Fig. 1

Microglial cells express functional amylin receptors. a Primary cultures of human fetal microglia (HFMs) that are stained with microglial antibody, Iba-1 (green), and DyLight-594-labeled lectin (red). b These primary cultured HFMs were also stained for the two dimeric proteins that are components of the amylin receptor 3 (AMY3) subtype, the calcitonin receptor (CTR), and the receptor-associated membrane protein 3 (RAMP3). c Cultured HFMs were loaded with the fluorescent intracellular calcium dye, Fluo-8L-AM (green), and with lectin (red), an in vivo microglial marker. Arrowheads indicate cells from which Ca²⁺ signals were recorded. The same cell culture is also stained with lectin (red). The field in c shows that a majority of cells are microglia. d Summary of data on intracellular calcium changes after human amylin (hAmylin) and Aβ_1–42 without and with application of the amylin receptor antagonist, AC253 in HFM (*p < 0.05, n = 123 cells in 12 culture wells from four different batch of the culture cells). The candidate traces for intracellular calcium changes are illustrated in e–i. Elevations of Ca²⁺induced by acute (30 s) application of either hAmylin (1 μM, e) or Aβ_1–42 (1 μM, f). The changes in Ca²⁺ were blocked by AC253 (10 μM, g–i). Traces correspond to cells identified in c with arrowheads. Scale bar = 20 μm