BACKGROUND Ischemic stroke is one of the leading causes of death and disability worldwide. Low-intensity transcranial ultrasound stimulation (LITUS) is a promising neuroprotective treatment for ischemic stroke. Diffusion-weighted imaging (DWI) can be highly sensitive in the detection of ischemic brain injury. Relative apparent diffusion coefficient (rADC) values can be used to evaluate the effect of LITUS on ischemic stroke. PURPOSE The aim of this study was to determine the neuroprotective effect of LITUS at different time points using endothelin-1-induced middle cerebral artery occlusion in rats as a model of ischemic stroke. METHODS Endothelin-1 (ET-1) was injected into the cerebral parenchyma near the middle cerebral artery, which induced focal, reversible, low-flow ischemia in rats. After occlusion of the middle cerebral artery for 30 min, 120 min, and 240 min, LITUS stimulation was used respectively. DWI was performed at 1, 3, 6, 12, 18, 24, 48, and 72 hours after ischemia using a 3 T scanner. The rADC values were calculated, and functional outcomes assessed using neurobehavioral scores after ischemia. Nissl staining and estimation of Na+-k+-ATPase activity were used to assess the neuropathology after completing the last Magnetic Resonance Imaging (MRI) examination. RESULTS Endothelin-1-induced occlusion of the middle cerebral artery resulted in significant dysfunction and neuronal damage in rats. Rats that received LITUS exhibited reduced damage of the affected brain tissue after cerebral ischemia. The greatest protective effect was found when LITUS stimulation occurred 30 minutes after cerebral ischemia. CONCLUSIONS Imaging, behavioral, and histological results suggested that LITUS stimulation after an ischemic stroke produced significant neuroprotective effects.

中文翻译：

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低强度经颅超声刺激对内皮素 1 诱导的大鼠大脑中动脉闭塞的神经保护作用。

背景缺血性中风是全世界死亡和残疾的主要原因之一。低强度经颅超声刺激 (LITUS) 是一种很有前景的缺血性卒中神经保护治疗方法。弥散加权成像 (DWI) 在检测缺血性脑损伤方面非常敏感。相对表观扩散系数 (rADC) 值可用于评估 LITUS 对缺血性中风的影响。目的 本研究的目的是使用内皮素 1 诱导的大鼠大脑中动脉闭塞作为缺血性中风模型，确定 LITUS 在不同时间点的神经保护作用。方法将内皮素1（ET-1）注射到靠近大脑中动脉的脑实质内，引起大鼠局灶性、可逆性、低流量缺血。大脑中动脉闭塞30分钟后，120 分钟和 240 分钟，分别使用 LITUS 刺激。在缺血后 1、3、6、12、18、24、48 和 72 小时使用 3 T 扫描仪进行 DWI。计算 rADC 值，并使用缺血后的神经行为评分评估功能结果。在完成最后一次磁共振成像 (MRI) 检查后，使用 Nissl 染色和估计 Na+-k+-ATPase 活性来评估神经病理学。结果 Endothelin-1 诱导的大脑中动脉闭塞导致大鼠显着的功能障碍和神经元损伤。接受 LITUS 的大鼠在脑缺血后表现出受影响的脑组织的损伤减少。当 LITUS 刺激发生在脑缺血后 30 分钟时，发现了最大的保护作用。结论 影像学、行为学、