Abstracts

Rationale: Optical Recording of Intrinsic signal (ORIS) has become an important tool in exploring brain organization, neurovascular coupling mechanisms and brain diseases such as stroke and epilepsy because of its high spatiotemporal resolution and wide spatial sampling. However, the application of ORIS in human subjects has been limited to short recording sessions during neurosurgical procedures with relatively low signal-to-noise (SNR). In order to overcome the limitation of the operation room, we developed a high frequency surface mounted optical recording system (HFSMOR). Methods: We used a thin surface-mount LED and photodetector assembled on a flexible circuit board, allowing a 1mm thickness, which could be potential implanted underneath the dura. We tested the HFSMOR in a rat neocortical seizure model. Synchronous 1000 Hz illumination and recording were employed to eliminate the noise from other frequencies. The recorded signals were integrated over 30ms to further increase the signal to noise ratio (SNR). Results: We compared the HFSMOR method with the traditional suspended-camera method. The HFSMOR method achieved a SNR >10, allowing single trail resolution, while the traditional method had an SNR < 2. Conclusions: The next steps in our current study are to apply the HFSMOR method in the clinic to help treat brain diseases such as epilepsy and stroke.