Fig. 5
CCL2 promotes presynaptic calcium signals in spinal nociceptor terminals. a Schematic demonstration of the experimental approach for specific expression of GCaMP6s in L3/L4 DRGs in SNS-Cre mice and Ca2+ imaging in nociceptive DRG neurons and the presynaptic spinal terminals of nociceptors. b Photographs shown are typical examples of GCaMP6s expression in DRG neurons (Scale bar 50 μm) and the presynaptic nociceptor terminals in the spinal dorsal horn (Scale bar 10 μm). c, h Typical examples, heat map and quantitative summary showing that bath application of CCL2 directly induces the calcium signals in the nociceptive DRG neurons. d, i Representative traces, heat map as well as quantitative summary showing that perfusion of CCL2 directly induces the calcium transients in the presynaptic nociceptor terminals of superficial dorsal horn. E–g and j Typical images and heat map as well as quantitative summary showing the calcium signals induced by conditioning low frequency stimulation (e), with the presence of RS504393 (f) and CCL2 (g) in the presynaptic nociceptor terminals of spinal dorsal horn. *P < 0.05, two-Way ANOVA followed by post-hoc Bonferroni test (n = 10–14). Data are expressed as mean ± SEM