Mini microscope is a window into live muscle tissue
New technology lets researchers see motor nerve cells and muscle fibers in action

MUSCLE TWITCH In a stroke-affected biceps brachii muscle (top), muscle fibers exhibited wiggly contractions over time (x-axis), even though the volunteer was trying to relax. Fibers in the unaffected arm (bottom) held steady, showing no involuntary contractions.
G.N. Sanchez et al/Neuron 2015