 The human brain organoid system described here is a powerful tool for studying Parkinson's disease and other neurological disorders. It contains all the necessary components of the midbrain, including dopamine-producing neurons, glial cells, and myelinated axons. Additionally, it exhibits electrical activity and synaptic connections, making it a valuable model for researchers. This system could be used to develop new treatments for Parkinson's disease and other neurological conditions. This article was authored by Anna S. Monzel, Lisa M. Schmitz, Catherine Hemmer, and others.