Establishment of hypoxic-ischemic brain injury model in newborn mice

  Objective: To improve the classic Vannucci method and establish a simple and stable neonatal mouse model of hypoxic-ischemic brain injury. Methods: The 11-day-old KM mice were divided into normal control group (N group, n=20) and ischemia-hypoxic group (HIBD group, n=160). The left common carotid artery was ligated in the HIBD group, respectively. Model hypoxia according to C1-C8 conditions. After modeling, the most stable modeling conditions were selected by comparing the mortality of mice under each condition, the success rate of modeling, and the volume of TTC stained cerebral infarction. After modeling, the body weight growth curve was used to analyze the growth and development of mice; Longa, Grip test, and suspension test were used to evaluate the neuromotor function of mice; HE staining was used to observe the pathological changes of brain tissue. Results: Newborn mice underwent ligation of the left common carotid artery, hypoxia for 45 minutes at 8% O2 and 35°C, low mortality (8.3%) and high modelling rate (47.92%); HIBD group compared with N group mice Slow weight gain and severe neuromotor dysfunction; cerebral infarction area on the ligation side, accounting for about (17.76±0.70)% of the total brain volume; degeneration and necrosis of neurons in the cerebral cortex and hippocampus on the ligation side.

  Conclusion: In this experiment, neonatal mice were used for ligation of the left common carotid artery. The HIBD animal model was replicated under 8% O2 and 35°C hypoxia for 45 minutes. It is simple and stable. It is suitable for neonatal ischemia and hypoxia. An ideal animal model for brain injury research.