AD postmortem brain tissue.…”

“…Postmortem investigations (21,39) have shown that in vivo 11 C-PIB retention is strongly correlated with the 11 C-PIB binding in postmortem tissue throughout the brain. It is also known that of the 2 main types of Ab deposits (neuritic and diffuse), reactive astrocytes and activated microglia are associated only with the neuritic type (19). If 11 C-PIB in vivo labels all fibrillar amyloid but only neuritic plaques are surrounded by reactive astrocytes, then this might partially explain the absence of correlation between the 11 C-DED and 11 C-PIB tracers.…”

“…Activity of MAO-B increases in AD patients' brains; the enzyme is overexpressed in reactive astrocytes, and significant numbers of astrocytes surround both fibrillar and diffuse Ab plaques in postmortem AD brain tissue (18,19). A recent autoradiography study (20) suggested 11 C-DED as a suitable in vivo PET ligand for assessing MAO-B in AD brains.…”

Astroglial calcium signalling in Alzheimer's disease

“…Chronic treatment with low β-amyloid concentrations (0.1 -100 nM), however, up-regulates several cholinoreceptors including those containing α7, α4 and β2 subunits [127]. Increase in astroglial expression of α 7AChR was also detected in human post-mortem samples obtained from both sporadic and familial forms of AD [128]. Another receptor which seems to be positively modulated by β-amyloid is Gprotein coupled metabotropic Ca 2+ -sensing receptor (CaSR).…”

Evidence for the Involvement of Apoptosis-Inducing Factor–Mediated Caspase-Independent Neuronal Death in Alzheimer Disease

“…30 Sections were deparaffinized and rinsed in Tris-NaCl buffer (TBS) (0.05 mol/L Tris, 0.15 mol/L NaCl, pH 7.6) and then treated with 1% hydrogen peroxide (30 minutes) to quench endogenous peroxidase activity. For antigen retrieval, sections were boiled in 0.05 mol/L citrate-buffered saline (pH 6.0).…”