Objective:To evaluate the relationship between the mechanism of ω-3 polyunsaturated fatty acids (ω-3 PUFAs) in preventing brain neurotoxicity caused by multiple sevoflurane anesthesia and peroxisome proliferator-activated receptor gamma (PPARγ)/peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α) signaling pathway in neonatal mice.Methods:This study was performed in 2 parts. Part Ⅰ Using a random number table method, 6 C57BL/6 pregnant mice were assigned to receive a standard diet, 3 pregnant mice were assigned to receive a diet supplemented with fish oil from day 2 of gestation to day 14 after parturition (ω-3 PUFAs 300 mg were added to every 20 g of conventional diet). Healthy C57BL/6 mice of both sexes, aged 6 days, weighing 3-5 g, were selected after parturition. Seventeen neonatal pups from 3 pregnant mice that were fed a conventional diet were assigned to control group (C group), 17 neonatal pups from 3 pregnant mice that were fed a conventional diet were assigned to sevoflurane group (S group), and 17 neonatal pups from pregnant mice that were fed a diet supplemented with fish oil were assigned to ω-3 PUFAs plus sevoflurane group (PS1 group) using the random number table method. Part Ⅱ Four C57BL/6 pregnant mice were assigned to receive a diet supplemented with fish oil from day 2 of gestation to day 14 after parturition. After parturition, 12 neonatal pups from 2 pregnant mice that were fed a diet supplemented with fish oil were assigned to ω-3 PUFAs plus sevoflurane group (PS2 group), and 12 neonatal pups from 2 pregnant mice that were fed a diet supplemented with fish oil were assigned to ω-3 PUFAs plus PPARγ inhibitor GW9662 plus sevoflurane group (PGS group) using a random number table method. GW9662 (2 mg/kg) was intraperitoneally injected at 30 min before exposure to sevoflurane in PGS group. All offspring mice were breastfed until 21 days of age, after which they were housed separately from the mother and allowed ad libitum access to a conventional diet. S, PS1, PS2 and PGS groups inhaled 3% sevoflurane in 40% oxygen for 2 h daily on postnatal days 6, 7 and 8. C group inhaled only 40% oxygen instead. Y maze test was performed on days 33 after birth. The rotarod test was performed on day 35 after birth. After the behavioral testing, the expression of PPARγ, PGC1α, mitofusin-1 (MFN1), MFN2, dynamin-related protein 1 (DRP1), interleukin-6 (IL-6), interleukin-1 β (IL-1 β), and tumor necrosis factor-α (TNF-α) was detected by Western blot, the ultrastructure of mitochondria in hippocampal neurons was observed with a transmission electron microscope, and the mitochondrial membrane potential (MMP), level of reactive oxygen species (ROS) and content of ATP were determined.Results:Part Ⅰ Compared with C group, the time of stay at the new-arm and time spent on the rotarod were significantly shortened, the percentage of movement distance in the new-arm was decreased, the expression of PPARγ, PGC1α, MFN1 and MFN2 in the hippocampus was down-regulated, the expression of DRP1, IL-6, IL-1β and TNF-α in the hippocampus was up-regulated, the MMP and content of ATP were decreased, and the level of ROS was increased in S group ( P<0.05). Compared with S group, the time of stay at the new-arm and time spent on the rotarod were significantly prolonged, the percentage of movement distance in the new-arm was increased, the expression of PPARγ, PGC1α, MFN1 and MFN2 in the hippocampus was up-regulated, the expression of DRP1, IL-6, IL-1β and TNF-α in the hippocampus was down-regulated, the MMP and content of ATP were increased, and the level of ROS was decreased in PS1 group ( P<0.05). Part Ⅱ Compared with PS2 group, the time of stay at the new-arm and time spent on the rotarod were significantly shortened, the percentage of movement distance in the new-arm was decreased, the MMP and content of ATP were decreased, the level of ROS was increased, and the expression of IL-6, IL-1β and TNF-α was up-regulated ( P<0.05). Conclusions:The mechanism by which ω-3 PUFAs prevent brain neurotoxicity caused by multiple sevoflurane anesthesia is related to the activation of the PPARγ/PGC1α signaling pathway and alleviation of mitochondrial dysfunction and neuroinflammation in neonatal mice.

