OBJECTIVES: To investigate the regulatory role of astrocytes in the dorsomedial hypothalamus (DMH) during sevoflurane anesthesia emergence. METHODS: Forty-two male C57BL/6 mice were randomized into 6 groups (n=7) for assessing astrocyte activation in the dorsomedial hypothalamus (DMH) under sevoflurane anesthesia. Two groups of mice received microinjection of agfaABC1D promoter-driven AAV2 vector into the DMH for GCaMP6 overexpression, and the changes in astrocyte activity during sevoflurane or air inhalation were recorded using calcium imaging. For assessing optogenetic activation of astrocytes, another two groups of mice received microinjection of an optogenetic virus or a control vector into the DMH with optic fiber implantation, and sevoflurane anesthesia emergence was compared using behavioral experiments. In the remaining two groups, electroencephalogram (EEG) recording during sevoflurane anesthesia emergence was conducted after injection of the hChR2-expressing and control vectors. Anesthesia induction and recovery were assessed by observing the righting reflex. EEG data were recorded under 2.0% sevoflurane to calculate the burst suppression ratio (BSR) and under 1.5% sevoflurane for power spectrum analysis. Immunofluorescence staining was performed to visualize the colocalization of GFAP-positive astrocytes with viral protein signals. RESULTS: Astrocyte activity in the DMH decreased progressively as sevoflurane concentration increased. During 2.0% sevoflurane anesthesia, the mice injected with the ChR2-expressing virus exhibited a significantly shortened wake-up time (P<0.05), and optogenetic activation of the DMH astrocytes led to a marked reduction in BSR (P<0.001). Under 1.5% sevoflurane anesthesia, optogenetic activation resulted in a significant increase in EEG gamma power and a significant decrease in delta power in ChR2 group (P<0.01). CONCLUSIONS Optogenetic activation of DMH astrocytes facilitates sevoflurane anesthesia emergence but does not significantly influence anesthesia induction. These findings offer new insights into the mechanisms underlying anesthesia emergence and may provide a potential target for accelerating postoperative recovery and managing anesthesia-related complications.
Animals ; Astrocytes/physiology* ; Sevoflurane ; Mice, Inbred C57BL ; Mice ; Male ; Electroencephalography ; Anesthetics, Inhalation/pharmacology* ; Hypothalamus/cytology* ; Anesthesia Recovery Period ; Methyl Ethers/pharmacology*

Clinical researches including the Mayo Anesthesia Safety in Kids (MASK) study have found that children undergoing multiple anesthesia may have a higher risk of fine motor control difficulties. However, the underlying mechanisms remain elusive. Here, we report that erythropoietin receptor (EPOR), a microglial receptor associated with phagocytic activity, was significantly downregulated in the medial prefrontal cortex of young mice after multiple sevoflurane anesthesia exposure. Importantly, we found that the inhibited erythropoietin (EPO)/EPOR signaling axis led to microglial polarization, excessive excitatory synaptic pruning, and abnormal fine motor control skills in mice with multiple anesthesia exposure, and those above-mentioned situations were fully reversed by supplementing EPO-derived peptide ARA290 by intraperitoneal injection. Together, the microglial EPOR was identified as a key mediator regulating early synaptic development in this study, which impacted sevoflurane-induced fine motor dysfunction. Moreover, ARA290 might serve as a new treatment against neurotoxicity induced by general anesthesia in clinical practice by targeting the EPO/EPOR signaling pathway.
Animals ; Sevoflurane/toxicity* ; Microglia/drug effects* ; Anesthetics, Inhalation/adverse effects* ; Mice ; Mice, Inbred C57BL ; Receptors, Erythropoietin/metabolism* ; Neuronal Plasticity/drug effects* ; Male ; Prefrontal Cortex/drug effects* ; Erythropoietin/pharmacology* ; Signal Transduction/drug effects*

