Fig. 5

Muscle grown from MND patients responded poorly to human motor axons. A Timeline for human derived MNs innervating human skeletal muscle in a microfluidic culture system. B Representative visual fields showing axons of H9 stem cell-derived motor neurons (H9 MNs) immunostained for neurofilament (NF, white arrow). C MN axons grew along the microgrooves (white arrow) to enter the muscle chamber. Direction of axonal growth is indicated by the yellow arrow. D Representative visual field from the muscle chamber, showing neurofilament (red) and SV2 (pink) positive H9 motor axons intermingled with muscle cells grown from a non-MND donor. White arrows indicate large AChR clusters (green) that were located close to NF/SV2-positive axons.  E Muscle cells sourced from an MND patient displaying small AChR clusters (green, yellow arrows) adjacent to NF/SV2 positive axons. Muscle cell nuclei in C, D were labelled with Hoechst 33,342 (blue)