Neuron-astrocyte interactions are vital for the brain’s connectome.Understanding astrocyte activities is crucial for comprehending the complex neural network,particularly the population-level functions of neurons in ...Neuron-astrocyte interactions are vital for the brain’s connectome.Understanding astrocyte activities is crucial for comprehending the complex neural network,particularly the population-level functions of neurons in different cortical states and associated behaviors in mammals.Studies on animal sleep and wakefulness have revealed distinct cortical synchrony patterns between neurons.Astrocytes,outnumbering neurons by nearly fivefold,support and regulate neuronal and synaptic function.Recent research on astrocyte activation during cortical state transitions has emphasized the influence of norepinephrine as a neurotransmitter and calcium waves as key components of ion channel signaling.This summary focuses on a few recent studies investigating astrocyte-neuron interactions in mouse models during sleep,wakefulness,and arousal levels,exploring the involvement of noradrenaline signaling,ion channels,and glutamatergic signaling in different cortical states.These findings highlight the significant impact of astrocytes on large-scale neuronal networks,influencing brain activity and responsiveness.Targeting astrocytic signaling pathways shows promise for treating sleep disorders and arousal dysregulation.More research is needed to understand astrocytic calcium signaling in different brain regions and its implications for dysregulated brain states,requiring future human studies to comprehensively investigate neuron-astrocyte interactions and pave the way for therapeutic interventions in sleep-and arousal-related disorders.展开更多
Spatiotemporal multiple coherence resonances coupled hepatocytes are studied. It is shown that for calcium activities induced by weak Gaussian white noise in bi-resonances in hepatocytes are induced by the interplay a...Spatiotemporal multiple coherence resonances coupled hepatocytes are studied. It is shown that for calcium activities induced by weak Gaussian white noise in bi-resonances in hepatocytes are induced by the interplay and competition between noise and coupling of cells, in other words, the cell in network can be excited either by noise or by its neighbour via gap junction which can transfer calcium ions between cells. Furthermore, the intercellular annular calcium waves induced by noise are observed, in which the wave length decreases with noise intensity augmenting but increases monotonically with coupling strength increasing. And for a fixed noise level, there is an optimal coupling strength that makes the coherence resonance reach maximum.展开更多
In certain extracellular environments, there would appear a kind of solitary pulse calcium waves in Rana pipiens sympathetic neurons, propagating inwards along the radial direction from the plasma membrane. To gain a ...In certain extracellular environments, there would appear a kind of solitary pulse calcium waves in Rana pipiens sympathetic neurons, propagating inwards along the radial direction from the plasma membrane. To gain a deeper insight into the waves, a model describing intracellular calcium waves in frog sympathetic neurons was established. In the piecewise linear approximation, the present model is identical to the Sneyd model. Thus, with (Sneyd's) method, analytical expressions for the wave speed and profiles of 1-D solitary pulse wave were obtained. A wave speed of (21.5 μm/s) was deduced, which agrees rather well with experimental data.展开更多
It has been revealed experimentally that astrocytes can participate in synaptic transmission by modulating and responding to the release of neurotransmitters with calcium elevations. Researches suggest that seizure-li...It has been revealed experimentally that astrocytes can participate in synaptic transmission by modulating and responding to the release of neurotransmitters with calcium elevations. Researches suggest that seizure-like discharges(SDs) or seizure-like firings(SFs) in neurons, characterizing neurological disorder, may arise locally in restricted areas(focal area) and then propagate throughout the brain. But the underlying mechanism remains unclear. To study the possible role astrocytes playing in the SDs propagation, we construct a minimal neuron-astrocyte network model by connecting a neurons chain and an astrocytes chain.The focal area is modelled by an IP3 reservoir which provides persistent IP3 out-flux. The study suggests that calcium wave propagation in astrocytes determines the propagation of SDs in the connected neurons. On the other hand, SDs in neurons allows the calcium wave propagates longer distance in the astrocytes, which suggests the mutually cooperating of astrocytes and neurons in accomplishing SD propagation. Furthermore, once SDs propagate and occupy the neuron network, it could not be terminated by recovery of the focal area. The results may imply that treatment of brain disorders should not only focus on local area but the whole neuron network.展开更多
