Effects of sevoflurane on learning, memory, and expression of pERK1/2 in hippocampus in neonatal rats

Abstract

Background: Sevoflurane may be associated with neural toxicity in the developing brain, but the mechanism is still unclear. Phosphorylated extracellular signal-regulated kinases 1/2 (pERK1/2) are important for developing neurons. The aim of our study was to investigate the effects of sevoflurane on spatial learning and memory and on expression of pERK1/2 in hippocampus of neonatal rats.

Methods: Sixty-three neonatal rats were randomly divided into three groups: control group, sevoflurane (sevo) group, and sham group. Rats in the control group were placed in a plastic chamber flushed continuously for 4 h with air alone, rats in the sevo group were exposed in 5% sevoflurane and air for 4 h, and rats in the sham group were exposed in 5% carbon dioxide and air for 4 h, with identical flow rates for all groups. All three groups were subjected to Morris water maze test 1 day after sevoflurane exposure. Moreover, expression of pERK1/2 was determined by immunochemistry and Western blot at 1, 3, and 6 weeks after exposure.

Results: Compared with the control group, the escape latency was longer in sevo group and the expression of pERK1/2 was significantly inhibited in the sevo group (P < 0.01); no differences between control and sham groups were observed.

Conclusion: Our study demonstrated that neonatal rats exposed to sevoflurane had impaired spatial learning and memory, and this may be attributed to decreased pERK1/2 in the hippocampus.