Microplastics induce cellular senescence and alter network activity in human brain organoids

In a preprint study, researchers exposed human brain organoids to environmentally relevant microplastics and nanoplastics. The team tested synthetic plastics, including polystyrene, polyethylene terephthalate, and polyethylene, alongside ocean-derived particles collected from Hawaii. The exposures triggered innate immune transcriptional programs, a robust neuroinflammatory response, and activation of senescence-associated secretory phenotype pathways. Plastic particles also disrupted developmental trajectories, impairing neuroectodermal differentiation and skewing lineage commitment toward mesoderm-like and choroid plexus-like populations. Furthermore, the exposures caused a marked imbalance in neuronal and glial differentiation. High-density multielectrode array recordings demonstrated that these molecular changes altered electrophysiological activity and impaired neuronal network dynamics. These results indicate that plastic accumulation induces cellular senescence, inflammation, and functional neurophysiological disruptions in human brain tissues.