Astrocytes are increasingly recognized to play an active role in learning and memory,but whether neural inputs can trigger event-specific astrocytic Ca^(2+)dynamics in real time to participate in working memory remain...Astrocytes are increasingly recognized to play an active role in learning and memory,but whether neural inputs can trigger event-specific astrocytic Ca^(2+)dynamics in real time to participate in working memory remains unclear due to the difficulties in directly monitoring astrocytic Ca^(2+)dynamics in animals performing tasks.Here,using fiber photometry,we showed that population astrocytic Ca^(2+)dynamics in the hippocampus were gated by sensory inputs(centered at the turning point of the T-maze)and modified by the reward delivery during the encoding and retrieval phases.Notably,there was a strong inter-locked and antagonistic relationship between the astrocytic and neuronal Ca^(2+)dynamics with a 3-s phase difference.Furthermore,there was a robust synchronization of astrocytic Ca^(2+)at the population level among the hippocampus,medial prefrontal cortex,and striatum.The inter-locked,bidirectional communication between astrocytes and neurons at the population level may contribute to the modulation of information processing in working memory.展开更多
Chromatin interactions functionally affect genome architecture and gene regulation,but to date,only fresh samples must be used in High-through chromosome conformation capture(Hi-C)to keep natural chromatin conformatio...Chromatin interactions functionally affect genome architecture and gene regulation,but to date,only fresh samples must be used in High-through chromosome conformation capture(Hi-C)to keep natural chromatin conformation intact.This requirement has impeded the advancement of 3 D genome research by limiting sample collection and storage options for researchers and severely limiting the number of samples that can be processed in a short time.Here,we develop a freeze substitution Hi-C(FS-Hi-C)technique that overcomes the need for fresh samples.FS-Hi-C can be used with samples stored in liquid nitrogen(LN2):the water in a vitreous form in the sample cells is replaced with ethanol via automated freeze substitution.After confirming that the FS step preserves the natural chromosome conformation during sample thawing,we tested the performance of FS-Hi-C with Drosophila melanogaster and Gossypium hirsutum.Beyond allowing the use of frozen samples and confirming that FS-Hi-C delivers robust data for generating contact heat maps and delineating A/B compartments and topologically associating domains,we found that FS-HiC outperforms the in situ Hi-C in terms of library quality,reproducibility,and valid interactions.Thus,FS-HiC will probably extend the application of 3D genome structure analysis to the vast number of experimental contexts in biological and medical research for which Hi-C methods have been unfeasible to date.展开更多
基金This work was supported by Start-up Funds from Wenzhou Medical University(89211010 and 89212012)the National Natural Science Foundation of China(81630040,31771178,and 81600991)the Natural Science Foundation of Zhejiang Province of China(LY21H090014 and LQ18C090002).
文摘Astrocytes are increasingly recognized to play an active role in learning and memory,but whether neural inputs can trigger event-specific astrocytic Ca^(2+)dynamics in real time to participate in working memory remains unclear due to the difficulties in directly monitoring astrocytic Ca^(2+)dynamics in animals performing tasks.Here,using fiber photometry,we showed that population astrocytic Ca^(2+)dynamics in the hippocampus were gated by sensory inputs(centered at the turning point of the T-maze)and modified by the reward delivery during the encoding and retrieval phases.Notably,there was a strong inter-locked and antagonistic relationship between the astrocytic and neuronal Ca^(2+)dynamics with a 3-s phase difference.Furthermore,there was a robust synchronization of astrocytic Ca^(2+)at the population level among the hippocampus,medial prefrontal cortex,and striatum.The inter-locked,bidirectional communication between astrocytes and neurons at the population level may contribute to the modulation of information processing in working memory.
基金supported by funding from the National Natural Science Foundation of China,China(grants 31621005 and 31600093 to F.G.L.)the Young Elite Scientists Sponsorship Program by CAST(2019zx08010033-002-012 to Z.E.Y.)Central Public-interest Scientific Institution Basal Research Fund(Y2020PT13)。
文摘Chromatin interactions functionally affect genome architecture and gene regulation,but to date,only fresh samples must be used in High-through chromosome conformation capture(Hi-C)to keep natural chromatin conformation intact.This requirement has impeded the advancement of 3 D genome research by limiting sample collection and storage options for researchers and severely limiting the number of samples that can be processed in a short time.Here,we develop a freeze substitution Hi-C(FS-Hi-C)technique that overcomes the need for fresh samples.FS-Hi-C can be used with samples stored in liquid nitrogen(LN2):the water in a vitreous form in the sample cells is replaced with ethanol via automated freeze substitution.After confirming that the FS step preserves the natural chromosome conformation during sample thawing,we tested the performance of FS-Hi-C with Drosophila melanogaster and Gossypium hirsutum.Beyond allowing the use of frozen samples and confirming that FS-Hi-C delivers robust data for generating contact heat maps and delineating A/B compartments and topologically associating domains,we found that FS-HiC outperforms the in situ Hi-C in terms of library quality,reproducibility,and valid interactions.Thus,FS-HiC will probably extend the application of 3D genome structure analysis to the vast number of experimental contexts in biological and medical research for which Hi-C methods have been unfeasible to date.
