Award type：Award from Japanese society, conference, symposium, etc.  Country：Japan

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Iscience  

Two-photon imaging is essential for revealing the structure, function, and interaction of various cell types. However, conventional two-photon microscopes have limitations in sample accessibility and optogenetic manipulation during imaging. Here, we present Ex2p/Ex2pO, an open-source extension module that adds an objective lens rotation axis and one-photon optical stimulation synchronized with the non-imaging intervals of resonant scanning to a two-photon microscope. The Ex2p/Ex2pO can be seamlessly integrated into existing microscopes by simply replacing the standard objective lens assembly without any modifications. It enables imaging of curved structures while maintaining the subject's natural posture and simultaneous imaging and one-photon stimulation with low crosstalk between stimulation and fluorescent light. We demonstrate one-photon stimulation during two-photon imaging of mice behaving in a virtual reality environment and pluripotent stem cell-derived cortical organoids. Thus, Ex2p/Ex2pO expands the versatility to investigate neural circuit motifs in behaving animals and organoids, enabling all-optical physiology in existing two-photon imaging systems.

DOI： 10.1016/j.isci.2025.113525

Open Access

Web of Science

Scopus

PubMed

Authorship：Lead author   Language：English   Publishing type：Research paper (bulletin of university, research institution)  

DOI： 10.1101/2024.11.12.623320

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Authorship：Lead author   Language：English   Publishing type：Research paper (bulletin of university, research institution)   Publisher：Cold Spring Harbor Laboratory  

Predicting future events based on internal models is essential for animal survival. Predictive coding postulates that errors between prediction and observation in lower-order areas update predictions in higher-order areas through the hierarchy. However, it is unclear how predictive coding is implemented in the hierarchy of the brain. Herein, we report the neural mechanism of the hierarchical processing and transmission of bottom-up prediction error signals in the mouse cortex. Ca2+ imaging and electrophysiological recording in virtual reality revealed responses to visuomotor mismatches in the retrosplenial, dorsal visual, and anterior cingulate cortex. These mismatch responses were attenuated when mismatches became predictable through experience. Optogenetic inhibition of bottom-up signals reduced a behavioral indicator for prediction errors. Moreover, cellular-level mismatch responses were modeled by Bayesian inference using a state-space model. This study demonstrates hierarchical circuit organization underlying prediction error propagation, advancing the understanding of predictive coding in sensory perception and learning in the brain.

DOI： 10.1101/2022.08.16.504075

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Neuroscience Research  

Despite the crucial role of synaptic connections and neural activity in the development and organization of cortical circuits, the mechanisms underlying the formation of functional synaptic connections in the developing human cerebral cortex remain unclear. We investigated the development of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR)-mediated synaptic transmission using human cortical organoids (hCOs) derived from induced pluripotent stem cells. Two-photon Ca²⁺ imaging revealed an increase in the frequency and amplitude of spontaneous activity in hCOs on day 80 compared to day 50. Additionally, spontaneous neural activity in late-stage hCOs, but not in early-stage hCOs, was blocked by N-methyl-D-aspartate receptor (NMDAR) and AMPAR antagonists. However, transsynaptic circuit tracing with G-deleted rabies viral vectors indicated a similar number of synaptic connections in early- and late-stage hCOs. Notably, chemical labeling demonstrated a significant increase in AMPAR expression on the postsynaptic membrane and colocalization with NMDARs in late-stage hCOs. These results suggest that hCOs progressively organize excitatory synaptic transmission, concurrent with the transition from silent synapses lacking AMPARs to functional synapses containing NMDARs and AMPARs. This in vitro model of human cortical circuits derived from induced pluripotent stem cells reflects the developmental programs underlying physiological transitions, providing valuable insights into human corticogenesis and neurodevelopmental disorders.

DOI： 10.1016/j.neures.2024.12.008

Open Access

Web of Science

Scopus

PubMed

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Frontiers in Virology  

Persistent virus infection involves modifying the host immune response and maintaining viral infection. Acute infection with Mononegavirales, such as Sendai viruses (SeVs), can give rise to viruses capable of persistent infection. SeVs establish persistent infection through generating copyback-type defective interfering (cbDI) genomes or acquiring temperature-sensitive mutations. Herein, we identify novel mutations associated with persistent infection and recombinant SeV mutants capable of persistent infection and autonomous production at physiological body temperature, independent of cbDI genomes or temperature-sensitive mutations. Diverse SeV populations were generated by passing the cDNA-recovered SeV Z strain 19 times through embryonated chicken eggs and subsequently infecting LLC-MK2 cells with the SeV populations to finally obtain SeV mutants capable of persistent infection and autonomous production in several types of cultured cells. Sequence analysis identified 4 or 5 mutations in the genome of the persistently infectious SeVs, distinguishing them from other existing strains with persistent infection. Recombinant SeVs carrying 4 or 5 mutations in the Z strain genome (designated SeV-Zpi or SeV-Zpi2, respectively) exhibited persistent infection and autonomous production in LLC-MK2, BHK-21, and Neuro2a cells at 37°C. SeV-Zpi and SeV-Zpi2 consistently produced viral particles even after long-term passages without cbDI particles or temperature-sensitive phenotypes. These results highlight the ability of acute infections of SeVs to spontaneously acquire mutations during replication, thereby endowing persistent infection and autonomous production at body temperature. The vectorization of SeV-Zpi and SeV-Zpi2 will contribute to both basic research and medical applications.

DOI： 10.3389/fviro.2024.1363092

Open Access

Web of Science

Scopus

Authorship：Lead author   Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：(株)中外医学社  

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Event date： 2024 - 2024.7

Presentation type：Symposium, workshop panel (public)  

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