Relating optical signals induced by infrared neural stimulation to electrophysiology

Infrared neural stimulation (INS) is well characterized for the peripheral nervous system; however, translation to the central nervous system (CNS) presents a new set of challenges which require us to consider different anatomy, multiple cell types, and the physiology associated with structures in the CNS. This study represents the first attempt to translate INS to in vivo stimulation of the CNS. The results from this study show that INS generates intrinsic optical signals of similar magnitude and shape associated with well characterized mechanical stimuli. Electrophysiology analysis indicates INS evokes inhibitory responses in rat somatosensory cortex. The implications of this work could lead to neural implants which allows for single cell stimulation making it possible to design closed loop neural prosthetics.