Characterization of Intrinsic Optical Signal during Spreading DepolarizationAuthor(s): Zelong Zheng, Zhikai Cao, Jinbiao Luo, Jianping Lv
Spreading depolarization (SD) is a transient wave of near-complete neuronal and glial depolarization related to massive transmembrane ionic and water shifts. It spreads slowly at a rate of millimeters per minute in the central nervous system. Although mechanisms of SD initiation and propagation are still debate, abundant experimental and clinical evidence has demonstrated that SD emerges as the mechanism of migraine aura and secondary brain injury after subarachnoid hemorrhage, traumatic brain injury, and ischemic stroke. Therefore, it is essential to detect SD in animals and human with appropriate methods. Optical imaging of intrinsic signals (OIS) is a functional brain imaging technique with high spatial-temporal resolution and it is suitable for studying SD. In OIS, information about changes in cell swelling, cerebral blood volume, and oxygenated and deoxygenated hemoglobin following SD can be acquired. Moreover, OIS provides information in spatial and temporal patterns of SD. In this article, we will review studies in which OIS is used to record SD and summarize the characteristics of OIS responses to SD. Moreover, challenges for OIS will be discussed.