The ultrastructural effects of prolonged normothermic and cold ischemia on the cerebral cortex of the adult rat were investigated. Complete cerebral ischemia was produced by cardiac arrest and the animals' temperature was maintained at 37°C for periods ranging from 0 to 81 hours before electron microscopy preparation. Electron micrographs of cold cerebral ischemia were generated after stabilizing the rat's temperature at 0°C after cardiac arrest for periods ranging from 0 hours to 6 months. A qualitative examination of the electron micrographs shows structural signatures of energy depletion such as vessel leaking and chromatin clumping after 1 hour at 37°C and after 24 hours at 0°C, followed by synapse degradation after 6 hours at 37°C and 1 week at 0°C. Evidence of advanced necrosis was observed after 36 hours at 37°C and 2 months at 0°C. A deep learning algorithm was introduced that demonstrates the temperature dependence of ischemia-induced ultrastructural changes and that can also successfully distinguish between early ischemic changes and advanced necrosis.

中文翻译：

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成年大鼠长期正常体温和冷性脑缺血的超微结构表征。

研究了长期的常温和冷缺血对成年大鼠大脑皮层的超微结构影响。在准备电子显微镜之前，通过心脏骤停产生完全的脑缺血，并将动物的体温维持在37°C，持续0至81小时。心脏骤停后0到6个月，将大鼠的温度稳定在0°C，然后生成冷脑缺血的电子显微照片。电子显微照片的定性检查显示了能量消耗的结构特征，例如在37°C下1小时后和0°C下24小时后血管渗漏和染色质结块，然后在37°C和1周后6小时后突触降解。在0°C下。在37°C下36小时和0°C下2个月后观察到晚期坏死的迹象。