Optical Measurement of Neural Activity Using Surface Plasmon Resonance

We demonstrate that surface plasmon resonance (SPR) is applicable to the optical detection of neural signals. A low-noise SPR sensor was developed as a label- and artifact-free method for the extracellular recording of neural activity. The optical responses obtained from a rat sciatic nerve were highly correlated with simultaneously recorded electrical responses. Additional studies with stimulation intensity and lidocaine further confirmed that the optically measured signals originated from neural activities.The authors acknowledge the support of the Nano- Bioelectronics and Systems Research Center of Seoul National University, which is an Engineering Research Center sponsored by the Korean Science and Engineering Foundation (R11-2000-075-01001-1). The authors also thank Hyung Chul Shin and Woo Taek Oh for their helpful advice and Inter-university Semiconductor Research Center for providing a laboratory space