Human neural organoids (NOs) provide a powerful platform for investigating synaptic development and dysfunction during early neurodevelopment. However,methodologies for isolating functional synaptic structures from these models remain limited. Here,we present a differential centrifugation protocol enabling the enrichment of growth cone particles (GCPs) and immature synaptosomes from airâ€liquid interface cerebral organoids (ALIâ€COs) at distinct developmental stages (Day 90 and 150). Notably,the method avoids density gradients,requires minimal starting material while maintaining reproducibility across human and murine tissues. Quantitative proteomic profiling revealed significant enrichment of growth cone markers (e.g.,GAP43) and classical synaptosomal proteins (e.g.,PCLO,BSN,SYN1). Transmission electron microscopy (TEM) confirmed the presence of membraneâ€enclosed GCPs with fibrous content and mitochondria in Day 90 isolates,and immature synaptosomes containing synaptic vesicles on day 150. Functional viability of both types of synaptic structures was demonstrated through KClâ€induced depolarization,which triggered phosphorylation changes in growth cone proteins (GAP43,MARCKS,MARCKSL1),cytoskeletal regulators (DCLK1,SHTN1,MARK4,MAP1B) and protein kinases (CAMK2G,PRKCE) in Day 90 GCPs,as well as classical synaptic vesicle cycle proteins (SYN1,DNM1,RPH3A) at Day 150. Overall,this study establishes a centrifugationâ€based protocol for isolating growth cones and immature synapses from human organoids,capturing key stages of synaptic development and enabling scalable,patientâ€compatible models to study synaptic function and dysfunction in neurodevelopmental and neurodegenerative disorders. Synapses are implicated in several neurological disorders and psychiatric diseases. The emergence and wide use of neural organoids provide a new opportunity to study human synapses in healthy and disease settings. Therefore,we developed a simple method for the enrichment of synaptosomes and growth cone particles from forebrain organoids. The method is based on differential centrifugation,works with small tissue amounts,and is highly reproducible. We validated the functionality of the isolated structures using KCl stimulation and phosphoproteomics. The method enables detailed mapping of protein composition and function during growth cone pathfinding,synaptogenesis,and establishment of neural circuits in organoids.
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