Objective:To evaluate the role of docosahexaenoic acid (DHA) in long-term cognitive impairment after multiple sevoflurane anesthesia in newborn mice.Methods:Clean-grade healthy male C57BL/6 mice, aged 6 days, were used in this study. Ten mice were divided into 2 groups ( n=5 each) by the random number table method: control group (group C) and sevoflurane group (group S). The animals inhaled 3% sevoflurane for 2 h at 6, 7 and 8 days after birth. The DHA content was detected by ultra-high performance liquid chromatography-mass spectrometry at 9 days of age. Fifty-two mice were selected and divided into 4 groups ( n=13 each) by a random number table method: control+ normal saline group (group C+ S), sevoflurane anesthesia + normal saline group (group S+ S), control+ DHA group (group C+ D), and sevoflurane anesthesia+ DHA group (group S+ D). The sevoflurane anesthesia method was the same as the one mentioned above. DHA 50 mg/kg was administered by intragastric gavage from postnatal days 6-19 (at 6, 7 and 8 days after birth, 2 h before anesthesia) in C+ D and S+ D groups. The equal volume of normal saline was given instead in C+ S group and S+ S group. The novel object recognition test was conducted at 37 days of age, and the Morris water maze test was performed at 42 days of age. The corpus callosum and hippocampal tissues were isolated at 47 days of age for examination of the ultrastructure of myelin (with a transmission electron microscope) and for determination of the expression of myelin basic protein (MBP) in hippocampal tissues (by Western blot). The G-ratio was calculated. Results:Compared with group C, the content of DHA in hippocampal tissues was significantly decreased in group S ( P<0.05). Compared with group C+ S, the discrimination index was significantly decreased, the percentage of duration of staying at the target platform quadrant and the number of crossing the original platform were decreased, the expression of MBP was down-regulated, and the G-ratio in the original platform and hippocampus was increased in S+ S group ( P<0.05). Compared with group S+ S, the discrimination index was significantly increased, the percentage of duration of staying at the target platform quadrant and the number of crossing the original platform were increased, the expression of MBP was up-regulated, and the G-ratio in the original platform and hippocampus was decreased in S+ D group ( P<0.05). Conclusions:The mechanism of long-term cognitive impairment following multiple sevoflurane anesthesia may be related to a decrease in the content of DHA, which subsequently leads to myelin structural damage in neonatal mice.

Objective:To evaluate the effect of multiple sevoflurane anesthesia on the metabolism of long-chain fatty acids in the hippocampus of newborn mice and the role of peroxisome proliferator-activated receptor-beta (PPARβ).Methods:Clean-grade healthy male C57BL/6 mice, aged 6 days, weighing 3-5 g, were divided into 2 groups ( n=8 each) by a random number table method: control group (group C) and multiple sevoflurane anesthesia group (group S). This study was performed in 2 parts. PartⅠ Sixteen newborn mice were divided into 2 groups ( n=8 each) using a random number table: control group (C group) and multiple sevoflurane anesthesia group (S group). Anesthesia was performed with sevoflurane on postnatal days 6, 7 and 8. The hippocampus was obtained at postnatal day 9 for determination of the content of long-chain fatty acids (by ultra-high performance liquid mass spectrometry), expression of PPARβ (by Western blot), and expression of stearoyl-CoA desaturase-2 (Scd2) and fatty acid desaturase 2 (Fads2) mRNA (using quantitative real-time polymerase chain reaction). Part Ⅱ Twenty-one newborn mice were divided into 3 groups ( n=7 each) using a random number table: control+ normal saline group (group C+ S), sevoflurane + normal saline group (group S+ S), and sevoflurane+ PPARβ specific agonist KD3010 group (group S+ K). Anesthesia was carried out with sevoflurane