Figure 4. The effects of TTX and carbachol on USMC Ca²⁺ transients.

Aa and b, representative ST maps of Ca²⁺ transient firing within a single USMC recorded in situ during control conditions (a) and after incubation with 1 μm TTX (b). Ba–d, summary data showing the effect of 1 μm TTX on USMC Ca²⁺ transient frequency (a), amplitude (b), duration (c) and spatial spread (d) (c = 18, n = 6). C, relative expression of cellular identification genes in FACS sorted and unsorted urethral cells from SMC‐eGFP mice determined by qPCR analysis, normalized to Gapdh expression (n = 4). Genes examined are Kit (tyrosine kinase receptor, found in interstitial cells of Cajal), Pdgfra found in PDGFRα⁺ interstitial cells, Myh11 (smooth muscle myosin), Uch11 (neural marker encoding PGP 9.5) and Tpsab1 (mast cell tryptase). D, relative expression of muscarinic receptor genes in FACS sorted and unsorted urethral cells from SMC‐eGFP mice determined by qPCR analysis, normalized to Gapdh expression (n = 4). Ea and b, representative ST maps of Ca²⁺ transient firing within a single USMC recorded in situ during control conditions (a) and after incubation with 10 μm CCh (b). Fa–d, summary data showing the effect of 10 μm CCh on USMC Ca²⁺ transient frequency (a), amplitude (b), duration (c) and spatial spread (d) (c = 13, n = 4). ns, not significant.