FIGURE 1.

Influence of E. coli lipopolysaccharide (LPS) on intracellular free Ca²⁺ concentration ([Ca²⁺]_i) changes induced by glutamate (Glu) in primary neuronal cultures. (A,C) Changes of [Ca²⁺]_i induced by Glu (100 μM) alone and (B,D) in the presence of (LPS, 10 μM), in cultured neurons of the rat cerebral cortex (A,B) and cerebellum (C,D). The results of representative experiments are presented. Glu was co-applied with 10 μM Gly in Mg²⁺-free buffer. [Ca²⁺]_i changes are presented as the ratio of fluorescence signals of the low- and high-affinity Ca²⁺ indicators (Fura-FF and Fura-PE3, respectively) excited at 340 and 380 nm (F340/F380); emission was monitored at 525 ± 15 nm. Protonophore FCCP (1 μM) was added in a calcium-free buffer at the end of the experiment to release into the cytosol Ca²⁺ accumulated by mitochondria. The Ca²⁺-selective ionophore ionomycin (Iono, 2 μM, 5 mM Ca²⁺) was employed to calibrate the maximal Ca²⁺ signal of the indicators. The graphs display [Ca²⁺]_i responses to Glu of only those neurons in the field of observation, which had delayed calcium deregulation (DCD). Red line corresponds to the mean, and dot red line corresponds to the SD. Schematic of experimental design for panels A–D (E).