on postnatal days 6, 7 and 8. KD3010 25 mg/kg was intraperitoneally injected once a day from postnatal day 6 to 13 in S+ K group. The novel object recognition test was performed on postnatal day 37, and the Morris water maze test was performed on postnatal day 42. The hippocampal tissues were obtained on postnatal day 47 for detection of the expression of Scd2 mRNA and Fads2 mRNA by fluorescent quantitative real-time polymerase chain reaction. Anesthesia was carried out with sevoflurane as follows: Mice were exposed to 3% sevoflurane in 40% oxygen-60% nitrogen in an induction chamber for 2 h at a flow rate of 1 L/min. Results:PartⅠ Compared with group C, the total content of long-chain fatty acids, contents of saturated fatty acids, monounsaturated fatty acids and polyunsaturated fatty acids were significantly decreased, the percentage of saturated fatty acids was increased, the percentage of monounsaturated fatty acids and polyunsaturated fatty acids was decreased, the expression of Scd2 mRNA and Fads2 mRNA was down-regulated, and the expression of PPARβ was down-regulated in group S ( P<0.05). Part Ⅱ Compared with group C+ S, the discrimination index in the novel object recognition test and percentage of time spent in the target quadrant were significantly decreased, the number of crossing the original platform was reduced, and the expression of Scd2 and Fads2 mRNA was down-regulated in group S+ S ( P<0.05). Compared with group S+ S, the discrimination index in the novel object recognition test and percentage of time spent in the target quadrant were significantly increased, the number of crossing the original platform was increased, and the expression of Scd2 and Fads2 mRNA was up-regulated in group S+ K ( P<0.05). Conclusions:Multiple anesthesia with sevoflurane can lead to the disorder of long-chain fatty acid metabolism in the hippocampus of neonatal mice, resulting in long-term cognitive dysfunction. The mechanism may be related to inhibiting the activity of hippocampal PPARβ signaling pathway.

Objective To examine the changing prevalence and antimicrobial resistance profiles of Burkholderia cepacia in 52 hospitals across China from 2015 to 2021.Methods A total of 9 261 strains of B.cepacia were collected from 52 hospitals between January 1,2015 and December 31,2021.Antimicrobial susceptibility of the strains was tested using Kirby-Bauer method or automated antimicrobial susceptibility testing systems according to a unified protocol.The results were interpreted according to the breakpoints released in the Clinical & Laboratory Standards Institute(CLSI)guidelines(2023 edition).Results A total of 9 261 strains of B.cepacia were isolated from all age groups,especially elderly patients.The proportion was 11.1％(1 032 strains)in children,significantly lower than the proportion in adults.About half(46.5％,4 310/9 261)of the strains were isolated from patients at least 60 years old and 42.3％(3 919/9 261)of the strains were isolated from young adults.Most isolates(71.1％)were isolated from sputum and respiratory secretions,followed by urine(10.7％)and blood samples(8.1％).B.cepacia isolates were highly susceptible to the five antimicrobial agents recommended in the CLSI M100 document(33rd edition,2023).B.cepacia isolates showed relatively higher resistance rates to meropenem and levofloxacin.However,the resistance rates to ceftazidime,trimethoprim-sulfamethoxazole,and minocycline remained below 8.1％.The percentage of B.cepacia strains resistant to levofloxacin was the highest compared to other antibiotics in any of the three age groups(from 12.4％in the patients＜18 years old to 20.6％in the patients aged 60 years or older).Conclusions B.cepacia is one of the clinically important non-fermenting gram-negative bacteria.Accurate and timely reporting of antimicrobial susceptibility test results and ongoing antimicrobial resistance surveillance are helpful for rational prescription of antimicrobial agents and proper prevention and control of nosocomial infections.

