THE ALI-MEA: AN AIR-LIQUID INTERFACE MICROELECTRODE ARRAY DEVICE FOR LONG-TERM 3D NEURAL TISSUE FUNCTIONAL ANALYSIS AND PHARMACOLOGY TESTING

The increasing use of 3D in vitro models such as neural aggregates and brain organoids requires electrophysiological tools combining high temporal resolution with reliable oxygenation and long-term stability. However, conventional microelectrode array (MEA) devices remain limited for use with 3D tissue preparations, particularly for prolonged recordings and integrated functional assays.
We present the ALI-MEA (Fig.A,B), a microfluidic MEA device specifically designed for tissue culture at air-liquid interface (ALI), enabling stable electrophysiological recordings while preserving long-term tissue viability. It is compatible with commercially available data acquisition systems from MCS and allows electrophysiology together with microscopy, medium sampling or tissue analysis.
Using aggregated neural spheroids (Fig.C), robust long-term recordings of both action potentials and local field potentials were obtained, enabling quantitative assessment of network activity, bursting dynamics, and spatiotemporal propagation (Fig. D-G). Network connectivity was also characterized using correlation-based metrics. Functional sensitivity was validated through a bidirectional pharmacological paradigm, showing both enhancement and suppression of network activity in a robust and reversible manner, supporting the suitability of the ALI-MEA for network-level assays. Longitudinal recordings over several weeks further confirmed the stability of both signal quality (high signal-to-noise ratio) and tissue viability. Furthermore, the versatility of the ALI-MEA is presented across multiple excitable tissues, including ex vivo chicken retina with stimulus-evoked responses, human cardiac organoids and human brain organoids with pharmacological modulation.
Experimental data demonstrates that the ALI-MEA is a well-suited tool for neurodevelopmental studies, disease modeling, and preclinical pharmacology applications.