Systemic evaluation of hypoxic-ischemic brain injury in neonatal rats

The objective of the study was to evaluate the systematically rat model of neonatal hypoxic-ischemic brain damage. The right carotid arteries of 7-day-old healthy Wistar rats were ligated, and then, the rats were subjected to an environment with 8 % of oxygen. Four weeks after the birth, neurobehavioral test, water maze test, and motor-evoked potential and neuropathologic examinations were performed. The footprint analysis showed significantly larger and instable paces in the hypoxic-ischemic group (P < 0.05); the time that rats crossed the balance beam in the hypoxic-ischemic group was longer than the control group (P < 0.05). The water maze test showed that the escape latency of hypoxic-ischemic group was significantly longer than that of control group (P < 0.05). The hindlimb quadriceps compound muscle-evoked potential CMEP of rats in hypoxic-ischemic group showed that the wave amplitude was lower than that of control group (P < 0.05). HE staining showed visible periventricular leukomalacia in hypoxic-ischemic groups; disrupted nuclear membrane was detected in the IH group with transelectronmicroscopy; Immunohistochemistry: compared with control group, MBP-positive neurocytes decreased, glial fibrillary acidic protein positive neurocytes increased in the periventricular zone (P < 0.05). Carotid artery ligation combining the hypoxic chamber created a reliable and stable rat model of neonatal hypoxic-ischemic brain damage and can be used for experimental research related to management of cerebral palsy.