Repeated sevoflurane exposures inhibit neurogenesis by inducing the upregulation of glutamate transporter 1 in astrocytes

Sevoflurane is a widely used general anesthetic in pediatric patients. Although repeated sevoflurane exposure is known to cause neurodevelopmental disorders in children, the mechanism of this neurotoxicity remains largely unknown. Herein, we investigated the role of glutamate transporter 1(GLT1) in sevoflurane-induced decreased neurogenesis. Neonatal rat pups (postnatal day 7, PN7) were exposed to 3% sevoflurane for two hours for three consecutive days. Neuron loss and decreased neurogenesis have been observed in the neonatal rat brain, along with decreased number of astrocytes. Apoptotic astrocytes were observed after repeated sevoflurane exposure in vitro, resulting in decreased levels of brain-derived neurotrophic factor (BDNF). Calcium overload was observed in astrocytes after repeated sevoflurane exposure, in addition to upregulation of GLT1. Inhibition of GLT1 activity ameliorates repeated sevoflurane exposure-induced cognitive deficits in adult rats. Mechanically, the upregulation of GLT1 was caused by the activation of mRNA translation. RNA-sequencing analysis further confirmed that translation-related genes were activated by repeated sevoflurane exposure. These results indicate that cognitive deficits caused by repeated sevoflurane exposure during PN7-9 are triggered decreased neurogenesis. The proposed underlying mechanism involves upregulation of Apoptosis in astrocytes induced by GLT1, therefore, we propose GLT1 as a potential pharmacological target for brain injury in pediatric practice.

apoptosis; astrocytes; glutamate transporter 1; neurogenesis; sevoflurane.