Neuroscientists have recognized the importance of astrocytes in regulating neurological function and their influence on the release of glial transmitters.Few studies,however,have focused on the effects of general anes...Neuroscientists have recognized the importance of astrocytes in regulating neurological function and their influence on the release of glial transmitters.Few studies,however,have focused on the effects of general anesthetic agents on neuroglia or astrocytes.Astrocytes can also be an important target of general anesthetic agents as they exert not only sedative,analgesic,and amnesic effects but also mediate general anesthetic-induced neurotoxicity and postoperative cognitive dysfunction.Here,we analyzed recent advances in understanding the mechanism of general anesthetic agents on astrocytes,and found that exposure to general anesthetic agents will destroy the morphology and proliferation of astrocytes,in addition to acting on the receptors on their surface,which not only affect Ca^(2+)signaling,inhibit the release of brain-derived neurotrophic factor and lactate from astrocytes,but are even involved in the regulation of the pro-and anti-inflammatory processes of astrocytes.These would obviously affect the communication between astrocytes as well as between astrocytes and neighboring neurons,other neuroglia,and vascular cells.In this review,we summarize how general anesthetic agents act on neurons via astrocytes,and explore potential mechanisms of action of general anesthetic agents on the nervous system.We hope that this review will provide a new direction for mitigating the neurotoxicity of general anesthetic agents.展开更多
General anesthetic agents can impact brain function through interactions with neurons and their effects on glial cells.Oligodendrocytes perform essential roles in the central nervous system,including myelin sheath for...General anesthetic agents can impact brain function through interactions with neurons and their effects on glial cells.Oligodendrocytes perform essential roles in the central nervous system,including myelin sheath formation,axonal metabolism,and neuroplasticity regulation.They are particularly vulnerable to the effects of general anesthetic agents resulting in impaired proliferation,differentiation,and apoptosis.Neurologists are increasingly interested in the effects of general anesthetic agents on oligodendrocytes.These agents not only act on the surface receptors of oligodendrocytes to elicit neuroinflammation through modulation of signaling pathways,but also disrupt metabolic processes and alter the expression of genes involved in oligodendrocyte development and function.In this review,we summarize the effects of general anesthetic agents on oligodendrocytes.We anticipate that future research will continue to explore these effects and develop strategies to decrease the incidence of adverse reactions associated with the use of general anesthetic agents.展开更多
The progress of modern medicine would be impossible without the use of general anesthetics(GAs).Despite advancements in refining anesthesia approaches,the effects of GAs are not fully reversible upon GA withdrawal.Neu...The progress of modern medicine would be impossible without the use of general anesthetics(GAs).Despite advancements in refining anesthesia approaches,the effects of GAs are not fully reversible upon GA withdrawal.Neurocognitive deficiencies attributed to GA exposure may persist in neonates or endure for weeks to years in the elderly.Human studies on the mechanisms of the long-term adverse effects of GAs are needed to improve the safety of general anesthesia but they are hampered not only by ethical limitations specific to human research,but also by a lack of specific biological markers that can be used in human studies to safely and objectively study such effects.The latter can primarily be attributed to an insufficient understanding of the full range of the biological effects induced by GAs and the molecular mechanisms mediating such effects even in rodents,which are far more extensively studied than any other species.Our most recent experimental findings in rodents suggest that GAs may adversely affect many more people than is currently anticipated.Specifically,we have shown that anesthesia with the commonly used GA sevoflurane induces in exposed animals not only neuroendocrine abnormalities(somatic effects),but also epigenetic reprogramming of germ cells(germ cell effects).The latter may pass the neurobehavioral effects of parental sevoflurane exposure to the offspring,who may be affected even at levels of anesthesia that are not harmful to the exposed parents.The large number of patients who require general anesthesia,the even larger number of their future unexposed offspring whose health may be affected,and a growing number of neurodevelopmental disorders of unknown etiology underscore the translational importance of investigating the intergenerational effects of GAs.In this mini review,we discuss emerging experimental findings on neuroendocrine,epigenetic,and intergenerational effects of GAs.展开更多
Debates regarding the specific effects of general anesthesia on developing brains have persisted for over 30 years.A consensus has been reached that prolonged,repeated,high-dose exposure to anesthetics is associated w...Debates regarding the specific effects of general anesthesia on developing brains have persisted for over 30 years.A consensus has been reached that prolonged,repeated,high-dose exposure to anesthetics is associated with a higher incidence of deficits in behavior and executive function,while single exposure has a relatively minor effect on long-term neurological function.In this review,we summarize the dose-dependent neuroprotective or neurotoxic effects of gamma-aminobutyric acid type A receptor agonists,a representative group of sedatives,on developing brains or central nervous system diseases.Most preclinical research indicates that anesthetics have neurotoxic effects on the developing brain through various signal pathways.However,recent studies on low-dose