OBJECTIVE: To explore the regulatory effects of GABAergic neurons in the zona incerta (ZI) on sevoflurane and propofol anesthesia. METHODS: Forty-eight male C57BL/6J mice divided into 8 groups (n=6) were used in this study. In the study of sevoflurane anesthesia, chemogenetic experiment was performed in 2 groups of mice with injection of either adeno-associated virus carrying hM3Dq (hM3Dq group) or a virus carrying only mCherry (mCherry group). The optogenetic experiment was performed in another two groups of mice injected with an adeno-associated virus carrying ChR2 (ChR2 group) or GFP only (GFP group). The same experiments were also performed in mice for studying propofol anesthesia. Chemogenetics or optogenetics were used to induce the activation of GABAergic neurons in the ZI, and their regulatory effects on anesthesia induction and arousal with sevoflurane and propofol were observed; EEG monitoring was used to observe the changes in sevoflurane anesthesia maintenance after activation of the GABAergic neurons. RESULTS: In sevoflurane anesthesia, the induction time of anesthesia was significantly shorter in hM3Dq group than in mCherry group (P < 0.05), and also shorter in ChR2 group than in GFP group (P < 0.01), but no significant difference was found in the awakening time between the two groups in either chemogenetic or optogenetic tests. Similar results were observed in chemogenetic and optogenetic experiments with propofol (P < 0.05 or 0.01). Photogenetic activation of the GABAergic neurons in the ZI did not cause significant changes in EEG spectrum during sevoflurane anesthesia maintenance. CONCLUSION Activation of the GABAergic neurons in the ZI promotes anesthesia induction of sevoflurane and propofol but does not affect anesthesia maintenance or awakening.
Male ; Animals ; Mice ; Mice, Inbred C57BL ; Propofol/pharmacology* ; Sevoflurane/pharmacology* ; Zona Incerta ; Anesthesia, General ; GABAergic Neurons

Dopaminergic neurons in the ventral tegmental area (VTA) play an important role in cognition, emergence from anesthesia, reward, and aversion, and their projection to the cortex is a crucial part of the "bottom-up" ascending activating system. The prelimbic cortex (PrL) is one of the important projection regions of the VTA. However, the roles of dopaminergic neurons in the VTA and the VTA^DA-PrL pathway under sevoflurane anesthesia in rats remain unclear. In this study, we found that intraperitoneal injection and local microinjection of a dopamine D1 receptor agonist (Chloro-APB) into the PrL had an emergence-promoting effect on sevoflurane anesthesia in rats, while injection of a dopamine D1 receptor antagonist (SCH23390) deepened anesthesia. The results of chemogenetics combined with microinjection and optogenetics showed that activating the VTA^DA-PrL pathway prolonged the induction time and shortened the emergence time of anesthesia. These results demonstrate that the dopaminergic system in the VTA has an emergence-promoting effect and that the bottom-up VTA^DA-PrL pathway facilitates emergence from sevoflurane anesthesia.
Anesthesia ; Animals ; Dopaminergic Neurons/metabolism* ; Rats ; Receptors, Dopamine D1/metabolism* ; Sevoflurane/pharmacology* ; Ventral Tegmental Area/metabolism*

A growing number of studies have identified sex differences in response to general anesthesia; however, the underlying neural mechanisms are unclear. The medial preoptic area (MPA), an important sexually dimorphic structure and a critical hub for regulating consciousness transition, is enriched with estrogen receptor alpha (ERα), particularly in neuronal clusters that participate in regulating sleep. We found that male mice were more sensitive to sevoflurane. Pharmacological inhibition of ERα in the MPA abolished the sex differences in sevoflurane anesthesia, in particular by extending the induction time and facilitating emergence in males but not in females. Suppression of ERα in vitro inhibited GABAergic and glutamatergic neurons of the MPA in males but not in females. Furthermore, ERα knockdown in GABAergic neurons of the male MPA was sufficient to eliminate sex differences during sevoflurane anesthesia. Collectively, MPA ERα positively regulates the activity of MPA GABAergic neurons in males but not in females, which contributes to the sex difference of mice in sevoflurane anesthesia.
Anesthesia ; Animals ; Estrogen Receptor alpha/metabolism* ; Female ; Male ; Mice ; Preoptic Area ; Sevoflurane/pharmacology* ; Sex Characteristics

