Astrocytes, the major component of blood-brain barriers, have presented paradoxical profiles after cerebral ischemia and reperfusion in vivo and in vitro. Our previous study showed that sevoflurane preconditioning imp...Astrocytes, the major component of blood-brain barriers, have presented paradoxical profiles after cerebral ischemia and reperfusion in vivo and in vitro. Our previous study showed that sevoflurane preconditioning improved the integrity of blood-brain barriers after ischemia and reperfusion injury in rats. This led us to investigate the effects of sevoflurane preconditioning on the astrocytic dynamics in ischemia and reperfusion rats, in order to explore astrocytic cell-based mechanisms of sevoflurane preconditioning. In the present study, 2,3,5-triphenyltetrazolium chloride staining and Garcia behavioral scores were utilized to evaluate cerebral infarction and neurological outcome from day 1 to day 3 after transient middle cerebral artery occlusion surgery. Using immunofluorescent staining, we found that sevoflurane preconditioning substantially promoted the astrocytic activation and migration from the penumbra to the infarct with microglial activation from day 3 after middle cerebral artery occlusion. The formation of astrocytic scaffolds facilitated neuroblasts migrating from the subventricular zone to the lesion sites on day 14 after injury. Neural networks increased in the infarct of sevoflurane preconditioned rats, consistent with decreased infarct volume and improved neurological scores after ischemia and reperfusion injury. These findings demonstrate that sevoflurane preconditioning confers neuroprotection, not only by accelerating astrocytic spatial and temporal dynamics, but also providing astrocytic scaffolds for neuroblasts migration to ischemic regions, which facilitates neural reconstruction after brain ischemia.展开更多
In isolated chick retina, the visualization of electrochemical self-organized patterns is possible due to the presence of macroscopic intrinsic optical signals (IOSs). Isolated circular waves, standing patterns, and s...In isolated chick retina, the visualization of electrochemical self-organized patterns is possible due to the presence of macroscopic intrinsic optical signals (IOSs). Isolated circular waves, standing patterns, and self-sustained sequences of spirals are all easily obtained using an IOS approach. In this paper we present the tight coupling and non-linear relationship between optical and electrical wave concomitants, and potassium-induced whole tissue excitability changes. Elementary statistical methods and time series analyses were applied to two sets of data: 1) solitary circular retinal spreading depression waves, and 2) tissue response to exogenous potassium fast pulses. The results were interpreted from the point of view of non-linear thermodynamical concepts and volume phase transitions in polyanionic gels according to the Tasaki action potential model. From these and previous results, it is clear that the glial network and extracellular matrix contribute to the propagation and emergence of these patterns.展开更多
Dynamic structuring and functions of perisynaptic astrocytic processes and of the gap junction network within a single astrocyte are outlined. Motile perisynaptic astrocytic processes are generating microdomains. By c...Dynamic structuring and functions of perisynaptic astrocytic processes and of the gap junction network within a single astrocyte are outlined. Motile perisynaptic astrocytic processes are generating microdomains. By contacting and retracting of their endfeet an appropriate receptor pattern is selected that modulates the astrocytic receptor sheath for its activation by neurotransmitter substances, ions, transporters, etc. This synaptic information processing occurs in three distinct time scales of milliseconds to seconds, seconds to minutes, hours or longer. Simultaneously, the interconnecting gap junctions are activated by building a network within the astrocyte. Frequently activated gap junction cycles become embodied in gap junction plaques. The gap junction network formation and gap junction plaques are governed and controlled in the same time scales as synaptic information processing. Biomimetic computer systems may represent an alternative to limitations of brainphysiological research. The model proposed allows the interpretation of affective psychoses and schizophrenia as time disorders basically determined by a shortened, prolonged or lacking time scale of synaptic information processing.展开更多
Astrocytes(ASTs)and oligodendroglial lineage cells(OLGs)are major macroglial cells in the central nervous system.ASTs communicate with each other through connexin(Cx)and Cx-based network structures,both of which allow...Astrocytes(ASTs)and oligodendroglial lineage cells(OLGs)are major macroglial cells in the central nervous system.ASTs communicate with each other through connexin(Cx)and Cx-based network structures,both of which allow for quick transport of nutrients and signals.Moreover,ASTs interact with OLGs through connexin(Cx)-mediated networks to modulate various physiological processes in the brain.In this article,following a brief description of the infrastructural basis of the glial networks and exocrine factors by which ASTs and OLGs may crosstalk,we focus on recapitulating how the interactions between these two types of glial cells modulate myelination,and how the AST-OLG interactions are involved in protecting the integrity of the blood-brain barrier(BBB)and regulating synaptogenesis and neural activity.Recent studies further suggest that AST-OLG interactions are associated with myelin-related diseases,such as multiple sclerosis.A better understanding of the regulatory mechanisms underlying AST-OLG interactions may inspire the development of novel therapeutic strategies for related brain diseases.展开更多
