The U.S. Food and Drug Administration (FDA) recently issued a safety warning, stating that anesthesia in the early stages of life stimulates the normal development of the brain. The latest study published in the PLOS Biology Journal by Eunchai Kang et al. found that exposure to isoflurane in early mice can cause abnormal activation of mTOR signals, which affects the brain. Researchers at Johns Hope University conducted an analysis of the mouse hippocampus, which is a brain structure involved in learning and memory.
Since many hippocampal neurons develop early in life, premature exposure to anesthetics will affect their normal development. The author gave a clinical dose of isoflurane to 15-day-old mice and recorded the development of the hippocampus. The results showed that the development of hippocampal neuron types was significantly affected. Notably, the synapses of these neurons doubled the length of the control mice. This indicates that anesthesia treatment can cause abnormal growth of neurons. In addition, the authors also found that anesthesia treatment significantly reduced the number of spinous processes on the synaptic surface of mature neurons.
Changes In order to study whether these changes affect the learning ability of mice, the authors conducted two standard behavioral tests on different groups of mice. The results showed that the learning and behavioral abilities of mice treated with isoflurane were significantly reduced.
Later, the authors discovered that drugs that inhibit the mTOR signaling pathway can prevent abnormal development of mouse cranial neurons. This discovery may help change the clinical application of infant anesthetics and help develop drugs for this adverse effect.