Objective To explore the effect of dexmedetomidine(Dex)on sevoflurane-induced cognitive impairment in neonatal rats through Wnt signaling pathway. Methods Sixty 7-day-old SD rats were assigned into five groups:control group(without any intervention),Dex group(intraperitoneal injection of 25 μg/kg Dex),sevoflurane group(3% sevoflurane treatment for 4 hours),sevoflurane+Dex group(inhalation of 3% sevoflurane after injection of 25 μg/kg Dex for 4 hours),and sevoflurane+Dex+Wnt inhibitor group(Wnt inhibitor XAV393 and 25 μg/kg Dex were injected and 3% sevoflurane was inhaled for 4 hours).Three weeks later,Morris water maze was used to detect the cognitive function;TdT-mediated dUTP nick end labeling(TUNEL)staining was performed to detect the apoptosis of hippocampal neurons;neuronal nuclei (NeuN) staining was conducted to detect the survival of hippocampal neurons;Western blot was carried out to detect the expression of apoptosis-related proteins.The expression of the factors involved in Wnt/GSK-3β/β-catenin signaling pathway was detected by fluorescence quantitative polymerase chain reaction,and Western blot. Results Compared with the control group,there was no significant difference in the escape latency of Dex group(t=0.304,P=0.768);the escape latency in sevoflurane group(t=5.823,P=0.002),sevoflurane+Dex group(t=3.188,P=0.010),and sevoflurane+Dex+Wnt inhibitor group(t=5.784,P=0.002)was significantly prolonged.Compared with that in the sevoflurane group,the escape latency in sevoflurane+Dex group(t=3.646,P=0.005)was significantly shortened.Compared with that in sevoflurane+Dex group,the escape latency in sevoflurane+Dex+Wnt inhibitor group(t=3.296,P=0.008)was prolonged.Compared with that in the control group,the times of crossing platform in sevoflurane group(t=5.179, P=0.004),sevoflurane+Dex group(t=2.309,P=0.043),and sevoflurane+Dex+Wnt inhibitor group(t=3.871, P=0.003)decreased.Compared with that in sevoflurane group,the times of crossing platform in sevoflurane+Dex group(t=3.296,P=0.008)significantly increased.Compared with that in sevoflurane+Dex group,the times of crossing platform in sevoflurane+Dex+Wnt inhibitor group(t=2.361, P=0.041)reduced.Compared with the control group,there was no significant difference in the number of apoptotic cells in Dex group(t=1.920,P=0.127),and the number of apoptotic cells in sevoflurane group,sevoflurane+Dex group,and sevoflurane+Dex+Wnt inhibitor group increased by 16%(t=13.436,P=0.002),5%(t=7.752, P=0.001),and 11.5%(t=12.612,P=0.002),respectively.Compared with that in the sevoflurane group,the number of apoptotic cells in sevoflurane+Dex group and sevoflurane+Dex+Wnt inhibitor group decreased by 11%(t=8.521,P=0.002)and 5.5%(t=3.123,P=0.036),respectively.Compared with that in the sevoflurane+Dex group,the number of apoptotic cells in sevoflurane+Dex+Wnt inhibitor group increased by 6.5%(t=6.250,P=0.003).Compared with that in the control group,the number of positive cells in 0.15 mm
Animals ; Animals, Newborn ; Cognitive Dysfunction/chemically induced* ; Dexmedetomidine/pharmacology* ; Glycogen Synthase Kinase 3 beta ; Rats ; Rats, Sprague-Dawley ; Sevoflurane/toxicity* ; Wnt Signaling Pathway ; beta Catenin/metabolism*

BACKGROUND: Sevoflurane is widely used to anesthetize children because of its rapid action with minimal irritation of the airways. However, there is a high risk of agitation after emergence from anesthesia. Strabismus surgery, in particular, can trigger agitation because patients have their eyes covered in the postoperative period. The aim of this study was to determine whether or not esmolol and lidocaine could decrease emergence agitation in children. METHODS: Eighty-four patients aged 3 to 9 years undergoing strabismus surgery were randomly assigned to a control group (saline only), a group that received intravenous lidocaine 1.5 mg/kg, and a group that received intravenous esmolol 0.5 mg/kg and lidocaine 1.5 mg/kg. Agitation was measured using the objective pain score, Cole 5-point score, and Richmond Agitation Sedation Scale score at the end of surgery, on arrival in the recovery room, and 10 and 30 min after arrival. RESULTS: The group that received the combination of esmolol and lidocaine showed lower OPS and RASS scores than the other two groups when patients awoke from anesthesia (OPS = 0 (0-4), RASS = -4 [(-5)-1]) and were transferred to the recovery room (OPS = 0 (0-8), RASS = -1 [(-5)-3]) (P < 0.05). There was no significant difference in the severity of agitation among the three groups at other time points (P > 0.05). CONCLUSIONS: When pediatric strabismus surgery is accompanied by sevoflurane anesthesia, an intravenous injection of esmolol and lidocaine could alleviate agitation until arrival in the recovery room. TRIAL REGISTRATION Clinical Research Information Service, No. KCT0002925; https://cris.nih.go.kr/cris/en/search/search_result_st01.jsp?seq=11532.
Anesthesia ; methods ; Child ; Child, Preschool ; Double-Blind Method ; Humans ; Injections, Intravenous ; Lidocaine ; administration & dosage ; pharmacology ; Propanolamines ; administration & dosage ; pharmacology ; Sevoflurane ; therapeutic use ; Strabismus ; surgery ; Wakefulness ; drug effects

