A Closed-Loop Neural Prosthesis for Restoration of Function after Traumatic Brain Injury

We successfully completed the rodent aims and demonstrated that activity-dependent stimulation (ADS) was effective even when treatment was delayed up to 3 weeks post-injury. With the one-week post-injury initiation, 4 weeks of treatment resulted in recovery of motor performance that persisted for 8 weeks, the total duration of the follow-up period. Moreover, we were able to develop a fully assembled and packaged nonhuman primate (NHP) microdevice that was small enough to be housed within a chronic, skull-affixed, primate chamber. Over a 2-week monitoring period, the NHP microdevice remained fully functional in a simulated in vivo environment with elevated humidity and temperature. Finally, we were able to demonstrate the first NHP model of controlled cortical impact (CCI) injury designed for long-term behavioral assessment. We established procedures for implantation of the NHP microdevice within a chronic chamber and for microelectrodes implantation in target cortical locations. We also demonstrated that we could perform spike-triggered stimulation reliably in a squirrel monkey. We are now in an excellent position to test the ability of ADS to enhance behavioral recovery after such injuries.