Objective To summarize the changing prevalence of carbapenem resistance in Enterobacterales based on the data of CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021 for improving antimicrobial treatment in clinical practice.Methods Antimicrobial susceptibility testing was performed using a commercial automated susceptibility testing system according to the unified CHINET protocol.The results were interpreted according to the breakpoints of the Clinical & Laboratory Standards Institute(CLSI)M100 31st ed in 2021.Results Over the seven-year period(2015-2021),the overall prevalence of carbapenem-resistant Enterobacterales(CRE)was 9.43％(62 342/661 235).The prevalence of CRE strains in Klebsiella pneumoniae,Citrobacter freundii,and Enterobacter cloacae was 22.38％,9.73％,and 8.47％,respectively.The prevalence of CRE strains in Escherichia coli was 1.99％.A few CRE strains were also identified in Salmonella and Shigella.The CRE strains were mainly isolated from respiratory specimens(44.23±2.80)％,followed by blood(20.88±3.40)％and urine(18.40±3.45)％.Intensive care units(ICUs)were the major source of the CRE strains(27.43±5.20)％.CRE strains were resistant to all the β-lactam antibiotics tested and most non-β-lactam antimicrobial agents.The CRE strains were relatively susceptible to tigecycline and polymyxins with low resistance rates.Conclusions The prevalence of CRE strains was increasing from 2015 to 2021.CRE strains were highly resistant to most of the antibacterial drugs used in clinical practice.Clinicians should prescribe antimicrobial agents rationally.Hospitals should strengthen antibiotic stewardship in key clinical settings such as ICUs,and take effective infection control measures to curb CRE outbreak and epidemic in hospitals.

Objective To characterize the changing species distribution and antibiotic resistance profiles of respiratory isolates in hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Methods Commercial automated antimicrobial susceptibility testing systems and disk diffusion method were used to test the susceptibility of respiratory bacterial isolates to antimicrobial agents following the standardized technical protocol established by the CHINET program.Results A total of 589 746 respiratory isolates were collected from 2015 to 2021.Overall,82.6％of the isolates were Gram-negative bacteria and 17.4％were Gram-positive bacteria.The bacterial isolates from outpatients and inpatients accounted for(6.0±0.9)％and(94.0±0.1)％,respectively.The top microorganisms were Klebsiella spp.,Acinetobacter spp.,Pseudomonas aeruginosa,Staphylococcus aureus,Haemophilus spp.,Stenotrophomonas maltophilia,Escherichia coli,and Streptococcus pneumoniae.Each microorganism was isolated from significantly more males than from females(P＜0.05).The overall prevalence of methicillin-resistant S.aureus(MRSA)was 39.9％.The prevalence of penicillin-resistant S.pneumoniae was 1.4％.The prevalence of extended-spectrum β-lactamase(ESBL)-producing E.coli and K.pneumoniae was 67.8％and 41.3％,respectively.The overall prevalence of carbapenem-resistant E.coli,K.pneumoniae,Enterobacter cloacae,Pseudomonas aeruginosa,and Acinetobacter baumannii was 3.7％,20.8％,9.4％,29.8％,and 73.3％,respectively.The prevalence of β-lactamase was 96.1％in Moraxella catarrhalis and 60.0％in Haemophilus influenzae.The H.influenzae isolates from children(＜18 years)showed significantly higher resistance rates to β-lactam antibiotics than the isolates from adults(P＜0.05).Conclusions Gram-negative bacteria are still predominant in respiratory isolates associated with serious antibiotic resistance.Antimicrobial resistance surveillance should be strengthened in clinical practice to support accurate etiological diagnosis and appropriate antimicrobial therapy based on antimicrobial susceptibility testing results.

