@article {69994, title = {A Multimodal Adaptive Optical Microscope For In Vivo Imaging from Molecules to Organisms}, journal = {bioRxiv}, year = {2025}, month = {2025 Jun 16}, abstract = {

Understanding biological systems requires observing features and processes across vast spatial and temporal scales, spanning nanometers to centimeters and milliseconds to days, often using multiple imaging modalities within complex native microenvironments. Yet, achieving this comprehensive view is challenging because microscopes optimized for specific tasks typically lack versatility due to inherent optical and sample handling trade-offs, and frequently suffer performance degradation from sample-induced optical aberrations in multicellular contexts. Here, we present MOSAIC, a reconfigurable microscope that integrates multiple advanced imaging techniques including light-sheet, label-free, super-resolution, and multi-photon, all equipped with adaptive optics. MOSAIC enables non-invasive imaging of subcellular dynamics in both cultured cells and live multicellular organisms, nanoscale mapping of molecular architectures across millimeter-scale expanded tissues, and structural/functional neural imaging within live mice. MOSAIC facilitates correlative studies across biological scales within the same specimen, providing an integrated platform for broad biological investigation.

Preprint:\ https://www.biorxiv.org/content/early/2025/06/13/2025.06.02.657494

}, doi = {10.1101/2025.06.02.657494}, url = {https://www.biorxiv.org/content/early/2025/06/13/2025.06.02.657494}, author = {Fu, Tian-Ming and Liu, Gaoxiang and Milkie, Daniel E. and Ruan, Xiongtao and G{\"o}rlitz, Frederik and Shi, Yu and Ferro, Valentina and Divekar, Nikita S. and Wang, Wei and York, Harrison M. and Kilic, Velat and Mueller, Matthew and Liang, Yajie and Daugird, Timothy A. and Gacha-Garay, Maria J. and Larkin, Kathryn A. and Adikes, Rebecca C. and Harrison, Nathaniel and Shirazinejad, Cyna and Williams, Samara and Nourse, Jamison L. and Sheu, Shu-Hsien and Gao, Liang and Li, Tongchao and Mondal, Chandrani and Achour, Kemal and Hercule, Wilmene and Stabley, Daniel and Emmerich, Kevin and Dong, Peng and Drubin, David and Liu, Zhe J. and Clapham, David and Mumm, Jeff S. and Koyama, Minoru and Killilea, Alison and Bravo-Cordero, Jose Javier and Keene, C. Dirk and Luo, Liqun and Kirchhausen, Tom and Pathak, Medha M. and Arumugam, Senthil and Nunez, James K. and Gao, Ruixuan and Matus, David Q. and Martin, Benjamin L. and Swinburne, Ian A. and Betzig, Eric and Legant, Wesley R. and Upadhyayula, Srigokul} } @article {68785, title = {Nanoparticle-based targeting of microglia improves the neural regeneration enhancing effects of immunosuppression in the zebrafish retina.}, journal = {Communications Biology}, volume = {6}, year = {2023}, month = {2023 May 18}, pages = {534}, abstract = {

Retinal M{\"u}ller glia function as injury-induced stem-like cells in zebrafish but not mammals. However, insights gleaned from zebrafish have been applied to stimulate nascent regenerative responses in the mammalian retina. For instance, microglia/macrophages regulate M{\"u}ller glia stem cell activity in the chick, zebrafish, and mouse. We previously showed that post-injury immunosuppression by the glucocorticoid dexamethasone accelerated retinal regeneration kinetics in zebrafish. Similarly, microglia ablation enhances regenerative outcomes in the mouse retina. Targeted immunomodulation of microglia reactivity may therefore enhance the regenerative potential of M{\"u}ller glia for therapeutic purposes. Here, we investigated potential mechanisms by which post-injury dexamethasone accelerates retinal regeneration kinetics, and the effects of dendrimer-based targeting of dexamethasone to reactive microglia. Intravital time-lapse imaging revealed that post-injury dexamethasone inhibited microglia reactivity. The dendrimer-conjugated formulation: (1) decreased dexamethasone-associated systemic toxicity, (2) targeted dexamethasone to reactive microglia, and (3) improved the regeneration enhancing effects of immunosuppression by increasing stem/progenitor proliferation rates. Lastly, we show that the gene rnf2 is required for the enhanced regeneration effect of D-Dex. These data support the use of dendrimer-based targeting of reactive immune cells to reduce toxicity and enhance the regeneration promoting effects of immunosuppressants in the retina.