Objective To study the relation between serum calcium level and elevated BaPWV in Chinese subjects. Methods The relation between serum calcium level and elevated BaPWV was studied in 9 615 subjects. The mean value of...Objective To study the relation between serum calcium level and elevated BaPWV in Chinese subjects. Methods The relation between serum calcium level and elevated BaPWV was studied in 9 615 subjects. The mean value of left and right BaPWV was analyzed. BaPWV was defined as high when it was31 752.5 cm/s （the upper quartile） either side. Results The BaPWV and its elevated percentage progressively increased across the quartiles of the serum calcium level （P〈0.05）. The prevalence of elevated BaPWV was significantly higher in subjects of the second, third and highest quartiles than in those of the lowest quartile （26.9%, 28.4%, and 33.2%vs 23.7%, P=0.0116, P=0.0004, and P〈0.0001）. Logistic regression analysis revealed that the risk of elevated BaPWV was 1.32- fold higher in subjects of the highest quartile than in those of the lowest quartile （OR=1.32, 95%CI：1.08-1.60）. Conclusion The elevated serum calcium level is related to an elevated BaPWV and a higher risk of arterial stiffness, independent of conventional risk factors, in middle-aged and elderly Chinese subjects.展开更多
A modified spatially extended Tang-Othmer Ca2＋ model is used to study intracellular Ca2＋ spiral waves numerically. It is found that, as a local stimulation, the local agonist-binding on the cell membrane, which enha...A modified spatially extended Tang-Othmer Ca2＋ model is used to study intracellular Ca2＋ spiral waves numerically. It is found that, as a local stimulation, the local agonist-binding on the cell membrane, which enhances the local concentration of the messenger molecule inositol 1,4,5-trisphosphate（IP3）, can influence the dynamics of the spiral waves. 1） Strong enough stimuli can change the spiral wave from a meandering to a rigidly rotating one. 2） On the other hand, strong enough stimuli can suppress the spiral wave from the system. It provides the theoretical clue for controlling the spiral waves by stimulating the cell membrane.展开更多
基金supported by the Corbett Estate Fund(62285-531021-41800,to EW)the Helen Vosburg McCrillus Plummer and Robert Edward Lee Plummer,Jr.Chair Fund(to JHH).
文摘Neuron-astrocyte interactions are vital for the brain’s connectome.Understanding astrocyte activities is crucial for comprehending the complex neural network,particularly the population-level functions of neurons in different cortical states and associated behaviors in mammals.Studies on animal sleep and wakefulness have revealed distinct cortical synchrony patterns between neurons.Astrocytes,outnumbering neurons by nearly fivefold,support and regulate neuronal and synaptic function.Recent research on astrocyte activation during cortical state transitions has emphasized the influence of norepinephrine as a neurotransmitter and calcium waves as key components of ion channel signaling.This summary focuses on a few recent studies investigating astrocyte-neuron interactions in mouse models during sleep,wakefulness,and arousal levels,exploring the involvement of noradrenaline signaling,ion channels,and glutamatergic signaling in different cortical states.These findings highlight the significant impact of astrocytes on large-scale neuronal networks,influencing brain activity and responsiveness.Targeting astrocytic signaling pathways shows promise for treating sleep disorders and arousal dysregulation.More research is needed to understand astrocytic calcium signaling in different brain regions and its implications for dysregulated brain states,requiring future human studies to comprehensively investigate neuron-astrocyte interactions and pave the way for therapeutic interventions in sleep-and arousal-related disorders.
基金supported by the National Natural Science Foundation of China (Grant Nos 10432010 and 10872014)
文摘Spatiotemporal multiple coherence resonances coupled hepatocytes are studied. It is shown that for calcium activities induced by weak Gaussian white noise in bi-resonances in hepatocytes are induced by the interplay and competition between noise and coupling of cells, in other words, the cell in network can be excited either by noise or by its neighbour via gap junction which can transfer calcium ions between cells. Furthermore, the intercellular annular calcium waves induced by noise are observed, in which the wave length decreases with noise intensity augmenting but increases monotonically with coupling strength increasing. And for a fixed noise level, there is an optimal coupling strength that makes the coherence resonance reach maximum.