This paper reported a type 1 diabetes patient who had severe diabetic nephropathy, retinopathy, hypertension, and hypothyroidism before pregnancy. The patient's blood glucose control was poor before pregnancy, and the complications were not properly treated. This was an unintended pregnancy, with a pre-pregnancy glycated hemoglobin A1c of 7.8% and early pregnancy urine protein of 3.81-4.53 g/24 h. Considering the patient's poor blood glucose control before pregnancy and the lack of proper treatment for multiple complications including nephropathy, a multidisciplinary consultation at an external hospital recommended termination of the pregnancy. However, the patient was determined to continue the pregnancy and was referred to Peking University First Hospital. Through strict blood glucose control, monitoring and evaluation of complications, and comprehensive management, the patient's blood glucose and blood pressure were well controlled during pregnancy. Regular monitoring of urine protein, renal function, and ocular fundus was conducted. At 31 weeks and 4 days of gestation, the patient's 24-hour urine protein significantly increased. After promoting fetal lung maturity, a cesarean section was performed at 34 weeks and 1 day of gestation, resulting in a successful delivery with good maternal and neonatal outcomes. At the 42-day postpartum follow-up, the patient's blood glucose and blood pressure were stable, urine protein returned to pre-pregnancy levels, and the infant was in good general condition.

Objective:To evaluate the role of fibrinogen in perioperative neurocognitive disorder (PND) in aged mice.Methods:Sixty SPF healthy male C57BL/6J mice, aged 16-18 months, weighing 25-30 g, were divided into 4 groups ( n=15 each) using a random number table method: control group (group C), PND group (group P), urokinase group (group U) and PND+ urokinase group (group PU). Abdominal surgery was performed under 3% sevoflurane anesthesia to establish the mouse model of PND. In PU group, urokinase 20 000 U/kg was intraperitoneally administered at 1 h after surgery, once a day, for 5 consecutive days. In group U, urokinase was intraperitoneally injected once a day for 5 consecutive days without anesthesia and surgery. The cognitive function was assessed after operation using the novel object recognition test (discrimination index) and the Morris water maze test (frequency of crossing the original platform and percentage of the time spent in the target quadrant). The expression of occludin, claudin-5, fibrinogen and ionized calcium-binding adapter molecule 1 (Iba-1) and CD11b in hippocampal tissues was detected using Western blot, the area of fibrinogen extravascular deposits was measured and the morphology of microglia was observed using the immunofluorescence staining, and the mRNA expression of pro-inflammatory factors (interleukin-1beta, tumor necrosis factor-alpha, and inducible nitric oxide synthase), anti-inflammatory factors (interleukin-4 and arginase-1), and chemokines (chemokine 2 and chemokine ligand 10) in hippocampal tissues was detected by quantitative real-time polymerase chain reaction after surgery. Results:Compared with group C, the parameters of cognitive function were significantly decreased, the expression of occludin and claudin-5 was down-regulated, the expression of fibrinogen was up-regulated, the area of fibrinogen extravascular deposits was increased, the number of branches was decreased and the average process length was shortened in the microglia around fibrinogen deposits, the expression of Iba-1 and CD11b was up-regulated, the mRNA expression of proinflammatory cytokines and chemokines was up-regulated, and the mRNA expression of the anti-inflammatory factors was down-regulated in group PND ( P<0.05). Compared with group PND, the parameters of cognitive function were significantly increased, the expression of occludin and claudin-5 was up-regulated, the expression of fibrinogen was down-regulated, the area of fibrinogen extravascular deposits was decreased, the number of branches was increased and the average process length was prolonged in the microglia around fibrinogen deposits, the expression of Iba-1 and CD11b was down-regulated, the mRNA expression of proinflammatory cytokines and chemokines was down-regulated, and the mRNA expression of the anti-inflammatory factors was up-regulated in group PU ( P<0.05). Conclusions:Fibrinogen deposits in the brain parenchyma through the damaged blood-brain barrier after anesthesia and surgery and participates in the development of PND, and the underlying mechanism may be related to the promotion of microglial activation and the induction of neuroinflammation in aged mice.

