A Refined Microelectrode Arrays System for Long-Term Electrophysiological Recordings in Cerebral and Retinal Organoids

Organoids provide three-dimensional (3D) models that mimic features of human physiology, enabling the study of developmental processes, disease mechanisms, and therapeutic interventions. Microelectrode arrays (MEA) allow non-invasive monitoring of the electrical activity of organoids. Nonetheless, conventional (planar) MEA are restricted to surface-level recordings and fail to capture activity within the 3D architecture of organoids. To overcome this problem, we developed a Mesh MEA platform that integrates directly within the organoid structure, preserving cellular organization while enabling stable, long-term recordings of electrical activity. We investigate the performance of the Mesh MEA for electrophysiological recordings from cerebral organoids (COs) and retinal organoids (ROs). COs and ROs were cultured using dedicated protocols and carefully transferred to the MEA platform (MultiChannel Systems) for electrophysiological recordings. After 3 weeks, COs displayed higher electrical activity on the Mesh MEA compared to planar MEA and 3D-electrode (spike) MEA. The data suggests that the scaffold Mesh MEA plays a role in preserving the electrophysiology of COs. Moreover, immunofluorescence experiments showed that COs on the Mesh MEA expressed more synapses and a more intact architecture of neuronal projections compared to planar and 3D-electrode MEAs. ROs flattened on the surface of planar and 3D-electrode MEA. However, the Mesh MEA preserved multi-structured ROs. Consequently, the amplitude of the local field potential detected was higher in Mesh MEA-cultured ROs, indicating stable, long-term access to inner retinal layers (up to 46 days). The present work demonstrates that the Mesh MEA is a more refined system for studying COs and ROs. This abstract was presented at the American Physiology Summit 2026 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.