Effects of Salvia injection on synaptic plasticity of neonatal rats with hypoxic-ischemic brain damage / 中华实用儿科临床杂志

ABSTRACT

Objective To observe the effects of Salvia injection on the brain pathology,expression of synaptophysin and the synaptic ultrastructure at different time points in neonatal rats after hypoxic-ischemic brain damage (HIBD).Methods One hundred and fifteen healthy newborn SD rats of 7-day-old were randomly divided into normal group,sham group,Salvia high dose group,Salvia low dose group,and the HIBD model group.The HIBD model was prepared by ligation of the left carotid artery combined with hypoxic environment.The rats(in normal group,sham and HIBD model groups) were injected with sterile saline[9.0 mL/(kg · d)],while the rats in high and low dose groups were injected with Salvia injection [9.0 mL/(kg · d) and 4.5 mL/(kg · d) respectively].The intraperitoneal injec tion lasted for 7 and 14 days.The rats' brains were collected at one day,7 days and 14 days after the modeling respec tively.The specimens of brain tissue were observed through hematoxylin-eosin (HE),the expression of synaptophysin (SYP) was determined by using immunohistochemistry method,and the synaptic ultrastructure in the frontal cortex was observed through transmission electron microscope.Results Finally,106 newborn rats were included in statistics analysial.(1)General observation:after HIBD modeling,the neonatal rats were mostly in the left-lateral position,with difficulties in turning over,balance abnormalities,limb shaking and other abnormal behaviors,and the delay of eyes open with the left upper eyelid ptosis.(2) Pathology:the disordered and deep stained nerve cells,the degenerated and necrotic neurons were observed in the brain tissues of the HIBD model group.(3) Expression of synaptophysin:mean density of SYP in the HIBD model group was significantly lower than the normal group on day 1,day 7,and day 14 (P ＜0.05);the SYP expression in the Salvia intervention groups increased compared with the HIBD model group(P ＜ 0.05).(4) Synaptic ultrastructure:the incomplete structure of the frontal cortex neurons,the swelling organelle and the synaptic structure damage were observed in the HIBD rats.Compared with the HIBD model group,the neuronic and synaptic ultrastructure were improved by the intervention treatment of high and low dose Salvia injection.Conclusions The mechanism of Salvia injection in treatment of neonatal rats with HIBD may be associated with the improvement in neuronal ultrastructure and synaptic reorganization.