Hereditary motor neuropathies, such as Lou Gehrig’s disease, are a collection of disorders that cause damage to motor neurons and impair their capacity to deliver signals to the musculature. Many of these conditions specifically lead to breakdown of the neuromuscular junction; the connection linking spinal cord motor neurons to muscles. Currently, there are no accurate human models of the neuromuscular junction, which makes assessing the development and breakdown of these structures in disease states difficult. This project aims to establish a screening system for neuromuscular junction functionality. We will use human stem cell-derived motor neurons and muscle cells, and grow them within a compartmentalized chamber designed to control how the two cell types interact. Underlying electrodes will be used to measure electrical signals between neurons and muscle cells in this system, to determine the level of communication between the two cell types. This tool will be of immense value to ISCRM researchers seeking to control cell-cell interactions and gauge the severity of communication breakdown in stem cell-based models of neuropathic disease.