Electron microscopy techniques employed to explore mitochondrial defects in the developing rat brain following ketamine treatment

作者：Trisha Eustaquio, Cheng Wang, Christopher K. Dugard, Nysia I. George, Fang Liu, William Slikker, Merle G. Paule, Paul C. Howard, Angel Paredes · 发表于：Experimental Cell Research · 年份：2018 · DOI：10.1016/j.yexcr.2018.10.009 · 被引用次数：39 · 研究领域：Anesthesia and Neurotoxicity Research、Intensive Care Unit Cognitive Disorders、Mitochondrial Function and Pathology

Ketamine, an FDA-approved N-methyl-D-aspartate (NMDA) receptor antagonist, is commonly used for general pediatric anesthesia. Accumulating evidence has indicated that prolonged exposure to ketamine induces widespread apoptotic cell death in the developing brains of experimental animals. Although mitochondria are known to play a pivotal role in cell death, little is known about the alterations in mitochondrial ultrastructure that occur during ketamine-induced neurotoxicity. The objective of this pilot study was to utilize classic and contemporary methods in electron microscopy to study the impact of ketamine on the structure of mitochondria in the developing rat brain. While transmission electron microscopy (TEM) was employed to comprehensively study mitochondrial inner membrane topology, serial block-face scanning electron microscopy (SBF-SEM) was used as a complementary technique to compare the overall mitochondrial morphology from a representative treated and untreated neuron. In this study, postnatal day 7 (PND-7) Sprague-Dawley rats were treated with ketamine or saline (6 subcutaneous injections × 20 mg/kg or 10 ml/kg, respectively, at 2-h intervals with a 6-h withdrawal period after the last injection, n=6 each group). Samples from the frontal cortex were harvested and analyzed using TEM or SBF-SEM. While classic TEM revealed that repeated ketamine exposure induces significant mitochondrial swelling in neurons, the newer technique of SBF-SEM confirmed the mitochondrial s...