}, keywords = {Animals, Dendrimers, Dexamethasone, Immunosuppression Therapy, Mammals, Mice, Microglia, Retina, Zebrafish}, issn = {2399-3642}, doi = {10.1038/s42003-023-04898-9}, author = {Emmerich, Kevin and White, David T and Kambhampati, Siva P and Casado, Grace L and Fu, Tian-Ming and Chunawala, Zeeshaan and Sahoo, Arpan and Nimmagadda, Saumya and Krishnan, Nimisha and Saxena, Meera T and Walker, Steven L and Betzig, Eric and Kannan, Rangaramanujam M and Mumm, Jeff S} } @article {68675, title = {Origin of wiring specificity in an olfactory map revealed by neuron type-specific, time-lapse imaging of dendrite targeting.}, journal = {eLife}, volume = {12}, year = {2023}, month = {2023 Mar 28}, abstract = {

How does wiring specificity of neural maps emerge during development? Formation of the adult olfactory glomerular map begins with patterning of projection neuron (PN) dendrites at the early pupal stage. To better understand the origin of wiring specificity of this map, we created genetic tools to systematically characterize dendrite patterning across development at PN type-specific resolution. We find that PNs use lineage and birth order combinatorially to build the initial dendritic map. Specifically, birth order directs dendrite targeting in rotating and binary manners for PNs of the anterodorsal and lateral lineages, respectively. Two-photon- and adaptive optical lattice light-sheet microscope-based time-lapse imaging reveals that PN dendrites initiate active targeting with direction-dependent branch stabilization on the timescale of seconds. Moreover, PNs that are used in both the larval and adult olfactory circuits prune their larval-specific dendrites and re-extend new dendrites simultaneously to facilitate timely olfactory map organization. Our work highlights the power and necessity of type-specific neuronal access and time-lapse imaging in identifying wiring mechanisms that underlie complex patterns of functional neural maps.

}, issn = {2050-084X}, doi = {10.7554/eLife.85521}, author = {Wong, Kenneth Kin Lam and Li, Tongchao and Fu, Tian-Ming and Liu, Gaoxiang and Lyu, Cheng and Kohani, Sayeh and Xie, Qijing and Luginbuhl, David J and Upadhyayula, Srigokul and Betzig, Eric and Luo, Liqun} } @article {68690, title = {Sensitivity optimization of a rhodopsin-based fluorescent voltage indicator}, journal = {Neuron}, volume = {111}, year = {2023}, month = {2023 May 17}, pages = {1547-1563}, abstract = {

The ability to optically image cellular transmembrane voltages at millisecond-timescale resolutions can offer unprecedented insight into the function of living brains in behaving animals. Here, we present a\ point mutation\ that increases the sensitivity of Ace2 opsin-based voltage indicators. We use the mutation to develop Voltron2, an improved chemigeneic voltage indicator that has a 65\% higher sensitivity to single APs and 3-fold higher sensitivity to subthreshold potentials than Voltron. Voltron2 retained the sub-millisecond kinetics and photostability of its predecessor, although with lower baseline fluorescence. In multiple\ in\ vitro\ and\ in\ vivo\ comparisons with its predecessor across multiple species, we found Voltron2 to be more sensitive to APs and subthreshold fluctuations. Finally, we used Voltron2 to study and evaluate the possible mechanisms of\ interneuron\ synchronization in the mouse hippocampus. Overall, we have discovered a generalizable mutation that significantly increases the sensitivity of Ace2 rhodopsin-based sensors, improving their voltage reporting capability.

