Petersilie et al. 2023 - Figure 1

Brain organoids derived from human pluripotent stem cells (hPSCs) are a promising tool for studying human neurodevelopment and related disorders. Here, we generated long-term cultures of cortical brain organoid slices (cBOS) grown at the air-liquid interphase from regionalized cortical organoids. We demonstrate that cBOS host mature neurons and astrocytes organized in complex architecture. By leveraging the fact that cBOS allow direct access to the developing neural cells, we carried out an array of functional analyses. Whole-cell patch-clamp demonstrated subthreshold synaptic inputs and action potential firing of neurons. Spontaneous intracellular calcium signals turned into synchronous large-scale calcium oscillations upon combined disinhibition of NMDA receptors and blocking of GABAA receptors. Lastly, FRET-based imaging with the genetically-encoded nanosensor ATeam1.03YEMK revealed the high sensitivity of neurons to acute metabolic inhibition. Altogether, cBOS represent a powerful platform for assessing the morphological and functional aspects of organized human neural cells in intact minimal networks.