Department of Medical Neuroscience, Faculty of Medicine and Brain Repair Centre, Dalhousie University, Halifax, NS B3H 4H7, Canada.
Department of Basic Medical Sciences, Faculty of Medicine, Al-Balqa Applied University, Al-Salt 19110, Jordan.
Int J Mol Sci. 2021 Oct 28;22(21):11642. doi: 10.3390/ijms222111642.
Traumatic brain injury (TBI) is the leading cause of death in young individuals, and is a major health concern that often leads to long-lasting complications. However, the electrophysiological events that occur immediately after traumatic brain injury, and may underlie impact outcomes, have not been fully elucidated. To investigate the electrophysiological events that immediately follow traumatic brain injury, a weight-drop model of traumatic brain injury was used in rats pre-implanted with epidural and intracerebral electrodes. Electrophysiological (near-direct current) recordings and simultaneous alternating current recordings of brain activity were started within seconds following impact. Cortical spreading depolarization (SD) and SD-induced spreading depression occurred in approximately 50% of mild and severe impacts. SD was recorded within three minutes after injury in either one or both brain hemispheres. Electrographic seizures were rare. While both TBI- and electrically induced SDs resulted in elevated oxidative stress, TBI-exposed brains showed a reduced antioxidant defense. In severe TBI, brainstem SD could be recorded in addition to cortical SD, but this did not lead to the death of the animals. Severe impact, however, led to immediate death in 24% of animals, and was electrocorticographically characterized by non-spreading depression (NSD) of activity followed by terminal SD in both cortex and brainstem.
创伤性脑损伤 (TBI) 是导致年轻人死亡的主要原因，也是一个重大的健康问题，常常导致长期并发症。然而，创伤性脑损伤后立即发生的电生理事件，可能是影响结果的基础，尚未得到充分阐明。为了研究创伤性脑损伤后立即发生的电生理事件，使用预先植入硬膜外和颅内电极的大鼠进行了落体模型创伤性脑损伤实验。在冲击后几秒钟内开始进行电生理（近直流）记录和脑活动的同时交流记录。大约 50%的轻度和重度冲击会发生皮质扩散性抑制 (SD) 和 SD 诱导的扩散性抑制。SD 在损伤后 3 分钟内在一个或两个大脑半球内被记录到。电癫痫发作很少见。虽然 TBI 和电诱导的 SD 都会导致氧化应激升高，但 TBI 暴露的大脑显示抗氧化防御能力降低。在严重的 TBI 中，除了皮质 SD 之外，还可以记录到脑干 SD，但这不会导致动物死亡。然而，严重的冲击会导致 24%的动物立即死亡，并且电皮质图特征是非扩散性抑制 (NSD) 的活动，随后在皮质和脑干中出现终末 SD。