}, issn = {08966273}, doi = {10.1016/j.neuron.2023.03.009}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0896627323002052}, author = {Abdelfattah, Ahmed S. and Zheng, Jihong and Singh, Amrita and Huang, Yi-Chieh and Reep, Daniel and Tsegaye, Getahun and Tsang, Arthur and Arthur, Benjamin J. and Rehorova, Monika and Olson, Carl V.L. and Shuai, Yichun and Zhang, Lixia and Fu, Tian-Ming and Milkie, Daniel E. and Moya, Maria V. and Weber, Timothy D. and Lemire, Andrew L. and Baker, Christopher A. and Falco, Natalie and Zheng, Qinsi and Grimm, Jonathan B. and Yip, Mighten C. and Walpita, Deepika and Chase, Martin and Campagnola, Luke and Murphy, Gabe J. and Wong, Allan M. and Forest, Craig R. and Mertz, Jerome and Economo, Michael N. and Turner, Glenn C. and Koyama, Minoru and Lin, Bei-Jung and Betzig, Eric and Novak, Ondrej and Lavis, Luke D. and Svoboda, Karel and Korff, Wyatt and Chen, Tsai-Wen and Schreiter, Eric R. and Hasseman, Jeremy P. and Kolb, Ilya} } @article {68370, title = {A proliferative to invasive switch is mediated by srGAP1 downregulation through the activation of TGF-β2 signaling.}, journal = {Cell Reports}, volume = {40}, year = {2022}, month = {2022 Sep 20}, pages = {111358}, abstract = {

Many breast cancer (BC) patients suffer from complications of metastatic disease. To form metastases, cancer cells must become migratory and coordinate both invasive and proliferative programs at distant organs. Here, we identify srGAP1 as a regulator of a proliferative-to-invasive switch in BC cells. High-resolution light-sheet microscopy demonstrates that BC cells can form actin-rich protrusions during extravasation. srGAP1 cells display a motile and invasive phenotype that facilitates their extravasation from blood vessels, as shown in zebrafish and mouse models, while attenuating tumor growth. Interestingly, a population of srGAP1 cells remain as solitary disseminated tumor cells in the lungs of mice bearing BC tumors. Overall, srGAP1 cells have increased Smad2 activation and TGF-β2 secretion, resulting in increased invasion and p27 levels to sustain quiescence. These findings identify srGAP1 as a mediator of a proliferative to invasive phenotypic switch in BC cells in\ vivo through a TGF-β2-mediated signaling axis.

}, keywords = {Actins, Animals, Cell Line, Tumor, Down-Regulation, Mice, Transforming Growth Factor beta2, Zebrafish}, issn = {2211-1247}, doi = {10.1016/j.celrep.2022.111358}, author = {Mondal, Chandrani and Gacha-Garay, Majo J and Larkin, Kathryn A and Adikes, Rebecca C and Di Martino, Julie S and Chien, Chen-Chi and Fraser, Madison and Eni-Aganga, Ireti and Agullo-Pascual, Esperanza and Cialowicz, Katarzyna and Ozbek, Umut and Naba, Alexandra and Gaitas, Angelo and Fu, Tian-Ming and Upadhyayula, Srigokul and Betzig, Eric and Matus, David Q and Martin, Benjamin L and Bravo-Cordero, Jose Javier} } @article {67737, title = {Cellular bases of olfactory circuit assembly revealed by systematic time-lapse imaging.}, journal = {Cell}, volume = {184}, year = {2021}, month = {2021 Sep 30}, pages = {5107}, abstract = {

Neural circuit assembly features simultaneous targeting of numerous neuronal processes from constituent neuron types, yet the dynamics is poorly understood. Here, we use the Drosophila olfactory circuit to investigate dynamic cellular processes by which olfactory receptor neurons (ORNs) target axons precisely to specific glomeruli in the ipsi- and contralateral antennal lobes. Time-lapse imaging of individual axons from 30 ORN types revealed a rich diversity in extension speed, innervation timing, and ipsilateral branch locations and identified that ipsilateral targeting occurs via stabilization of transient interstitial branches. Fast imaging using adaptive optics-corrected lattice light-sheet microscopy showed that upon approaching target, many ORN types exhibiting "exploring branches" consisted of parallel microtubule-based terminal branches emanating from an F-actin-rich hub. Antennal nerve ablations uncovered essential roles for bilateral axons in contralateral target selection and for ORN axons to facilitate dendritic refinement of postsynaptic partner neurons. Altogether, these observations provide cellular bases for wiring specificity establishment.

}, issn = {1097-4172}, doi = {10.1016/j.cell.2021.08.030}, author = {Li, Tongchao and Fu, Tian-Ming and Wong, Kenneth Kin Lam and Li, Hongjie and Xie, Qijing and Luginbuhl, David J and Wagner, Mark J and Betzig, Eric and Luo, Liqun} }