A biointegrated living brain stimulator evokes specific neural signalling

Implanted brain stimulators play a crucial role in treating various neurological disorders, including Parkinson’s disease (PD), Alzheimer’s disease, epilepsy, and depression. However, none of the existing implanted brain stimulators can realize specific neuromodulation due to fundamental disparities in signal transmission between electrical signal-induced neuronal responses and neurotransmitter-evoked neural signalling in natural neural circuits, leading to persistent challenges in biosafety and therapeutic effectiveness. Inspired by the dopaminergic neural circuit, we report a biointegrated living brain stimulator (BBS) that integrates ferroelectric bioelectronics, dopaminergic cells, and a gelatin hydrogel matrix, enabling dopamine neurotransmitter-evoked neural signalling. In contrast to conventional brain stimulators, the BBS are capable of programmed secretion of physiological-level dopamine, specifically activating nigral dopamine pathways and restoring motor function in a rodent PD model. By integrating the advantages of both bioelectronics and medicine, this lifelike BBS offers a great promise for next-generation bioelectronics, medicine, and brain-machine interfaces.