OBJECTIVE: To explore the delayed neuroprotective effect of sevoflurane on the expression of NF-kappaB in rat models of transient focal ischemia-reperfusion. METHODS: Adult male Sprague-Dawley rats (220 approximately 300 g) were randomly assigned into 3 groups:an ischemia-reperfusion (I/R) group, and a 2.5% Sevoflurane (Sevo1) group, and a 4.0% sevoflurane (Sevo2) group. All the rats were subjected to right middle cerebral artery occlusion (MCAO) for 2 hours. The rats in the I/R group were exposed to pure oxygen 60 min at 24 h before MCAO. Sevoflurane preconditioning was induced 24 h before brain ischemia by exposing the rats to 2.5% or 4.0% sevoflurane + oxygen for 60 min. The effects of sevoflurane on the brain was analyzed by evaluating the infarct volume and the expression of NF-kappaB protein through 2, 3, 5-triphenyltetrazolium chloride (TTC) staining and immunohistochemistry at 24 and 72 h after the reperfusion. RESULTS: The infarct volumes were significantly reduced in the Sevo1 and Sevo2 groups at 24 and 72 h after the reperfusion, compared with the I/R group. The expression of NF-kappaB in the ischemic territory increased after cerebral ischemia, sevoflurane could remarkably decrease the expression of NF-kappaB in 24 and 72 h after the reperfusion. CONCLUSION Sevoflurane inhibits the expression of NF-kappaB protein during focal ischemia the reperfusion,which may be part of the mechanism of its delayed neuroprotective function.
Animals ; Ischemic Attack, Transient ; drug therapy ; metabolism ; Male ; Methyl Ethers ; pharmacology ; therapeutic use ; NF-kappa B ; genetics ; metabolism ; Neuroprotective Agents ; pharmacology ; therapeutic use ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; metabolism ; prevention & control ; Sevoflurane

OBJECTIVE: To investigate whether the reactive oxygen species (ROS) and mitochondrial ATP-sensitive potassium (mitoKATP) channels were involved in delayed neuroprotection induced by sevoflurane on tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) levels. METHODS: Eighty-four male SD rats weighing 250 approximately 280 g, undergoing thread embolism of the right middle cerebral artery occlusion (MCAO) to cause focal ischemia for 2 h and then undergoing 24 h reperfusion, were randomly divided into 7 groups (n=12, each): a sham group(S), an ischemia-reperfusion group (I/R), a sevoflurane preconditioning group (Sevo), a 2-mercaptopropionylglycine (ROS scavenger)+sevoflurane group (MPG+Sevo), a 5-hydroxydecanoate (a mitoK(ATP) blocker) + sevoflurane group (5-HD+Sevo), an MPG group, and a 5-HD group. The protein level of TNF-alpha and IL-1beta in the cerebral issue was detected by enzyme linked immunosorbent assay (ELISA) and the expression of mRNA was measured by semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR). RESULTS: Apoptosis index (AI), the protein level and the mRNA expression of TNF-alpha and IL-1beta were significantly higher in the I/R group than those of Group S. Pre-administration of sevoflurane could inhibit the increase of the protein level and the expression of mRNA of TNF-alpha, and IL-1beta and attenuate the cerebral damage induced by ischemia-reperfusion. Neuroprotection of sevoflurane preconditioning was abolished by MPG and 5-HD. However, MPG and 5-HD alone had no effect. CONCLUSION Sevoflurane can produce delayed protection against cerebral ischemia-reperfusion injury by down-regulating TNF-alpha, IL-1beta protein, and mRNA expression.
Animals ; Hypoxia-Ischemia, Brain ; complications ; drug therapy ; Infarction, Middle Cerebral Artery ; complications ; drug therapy ; Interleukin-1beta ; genetics ; metabolism ; Ischemic Preconditioning ; methods ; KATP Channels ; metabolism ; Male ; Methyl Ethers ; pharmacology ; therapeutic use ; Neuroprotective Agents ; pharmacology ; therapeutic use ; RNA, Messenger ; genetics ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Reactive Oxygen Species ; metabolism ; Reperfusion Injury ; etiology ; prevention & control ; Sevoflurane ; Tumor Necrosis Factor-alpha ; genetics ; metabolism