文摘In certain extracellular environments, there would appear a kind of solitary pulse calcium waves in Rana pipiens sympathetic neurons, propagating inwards along the radial direction from the plasma membrane. To gain a deeper insight into the waves, a model describing intracellular calcium waves in frog sympathetic neurons was established. In the piecewise linear approximation, the present model is identical to the Sneyd model. Thus, with (Sneyd's) method, analytical expressions for the wave speed and profiles of 1-D solitary pulse wave were obtained. A wave speed of (21.5 μm/s) was deduced, which agrees rather well with experimental data.
基金supported by the Fundamental Research Funds for the Central Universities of China(Grant No.2014QNA64(J.T.))
文摘It has been revealed experimentally that astrocytes can participate in synaptic transmission by modulating and responding to the release of neurotransmitters with calcium elevations. Researches suggest that seizure-like discharges(SDs) or seizure-like firings(SFs) in neurons, characterizing neurological disorder, may arise locally in restricted areas(focal area) and then propagate throughout the brain. But the underlying mechanism remains unclear. To study the possible role astrocytes playing in the SDs propagation, we construct a minimal neuron-astrocyte network model by connecting a neurons chain and an astrocytes chain.The focal area is modelled by an IP3 reservoir which provides persistent IP3 out-flux. The study suggests that calcium wave propagation in astrocytes determines the propagation of SDs in the connected neurons. On the other hand, SDs in neurons allows the calcium wave propagates longer distance in the astrocytes, which suggests the mutually cooperating of astrocytes and neurons in accomplishing SD propagation. Furthermore, once SDs propagate and occupy the neuron network, it could not be terminated by recovery of the focal area. The results may imply that treatment of brain disorders should not only focus on local area but the whole neuron network.
基金supported by the Key Laboratory for Endocrine and Metabolic Diseases,Ministry of Health(1994DP131044)National Nature Science Foundation of China(81170739,81170719,81222008,81370960)+3 种基金Shanghai New Excellent Youth Program(XYQ2011009)Shanghai Health Bureau(2011293)EFSD-CDS-Lilly Program for Collaborative Research between China and Europe(2011)Shanghai Shen Kang Hospital Development Center(SHDC12012301)
文摘Objective To study the relation between serum calcium level and elevated BaPWV in Chinese subjects. Methods The relation between serum calcium level and elevated BaPWV was studied in 9 615 subjects. The mean value of left and right BaPWV was analyzed. BaPWV was defined as high when it was31 752.5 cm/s （the upper quartile） either side. Results The BaPWV and its elevated percentage progressively increased across the quartiles of the serum calcium level （P〈0.05）. The prevalence of elevated BaPWV was significantly higher in subjects of the second, third and highest quartiles than in those of the lowest quartile （26.9%, 28.4%, and 33.2%vs 23.7%, P=0.0116, P=0.0004, and P〈0.0001）. Logistic regression analysis revealed that the risk of elevated BaPWV was 1.32- fold higher in subjects of the highest quartile than in those of the lowest quartile （OR=1.32, 95%CI：1.08-1.60）. Conclusion The elevated serum calcium level is related to an elevated BaPWV and a higher risk of arterial stiffness, independent of conventional risk factors, in middle-aged and elderly Chinese subjects.
基金Project supported by the Xuzhou Medical College Foundation,China (Grant No. 08kj08)
文摘A modified spatially extended Tang-Othmer Ca2＋ model is used to study intracellular Ca2＋ spiral waves numerically. It is found that, as a local stimulation, the local agonist-binding on the cell membrane, which enhances the local concentration of the messenger molecule inositol 1,4,5-trisphosphate（IP3）, can influence the dynamics of the spiral waves. 1） Strong enough stimuli can change the spiral wave from a meandering to a rigidly rotating one. 2） On the other hand, strong enough stimuli can suppress the spiral wave from the system. It provides the theoretical clue for controlling the spiral waves by stimulating the cell membrane.
