Fig. 4: Electrophysiological recordings of brain organoids using CAMEOs.

a Schematic of the experimental protocol and recording timeline. Schematic created in BioRender. Mishra, N. (2026) https://BioRender.com/7mcqta8. b Representative filtered voltage traces from individual CAMEO channels and overlaid spike waveforms. Scale bars: 100 s (horizontal) and 100 µV (vertical) for traces; 1 ms (horizontal) and 20 µV (vertical) for waveforms. c Pharmacological modulation of activity with 20 µM glutamate. Left: raster plot representation from the same organoid. Right: comparison between spontaneous and glutamate-stimulated firing rates (n = 48 channels from 4 organoids). Statistical significance was assessed using a Mann–Whitney U test (P = 1.43 × 10⁻⁶). Scale bar: 100 s. Data are presented as mean ± SD. d Schematic comparison of neurotypical and Angelman syndrome (AS) chromosomes showing paternal (P) and maternal (M) alleles, with corresponding spike amplitude distributions in neurotypical controls and AS iPSC-derived organoids (Imprinting Centre Defect [ICD] and Uniparental Disomy [UPD] genotypes). Recordings performed at day 170 (34 organoids in experiment). Statistical significance was assessed using a Mann–Whitney U test (P = 0.0261). Schematic created in BioRender. Mishra, N. (2026) https://BioRender.com/lba01cf. e Scatter plot of spike amplitudes across all organoids measured (74 organoids).