Module 7: Figure arterial nerves
Perivascular nerves in rat mesenteric arteries.
This segment of rat mesenteric artery was loaded with the Ca2+ indicator fluo-4. Panel A shows the nerve bundles spread over the surface of the smooth muscle layer. These nerves were visualized by focusing 1.2 μm above the level of the smooth muscle cell layer (B). The boxes in B show the location of junctional Ca2+ transients (jCaTs) in the smooth muscle cells during nerve stimulation in the presence of prazosin to inhibit activation of the α1-adrenoreceptors. Note that these muscle Ca2+ signals are located close to the white lines that indicate the nerves shown in B. When these nerves are stimulated in the absence of prazosin, α1-adrenoreceptor activation induces a global oscillatory Ca2+ signal that triggers contraction (Module 7: Figure neurogenic contraction). Reproduced from Lamont et al (2003).