FUNCTIONAL CHARACTERISATION OF HUMAN STEM CELL-DERIVED CORTICAL NETWORKS AND ORGANOIDS WITH CMOS HD-MEA AND CALCIUM IMAGING

Modern computing systems face fundamental limitations in energy efficiency and scalability, particularly for artificial intelligence workloads, whereas the human brain performs massively parallel information processing with remarkable energy efficiency. Understanding how information flows, adapts and is regulated in human neuronal networks is therefore critical for neuroscience and brain inspired neuromorphic computing, yet experimental access to human-specific neural network dynamics remains limited. We investigated the functional properties and plasticity mechanisms of human induced pluripotent stem cell (iPSC)-derived neuronal networks in two-dimensional (2D) and three-dimensional (3D) culture formats. In 2D cultures, we compared co-cultures of Glutamatergic excitatory neurons and GABAergic inhibitory interneurons with astrocytes derived by directed differentiation with that by transcription factor-driven forward programming, enabling interrogation of synaptic plasticity mechanisms, including long-term potentiation (LTP) at DIV 35. Network activity was recorded longitudinally on a weekly basis from DIV14 to DIV42. In 3D cultures, we examined region-specific cortical organoids generated through developmental patterning over 2-6 months to assess how increasing cytoarchitectural complexity shapes information flow and network dynamics in a circuit dependent manner over time. Neuronal networks were interfaced with high-density CMOS multi-electrode arrays (3Brain Accura HD-MEA chip with 4096 electrodes) for high resolution large-scale extracellular electrophysiological recording and stimulation, complemented by calcium imaging and optogenetic stimulation with cell-type specific AAV1-Syn1GCamp8 and AAV5-GFAP-CFP using spinning disk confocal (Crest V3). Stimulation resulted in network wide events and enabled application of synaptic potentiation stimulation protocols. Analysis revealed functional, plastic networks which are functionally affected by neuromodulator applications such as acetylcholine, dopamine and norepinephrine.