 Nanoelectronics and brain science.The development of nanoelectronics-enabled cellular tools underpins Lieber's views on transforming electrical recording and modulation of neuronal activity in brain science.Examples of this work include the integration of arrays of nanowire transistors with neurons at the scale that the brain is wired biologically, mapping functional activity in acute brain slices with high spatiotemporal resolution and a 3D structure capable of interfacing with complex neural networks.