基金supported by the National Natural Science Foundation of China,No.81200937(to QY)
文摘Astrocytes, the major component of blood-brain barriers, have presented paradoxical profiles after cerebral ischemia and reperfusion in vivo and in vitro. Our previous study showed that sevoflurane preconditioning improved the integrity of blood-brain barriers after ischemia and reperfusion injury in rats. This led us to investigate the effects of sevoflurane preconditioning on the astrocytic dynamics in ischemia and reperfusion rats, in order to explore astrocytic cell-based mechanisms of sevoflurane preconditioning. In the present study, 2,3,5-triphenyltetrazolium chloride staining and Garcia behavioral scores were utilized to evaluate cerebral infarction and neurological outcome from day 1 to day 3 after transient middle cerebral artery occlusion surgery. Using immunofluorescent staining, we found that sevoflurane preconditioning substantially promoted the astrocytic activation and migration from the penumbra to the infarct with microglial activation from day 3 after middle cerebral artery occlusion. The formation of astrocytic scaffolds facilitated neuroblasts migrating from the subventricular zone to the lesion sites on day 14 after injury. Neural networks increased in the infarct of sevoflurane preconditioned rats, consistent with decreased infarct volume and improved neurological scores after ischemia and reperfusion injury. These findings demonstrate that sevoflurane preconditioning confers neuroprotection, not only by accelerating astrocytic spatial and temporal dynamics, but also providing astrocytic scaffolds for neuroblasts migration to ischemic regions, which facilitates neural reconstruction after brain ischemia.
文摘In isolated chick retina, the visualization of electrochemical self-organized patterns is possible due to the presence of macroscopic intrinsic optical signals (IOSs). Isolated circular waves, standing patterns, and self-sustained sequences of spirals are all easily obtained using an IOS approach. In this paper we present the tight coupling and non-linear relationship between optical and electrical wave concomitants, and potassium-induced whole tissue excitability changes. Elementary statistical methods and time series analyses were applied to two sets of data: 1) solitary circular retinal spreading depression waves, and 2) tissue response to exogenous potassium fast pulses. The results were interpreted from the point of view of non-linear thermodynamical concepts and volume phase transitions in polyanionic gels according to the Tasaki action potential model. From these and previous results, it is clear that the glial network and extracellular matrix contribute to the propagation and emergence of these patterns.
文摘Dynamic structuring and functions of perisynaptic astrocytic processes and of the gap junction network within a single astrocyte are outlined. Motile perisynaptic astrocytic processes are generating microdomains. By contacting and retracting of their endfeet an appropriate receptor pattern is selected that modulates the astrocytic receptor sheath for its activation by neurotransmitter substances, ions, transporters, etc. This synaptic information processing occurs in three distinct time scales of milliseconds to seconds, seconds to minutes, hours or longer. Simultaneously, the interconnecting gap junctions are activated by building a network within the astrocyte. Frequently activated gap junction cycles become embodied in gap junction plaques. The gap junction network formation and gap junction plaques are governed and controlled in the same time scales as synaptic information processing. Biomimetic computer systems may represent an alternative to limitations of brainphysiological research. The model proposed allows the interpretation of affective psychoses and schizophrenia as time disorders basically determined by a shortened, prolonged or lacking time scale of synaptic information processing.
基金supported by the Ministry of Science and Technology of China(2021ZD0201700)the National Natural Science Foundation of China(31921003).
文摘Astrocytes(ASTs)and oligodendroglial lineage cells(OLGs)are major macroglial cells in the central nervous system.ASTs communicate with each other through connexin(Cx)and Cx-based network structures,both of which allow for quick transport of nutrients and signals.Moreover,ASTs interact with OLGs through connexin(Cx)-mediated networks to modulate various physiological processes in the brain.In this article,following a brief description of the infrastructural basis of the glial networks and exocrine factors by which ASTs and OLGs may crosstalk,we focus on recapitulating how the interactions between these two types of glial cells modulate myelination,and how the AST-OLG interactions are involved in protecting the integrity of the blood-brain barrier(BBB)and regulating synaptogenesis and neural activity.Recent studies further suggest that AST-OLG interactions are associated with myelin-related diseases,such as multiple sclerosis.A better understanding of the regulatory mechanisms underlying AST-OLG interactions may inspire the development of novel therapeutic strategies for related brain diseases.
