Correction of β3 integrin haplo-insufficiency by CRISPRa normalizes cortical network activity

The extracellular matrix (ECM) plays an essential role in regulating the function of neuronal networks. In many cell types, the ECM exerts its effects through the transmembrane receptors integrins. Here, we investigate whether neuronal integrins regulate network excitability. Specifically, we focus on {beta}3 integrin, which has been associated to autism spectrum disorder and whose expression in neurons is regulated by activity. We have designed CRISPRa tools to titrate {beta}3 integrin expression in neurons. By using multi-electrode arrays and Ca2+imaging, we show that {beta}3 integrin boosts network excitability and synchrony in primary cortical neurons. Crucially, CRISPRa could compensate precisely for {beta}3 integrin haplo-insufficiency, thereby rebalancing level and correlation of neuronal activity. By contrast, rescue strategies based on exogenous gene expression resulted in hyper-active networks firing in unison. Thus, regulation of {beta}3 integrin by CRISPRa provides a precise and efficient system for modulating neuronal network function.