New technologies for controlling neural circuit dynamics, or entering information into the nervous system, may be capable of serving in therapeutic roles for improving the health of human patients - enabling the restoration of lost senses, the control of aberrant or pathological neural dynamics, and the augmentation of neural circuit computation, through prosthetic means. Robotic neural recording methods may open up new neurosurgical and diagnostic possibilities. We are assessing the translational possibilities opened up by our technologies, exploring the safety and efficacy of optogenetic neuromodulation in multiple animal models, and also pursuing, both in our group and in collaborations with others, proofs-of- principle of new kinds of optical neural control prosthetic, as well as new kinds of neural recording diagnostic inventions. By combining observation of brain activity with real-time analysis and responsive optical neurostimulation, new kinds of "brain co-processor" may be possible which can work efficaciously with the brain to augment its computational abilities, e.g. in the context of cognitive, emotional, sensory, or motor disability. We are exploring these ideas in the context of a diversity of neural readout and neural control strategies.