anesthetics suggest that they may promote neurodevelopment during this critical period.These findings are incomprehensible for the general“dose-effect”principles of pharmacological research,which has attracted researchers'interest and led to the following questions:What is the threshold for the dual effects exerted by anesthetics such as propofol and sevoflurane on the developing brain?To what extent can their protective effects be maximized?What are the underlying mechanisms involved in these effects?Consequently,this issue has essentially become a“mathematical problem.”After summarizing the dose-dependent effects of gamma-aminobutyric acid type A receptor agonist sedatives in both the developing brain and the brains of patients with central nervous system diseases,we believe that all such anesthetics exhibit specific threshold effects unique to each drug.These effects range from neuroprotection to neurotoxicity,depending on different brain functional states.However,the exact values of the specific thresholds for different drugs in various brain states,as well as the underlying mechanisms explaining why these thresholds exist,remain unclear.Further in-depth exploration of these issues could significantly enhance the therapeutic translational value of these anesthetics.展开更多
In many recent studies, the inhibitory transmitter gamma-aminobutyric acid has been shown to modulate the proliferation, differentiation and survival of neural stem cells. Most general anesthetics are partial or allos...In many recent studies, the inhibitory transmitter gamma-aminobutyric acid has been shown to modulate the proliferation, differentiation and survival of neural stem cells. Most general anesthetics are partial or allosteric gamma-aminobutyric acid A receptor agonists, suggesting that general anesthetics could alter the behavior of neural stem cells. The neuroprotective efficacy of general anesthetics has been recognized for decades, but their effects on the proliferation of neural stem cells have received little attention. This study investigated the potential effect of midazolam, an extensively used general anesthetic and allosteric gamma-aminobutyric acid A receptor agonist, on the proliferation of neural stem cells in vitro and preliminarily explored the underlying mechanism. The proliferation of neural stem cells was tested using both Cell Counting Kit 8 and bromodeoxyuridine incorporation experiments. Cell distribution analysis was performed to describe changes in the cell cycle distribution in response to midazolam. Calcium imaging was employed to explore the molecular signaling pathways activated by midazolam. Midazolam （30-90 IJM） decreased the proliferation of neural stem cells in vitro. Pretreatment with the gamma-aminobutyric acid A receptor antagonist bicuculline or Na-K-2CI cotransport inhibitor furosemide partially rescued this inhibition. In addition, midazolam triggered a calcium influx into neural stem cells. The suppressive effect of midazolam on the proliferation of neural stem cells can be partly attributed to the activation of gamma-aminobutyric acid A receptor. The calcium influx triggered by midazolam may be a trigger factor leading to further downstream events.展开更多
基金supported by the National Natural Science Foundation of China,Nos.82171260,81641042,81471240the Natural Science Foundation of Zhejiang Province,Nos.LZ22H090002 and 2014C33170(all to ZH)。
文摘Neuroscientists have recognized the importance of astrocytes in regulating neurological function and their influence on the release of glial transmitters.Few studies,however,have focused on the effects of general anesthetic agents on neuroglia or astrocytes.Astrocytes can also be an important target of general anesthetic agents as they exert not only sedative,analgesic,and amnesic effects but also mediate general anesthetic-induced neurotoxicity and postoperative cognitive dysfunction.Here,we analyzed recent advances in understanding the mechanism of general anesthetic agents on astrocytes,and found that exposure to general anesthetic agents will destroy the morphology and proliferation of astrocytes,in addition to acting on the receptors on their surface,which not only affect Ca^(2+)signaling,inhibit the release of brain-derived neurotrophic factor and lactate from astrocytes,but are even involved in the regulation of the pro-and anti-inflammatory processes of astrocytes.These would obviously affect the communication between astrocytes as well as between astrocytes and neighboring neurons,other neuroglia,and vascular cells.In this review,we summarize how general anesthetic agents act on neurons via astrocytes,and explore potential mechanisms of action of general anesthetic agents on the nervous system.We hope that this review will provide a new direction for mitigating the neurotoxicity of general anesthetic agents.
基金supported by the Natural Science Foundation of Zhejiang Province(LZ22H090002,2014C33170)National Natural Science Foundation of China(82171260,81641042,81471240)。
文摘General anesthetic agents can impact brain function through interactions with neurons and their effects on glial cells.Oligodendrocytes perform essential roles in the central nervous system,including myelin sheath formation,axonal metabolism,and neuroplasticity regulation.They are particularly vulnerable to the effects of general anesthetic agents resulting in impaired proliferation,differentiation,and apoptosis.Neurologists are increasingly interested in the effects of general anesthetic agents on oligodendrocytes.These agents not only act on the surface receptors of oligodendrocytes to elicit neuroinflammation through modulation of signaling pathways,but also disrupt metabolic processes and alter the expression of genes involved in oligodendrocyte development and function.In this review,we summarize the effects of general anesthetic agents on oligodendrocytes.We anticipate that future research will continue to explore these effects and develop strategies to decrease the incidence of adverse reactions associated with the use of general anesthetic agents.
