Conformable, Expandable Neural Interface Device for the developing brain

PROJECT SUMMARY/ABSTRACT A major obstacle to identifying neural network mechanisms responsible for emergence of cognitive function is insufficient capability to acquire large-scale electrophysiologic signals across the course of brain maturation. There is urgent need to develop the technology and experimental protocols to acquire large-scale, chronic neu- rophysiological signals from small, fragile, immature brains via minimally invasive implantable devices. Our long-term goal is to enable such minimally invasive recording and manipulation of large-scale neural networks in developing organisms across critical developmental timeframes. Our overall objective is to establish a neural interface device that can be fully implanted in a mouse pup and can accommodate tissue growth, enabling chronic neurophysiological recording of multiple cortical regions without disrupting the environmental experi- ences required for normal development. Our central hypothesis is that integrating conducting polymer elec- trodes, expandable substrates, and conformable ionic circuits will allow creation of a Conformable, Expandable Neural Interface for the Developing Brain (CENID) that will help us elucidate the coordination of neural activity as the brain grows and matures. This hypothesis was formulated on the basis of preliminary data suggesting that organic electronics can efficiently acquire and process neurophysiologic signals. The rationale for the pro- posed research is that integration of these materials and device components enable our device to acquire data that was previously inaccessible. In order to achieve our objectives, we pursue the following two specific aims: (i) establish expandable, conformable and biocompatible integrated components for high spatiotemporal reso- lution signal acquisition and transmission of the developing brain; (ii) perform in vivo chronic implantation of CENID capable of acquiring and transmitting neurophysiological signals in freely moving mouse pups across maturation. The proposed research is innovative, in our opinion, because it substantially departs from the sta- tus quo of metal-based electrodes and silicon-based electronics by using conformable, fully biocompatible, conducting polymer-based components to create a fully implantable neural interface device compatible with monitoring large-scale cortical networks across development in naturally behaving rodents. This work is ex- pected to be significant because it will provide the groundwork for monitoring of neural networks across time periods associated with brain maturation and emergence of complex brain functions. It will have positive im- pact on development of previous unattainable experimental paradigms and contribute more broadly to im- provement in design of safe, long-term, minimally invasive bioelectronic devices.