Responsive modulation of neural networks is increasingly being used to treat patients with auditory-neurological disorders and neuropsychiatric diseases. Yet, current technology burdens neurostimulation tools with bulky, non-biocompatible electrical components that require rigid encapsulation for long-term implantation in body. Recently, we created a novel transistor architecture (internal ion-gated organic electrochemical transistors; IGT) that can be an efficient building block for integrated bioelectronics. These transistors include all the key features required for safe, efficient, and prolonged use of transistors in biological environments: i) they are made out of biocompatible and stable materials; ii) they are soft and conformable; iii) they show high speed and amplification to detect potentially low-amplitude ionic signals of the body; iv) they can perform certain computations. Based on this emerging technology, I propose to design, develop and test novel fully implantable, contained and responsive neural interface devices that will allow long-term acquisition and closed-loop manipulation of neural circuits with high spatiotemporal resolution over extended period of time.