基金Supported by National Institutes of Health,No.R01NS091542National Natural Science Foundation of China,No.81771149,No.U1704165。
文摘The progress of modern medicine would be impossible without the use of general anesthetics(GAs).Despite advancements in refining anesthesia approaches,the effects of GAs are not fully reversible upon GA withdrawal.Neurocognitive deficiencies attributed to GA exposure may persist in neonates or endure for weeks to years in the elderly.Human studies on the mechanisms of the long-term adverse effects of GAs are needed to improve the safety of general anesthesia but they are hampered not only by ethical limitations specific to human research,but also by a lack of specific biological markers that can be used in human studies to safely and objectively study such effects.The latter can primarily be attributed to an insufficient understanding of the full range of the biological effects induced by GAs and the molecular mechanisms mediating such effects even in rodents,which are far more extensively studied than any other species.Our most recent experimental findings in rodents suggest that GAs may adversely affect many more people than is currently anticipated.Specifically,we have shown that anesthesia with the commonly used GA sevoflurane induces in exposed animals not only neuroendocrine abnormalities(somatic effects),but also epigenetic reprogramming of germ cells(germ cell effects).The latter may pass the neurobehavioral effects of parental sevoflurane exposure to the offspring,who may be affected even at levels of anesthesia that are not harmful to the exposed parents.The large number of patients who require general anesthesia,the even larger number of their future unexposed offspring whose health may be affected,and a growing number of neurodevelopmental disorders of unknown etiology underscore the translational importance of investigating the intergenerational effects of GAs.In this mini review,we discuss emerging experimental findings on neuroendocrine,epigenetic,and intergenerational effects of GAs.
文摘Debates regarding the specific effects of general anesthesia on developing brains have persisted for over 30 years.A consensus has been reached that prolonged,repeated,high-dose exposure to anesthetics is associated with a higher incidence of deficits in behavior and executive function,while single exposure has a relatively minor effect on long-term neurological function.In this review,we summarize the dose-dependent neuroprotective or neurotoxic effects of gamma-aminobutyric acid type A receptor agonists,a representative group of sedatives,on developing brains or central nervous system diseases.Most preclinical research indicates that anesthetics have neurotoxic effects on the developing brain through various signal pathways.However,recent studies on low-dose anesthetics suggest that they may promote neurodevelopment during this critical period.These findings are incomprehensible for the general“dose-effect”principles of pharmacological research,which has attracted researchers'interest and led to the following questions:What is the threshold for the dual effects exerted by anesthetics such as propofol and sevoflurane on the developing brain?To what extent can their protective effects be maximized?What are the underlying mechanisms involved in these effects?Consequently,this issue has essentially become a“mathematical problem.”After summarizing the dose-dependent effects of gamma-aminobutyric acid type A receptor agonist sedatives in both the developing brain and the brains of patients with central nervous system diseases,we believe that all such anesthetics exhibit specific threshold effects unique to each drug.These effects range from neuroprotection to neurotoxicity,depending on different brain functional states.However,the exact values of the specific thresholds for different drugs in various brain states,as well as the underlying mechanisms explaining why these thresholds exist,remain unclear.Further in-depth exploration of these issues could significantly enhance the therapeutic translational value of these anesthetics.
基金support from the National Natural Science Foundation of China,No.30571791
文摘In many recent studies, the inhibitory transmitter gamma-aminobutyric acid has been shown to modulate the proliferation, differentiation and survival of neural stem cells. Most general anesthetics are partial or allosteric gamma-aminobutyric acid A receptor agonists, suggesting that general anesthetics could alter the behavior of neural stem cells. The neuroprotective efficacy of general anesthetics has been recognized for decades, but their effects on the proliferation of neural stem cells have received little attention. This study investigated the potential effect of midazolam, an extensively used general anesthetic and allosteric gamma-aminobutyric acid A receptor agonist, on the proliferation of neural stem cells in vitro and preliminarily explored the underlying mechanism. The proliferation of neural stem cells was tested using both Cell Counting Kit 8 and bromodeoxyuridine incorporation experiments. Cell distribution analysis was performed to describe changes in the cell cycle distribution in response to midazolam. Calcium imaging was employed to explore the molecular signaling pathways activated by midazolam. Midazolam （30-90 IJM） decreased the proliferation of neural stem cells in vitro. Pretreatment with the gamma-aminobutyric acid A receptor antagonist bicuculline or Na-K-2CI cotransport inhibitor furosemide partially rescued this inhibition. In addition, midazolam triggered a calcium influx into neural stem cells. The suppressive effect of midazolam on the proliferation of neural stem cells can be partly attributed to the activation of gamma-aminobutyric acid A receptor. The calcium influx triggered by midazolam may be a trigger factor leading to further downstream events.
