Fig. 3
LPS induce Ca2+ influx in aged cultures of rat hippocampal neurons but not in young cultures. Hippocampal neurons cultured for 5–8 (young), 9–10 (mature), or >18 (aged and/or senescence) days in vitro (DIV) were loaded with fura2 and subjected to Ca2+ imaging. a–c Traces show representative single-cell [Ca2+]cyt responses to 1 μg/ml LPS and NMDA 100 μM added as indicated in 4–8 (a), 9–10 (b), and >18 DIV (c) hippocampal neurons. Pictures at the right show pseudocolor images of [Ca2+]cyt (Ratio F340/F380) before (basal) and after LPS addition in the same experiments. Bars represent 10 μm. d Effects of TLR4-activation inhibitor CAY10614 (0.5 μM) on [Ca2+]cyt in >18 DIV neurons. e Bars represent average rises in [Ca2+]cyt induced by LPS and calculated as the product of the cell fraction responsive to LPS (1% young = 1% mature, 78% aged, 66% CAY) by the Δ[Ca2+]cyt recorded in responsive cells in young neurons, mature neurons, and aged neurons treated with CAY10614 (mean ± SEM; n = 45, 24, 23 cells, respectively, from 3–4 independent cultures; *p < 0.05 compared to young; # p < 0.05 compared to aged). f Bars represent average rises in [Ca2+]cyt induced by NMDA in 10 and 20 DIV neurons. *p < 0.05 compared to 10 DIV neurons (mean ± SEM; n = 53 and 35 cells, respectively, from 10 and 6 independent cultures)