Quantification of sympathetic hyperinnervation and denervation after myocardial infarction by three-dimensional assessment of the cardiac sympathetic network in cleared transparent murine hearts
Fig 4
Three-dimensional (3D) imaging of sympathetic nerves and coronary vessels in the post-myocardial infarction (MI) mouse heart.
(A) Three-D image of the heart 2 weeks after inducing MI. Heart samples are immunostained with tyrosine hydroxylase (green) and α-smooth muscle actin (red). Sympathetic nerves are abruptly extinguished at the site of the ligation. Arrowheads indicate the left anterior descending coronary artery. The dashed line indicates the site of ligation. The right panel shows a higher magnified view of the boxed region in the left panel. Images are obtained with a light-sheet microscope (Lightsheet Z.1, Carl Zeiss). Scale bars represent 500 μm. (B) Three-D image of the ischemic border zone in the post-MI heart. The right panel shows a higher magnified view of the boxed region in the left panel. In the ischemic border zone proximally adjacent to the site of ligation, numerous fine nerve fibers are distributed in a disordered manner. Images are obtained with a confocal microscope (LSM 700, Carl Zeiss). Scale bars represent 200 μm (left panel) and 100 μm (right panel). (C) Analyses of sympathetic nerves in post-MI mice. The nerve volume and surface area are significantly increased in the ischemic border zone and decreased in the infarct area of post-MI hearts compared to intact mice hearts (n = 5, *p<0.05, by Steel-Dwass test). Error bars represent standard error of the mean. IBZ, ischemic border zone.