Objective:To evaluate the relationship between the mechanism of ω-3 polyunsaturated fatty acids (ω-3 PUFAs) preventing sevoflurane-induced neurotoxicity and phosphorylated Tau glymphatic system clearance pathway in neonatal mice.Methods:Eighteen C57BL/6 pregnant mice were used in this study and subjected to 2 feeding regiments using the random number table method. Twelve mice were selected to receive a standard diet, and 6 mice were selected to receive a diet supplemented with fish oil (ω-3 polyunsaturated fatty acids [300 mg was added to every 20 g of standard diet from the 2nd day of gestation to 14 days after parturition). The healthy neonatal mice of both sexes, aged 6 days, weighing 3-5 g, were selected after parturition. Forty-eight neonatal pups from 6 pregnant mice that were fed a standard diet were assigned to control group (C group), 48 neonatal pups from 6 pregnant mice that were fed a standard diet were assigned to sevoflurane group (S group), and 48 neonatal pups from pregnant mice that were fed a diet supplemented with fish oil were assigned to ω-3 PUFAs plus sevoflurane group (PS group) using the random number table method. All the offspring mice in all groups were breastfed until 21 days of birth and then were housed in separate cages from their mothers after 21 days of birth and provided with ad libitum access to standard food. S group and PS group inhaled 3% sevoflurane and 40% oxygen for 2 h daily on postnatal days 6, 7 and 8. C group inhaled only 40% oxygen at the same flow rate. Y maze test was performed at postnatal day 33 to assess the spatial memory and cognitive function. The rotarod test was performed at postnatal day 35 to assess the fine motor coordination. The influx and efflux functions of the glymphatic system were assessed through intracisternal tracer infusion with the fluorescent tracer at postnatal days 14 and 35. The influx function was evaluated by the percentage of the area of tracer penetration 30 min after injection, while the efflux function was determined by the percentage of the residual area of the tracer 90 min after injection. The mice were sacrificed and the hippocampal tissue was obtained at postnatal day 14 for determination of the expression of phosphorylated Tau protein at serine 202 site and threonine 205 site (Tau-PS202/PT205) and total Tau protein by Western blot. The cerebrospinal fluid (CSF) was collected at postnatal day 14 for determination of the concentration of phosphorylated Tau protein by enzyme-linked immunosorbent assay. The mice were sacrificed and the hippocampal tissue was obtained at postnatal day 35 for determination of the expression of caspase-3, caspase-9 and cytochrome C (Cyt c) (by Western blot) and the apoptosis rate of neurons (by TUNEL).Results:Compared with C group, the time of staying at the new arm and in the rotarod test was significantly shortened, the percentage of new arm movement distance was decreased, the percentage of tracer penetration area was decreased at postnatal day 14, the percentage of residual tracer area was increased at postnatal day 14, the expression of Tau-PS202/PT205 in the hippocampus was up-regulated at postnatal day 14, the concentration of phosphorylated Tau protein in CSF was reduced at postnatal day 14, the apoptosis rate of hippocampal neurons was increased at postnatal day 35 ( P<0.05), and the expression of caspase-3, caspase-9 and Cyt c in the hippocampus was up-regulated at postnatal day 35 in S group ( P<0.05). Compared with S group, the time of staying at the new arm and in the rotarod test was significantly prolonged, the percentage of new arm movement distance was increased, the percentage of tracer penetration area was increased at postnatal day 14, the percentage of residual tracer area was decreased at postnatal day 14, the expression of Tau-PS202/PT205 in the hippocampus was down-regulated at postnatal day 14, the concentration of phosphorylated Tau protein in CSF was increased at postnatal day 14, the apoptosis rate of hippocampal neurons was decreased at postnatal day 35, and the expression of caspase-3, caspase-9 and Cyt c in the hippocampus was down-regulated at postnatal day 35 in PS group ( P<0.05). Conclusions:The mechanism by which ω-3 PUFAs prevents cerebral neurotoxicity induced by repeated neonatal sevofurane exposure may be related to the enhancement of phosphorylated Tau protein clearance via the glymphatic system.

