Neonatal sevoflurane anesthesia induces long-term memory impairment and decreases hippocampal PSD-95 expression without neuronal loss

AIM: Volatile anesthetics are widely used in the clinic, and sevoflurane is the most prevalent volatile anesthetic in pediatric anesthesia. Recent findings question the poten - tial risks of volatile anesthetics on brain devel - opment. Evidence suggests that sevoflurane may cause neuronal deficiency.This study inves - tigates the long-term effect of sevoflurane in the developing brain. MATERIALS AND METHODS: We anes - thetized 7 day-old rats for 4 h with 2.5% sevoflu - rane. A Morris water maze was used to evaluate hippocampal function 7 weeks after sevoflurane exposure. Nissl staining was performed to ana - lyze neuronal loss. PSD-95 (postsynaptic density protein-95) expression in the hippocampus was measured using a western blot. RESULTS: The exposure to 2.5% sevoflurane caused long-term deficits in hippocampal func - tion and decreased hippocampal PSD-95 expres - sion without neuronal loss. This study demon - strates that P7 rats exposed for 4 h to 2.5% sevoflurane have significant spatial learning and memory impairment 7 weeks after anesthesia. In addition, PSD-95 expression in the hippocampus decreased at P56 without neuronal loss. CONCLUSIONS: These data suggest that sevoflurane causes neurotoxicity in the develop - ing brain, which may be attributed to decreased PSD-95 in the hippocampus.