Objective:To evaluate the relationship between the mechanism of ω-3 polyunsaturated fatty acids (ω-3 PUFAs) in preventing brain neurotoxicity caused by multiple sevoflurane anesthesia and peroxisome proliferator-activated receptor gamma (PPARγ)/peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α) signaling pathway in neonatal mice.Methods:This study was performed in 2 parts. Part Ⅰ Using a random number table method, 6 C57BL/6 pregnant mice were assigned to receive a standard diet, 3 pregnant mice were assigned to receive a diet supplemented with fish oil from day 2 of gestation to day 14 after parturition (ω-3 PUFAs 300 mg were added to every 20 g of conventional diet). Healthy C57BL/6 mice of both sexes, aged 6 days, weighing 3-5 g, were selected after parturition. Seventeen neonatal pups from 3 pregnant mice that were fed a conventional diet were assigned to control group (C group), 17 neonatal pups from 3 pregnant mice that were fed a conventional diet were assigned to sevoflurane group (S group), and 17 neonatal pups from pregnant mice that were fed a diet supplemented with fish oil were assigned to ω-3 PUFAs plus sevoflurane group (PS1 group) using the random number table method. Part Ⅱ Four C57BL/6 pregnant mice were assigned to receive a diet supplemented with fish oil from day 2 of gestation to day 14 after parturition. After parturition, 12 neonatal pups from 2 pregnant mice that were fed a diet supplemented with fish oil were assigned to ω-3 PUFAs plus sevoflurane group (PS2 group), and 12 neonatal pups from 2 pregnant mice that were fed a diet supplemented with fish oil were assigned to ω-3 PUFAs plus PPARγ inhibitor GW9662 plus sevoflurane group (PGS group) using a random number table method. GW9662 (2 mg/kg) was intraperitoneally injected at 30 min before exposure to sevoflurane in PGS group. All offspring mice were breastfed until 21 days of age, after which they were housed separately from the mother and allowed ad libitum access to a conventional diet. S, PS1, PS2 and PGS groups inhaled 3% sevoflurane in 40% oxygen for 2 h daily on postnatal days 6, 7 and 8. C group inhaled only 40% oxygen instead. Y maze test was performed on days 33 after birth. The rotarod test was performed on day 35 after birth. After the behavioral testing, the expression of PPARγ, PGC1α, mitofusin-1 (MFN1), MFN2, dynamin-related protein 1 (DRP1), interleukin-6 (IL-6), interleukin-1 β (IL-1 β), and tumor necrosis factor-α (TNF-α) was detected by Western blot, the ultrastructure of mitochondria in hippocampal neurons was observed with a transmission electron microscope, and the mitochondrial membrane potential (MMP), level of reactive oxygen species (ROS) and content of ATP were determined.Results:Part Ⅰ Compared with C group, the time of stay at the new-arm and time spent on the rotarod were significantly shortened, the percentage of movement distance in the new-arm was decreased, the expression of PPARγ, PGC1α, MFN1 and MFN2 in the hippocampus was down-regulated, the expression of DRP1, IL-6, IL-1β and TNF-α in the hippocampus was up-regulated, the MMP and content of ATP were decreased, and the level of ROS was increased in S group ( P<0.05). Compared with S group, the time of stay at the new-arm and time spent on the rotarod were significantly prolonged, the percentage of movement distance in the new-arm was increased, the expression of PPARγ, PGC1α, MFN1 and MFN2 in the hippocampus was up-regulated, the expression of DRP1, IL-6, IL-1β and TNF-α in the hippocampus was down-regulated, the MMP and content of ATP were increased, and the level of ROS was decreased in PS1 group ( P<0.05). Part Ⅱ Compared with PS2 group, the time of stay at the new-arm and time spent on the rotarod were significantly shortened, the percentage of movement distance in the new-arm was decreased, the MMP and content of ATP were decreased, the level of ROS was increased, and the expression of IL-6, IL-1β and TNF-α was up-regulated ( P<0.05). Conclusions:The mechanism by which ω-3 PUFAs prevent brain neurotoxicity caused by multiple sevoflurane anesthesia is related to the activation of the PPARγ/PGC1α signaling pathway and alleviation of mitochondrial dysfunction and neuroinflammation in neonatal mice.