scholarly journals In vivo deep-tissue microscopy with UCNP/Janus-dendrimers as imaging probes: resolution at depth and feasibility of ratiometric sensing

Nanoscale ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 2657-2672 ◽  
Author(s):  
Shane Plunkett ◽  
Mirna El Khatib ◽  
İkbal Şencan ◽  
Jason E. Porter ◽  
Anand T. N. Kumar ◽  
...  
Keyword(s):  
Energy Transfer ◽  
High Resolution ◽  
Excitation Energy Transfer ◽  
Deep Tissue ◽  
Ratiometric Sensing ◽  
Two Photon ◽  
Imaging Probes ◽  
Tissue Microscopy ◽  
The Brain

UCNP/Janus-dendrimers enable high-resolution two-photon imaging in the brain up to 1 mm-deep under low-power CW excitation. However, ratiometric sensing using UCNPs and excitation energy transfer is strongly obstructed by tissue absorption.

scholarly journals Ultrabright red AIEgens for two-photon vascular imaging with high resolution and deep penetration

2018 ◽  
Vol 9 (10) ◽  
pp. 2705-2710 ◽  
Author(s):  
Wei Qin ◽  
Pengfei Zhang ◽  
Hui Li ◽  
Jacky W. Y. Lam ◽  
Yuanjing Cai ◽  
...  
Keyword(s):  
High Resolution ◽  
Vascular Imaging ◽  
Tissue Imaging ◽  
Deep Penetration ◽  
High Contrast ◽  
Deep Tissue ◽  
Two Photon ◽  
High Penetration ◽  
Deep Tissue Imaging

A successful strategy for the design of ultrabright red luminogens with aggregation-induced emission (AIE) features is reported. The AIE dots can be utilized as efficient fluorescent probes for in vivo deep-tissue imaging with high penetration depth and high contrast.

scholarly journals The Power of Single and Multibeam Two-Photon Microscopy for High-Resolution and High-Speed Deep Tissue and Intravital Imaging

2007 ◽  
Vol 93 (7) ◽  
pp. 2519-2529 ◽  
Author(s):  
Raluca Niesner ◽  
Volker Andresen ◽  
Jens Neumann ◽  
Heinrich Spiecker ◽  
Matthias Gunzer
Keyword(s):  
High Resolution ◽  
High Speed ◽  
Intravital Imaging ◽  
Deep Tissue ◽  
Two Photon Microscopy ◽  
Two Photon

scholarly journals P02.08 Visualizing tumor cell - lymphocyte interactions in the brain metastatic cascade using in vivo two photon microscopy

2018 ◽  
Vol 20 (suppl_3) ◽  
pp. iii273-iii273
Author(s):  
M Piechutta ◽  
A S Berghoff ◽  
M A Karreman ◽  
K Gunkel ◽  
W Wick ◽  
...  
Keyword(s):  
Tumor Cell ◽  
Metastatic Cascade ◽  
Two Photon Microscopy ◽  
Two Photon ◽  
The Brain

scholarly journals Widespread inhibition, antagonism, and synergy in mouse olfactory sensory neurons in vivo

2019 ◽  
Author(s):  
Shigenori Inagaki ◽  
Ryo Iwata ◽  
Masakazu Iwamoto ◽  
Takeshi Imai
Keyword(s):  
Sensory Neurons ◽  
Calcium Imaging ◽  
Odorant Receptor ◽  
Sensory Information ◽  
Olfactory Sensory Neurons ◽  
Axon Terminals ◽  
Two Photon ◽  
Odor Mixtures ◽  
The Brain

SUMMARYSensory information is selectively or non-selectively inhibited and enhanced in the brain, but it remains unclear whether this occurs commonly at the peripheral stage. Here, we performed two-photon calcium imaging of mouse olfactory sensory neurons (OSNs) in vivo and found that odors produce not only excitatory but also inhibitory responses at their axon terminals. The inhibitory responses remained in mutant mice, in which all possible sources of presynaptic lateral inhibition were eliminated. Direct imaging of the olfactory epithelium revealed widespread inhibitory responses at OSN somata. The inhibition was in part due to inverse agonism toward the odorant receptor. We also found that responses to odor mixtures are often suppressed or enhanced in OSNs: Antagonism was dominant at higher odor concentrations, whereas synergy was more prominent at lower odor concentrations. Thus, odor responses are extensively tuned by inhibition, antagonism, and synergy, at the early peripheral stage, contributing to robust odor representations.

scholarly journals Microglia motility depends on neuronal activity and promotes structural plasticity in the hippocampus

2019 ◽  
Author(s):  
Felix C. Nebeling ◽  
Stefanie Poll ◽  
Lena C. Schmid ◽  
Manuel Mittag ◽  
Julia Steffen ◽  
...  
Keyword(s):  
Neuronal Activity ◽  
Dendritic Spines ◽  
Synapse Formation ◽  
Brain Parenchyma ◽  
Two Photon ◽  
Contact Rates ◽  
Health And Disease ◽  
The Impact ◽  
The Brain

AbstractMicroglia, the resident immune cells of the brain, play a complex role in health and disease. They actively survey the brain parenchyma by physically interacting with other cells and structurally shaping the brain. Yet, the mechanisms underlying microglia motility and their significance for synapse stability, especially during adulthood, remain widely unresolved. Here we investigated the impact of neuronal activity on microglia motility and its implication for synapse formation and survival. We used repetitive two-photon in vivo imaging in the hippocampus of awake mice to simultaneously study microglia motility and their interaction with synapses. We found that microglia process motility depended on neuronal activity. Simultaneously, more dendritic spines emerged in awake compared to anesthetized mice. Interestingly, microglia contact rates with individual dendritic spines were associated with their stability. These results suggest that microglia are not only sensing neuronal activity, but participate in synaptic rewiring of the hippocampus during adulthood, which has profound relevance for learning and memory processes.

Changes of Excitation Spectra of in vivo Chlorophyll Fluorescence during Induction of Photosynthesis

1993 ◽  
Vol 48 (1-2) ◽  
pp. 46-51 ◽  
Author(s):  
Wieslaw I. Gruszecki ◽  
Zbigniew Krupa
Keyword(s):  
Energy Transfer ◽  
Chlorophyll Fluorescence ◽  
Quantum Yield ◽  
Dark Adaptation ◽  
Fluorescence Quantum Yield ◽  
Excitation Energy Transfer ◽  
Reaction Centers ◽  
Excitation Spectra ◽  
In Vivo Chlorophyll Fluorescence

Excitation spectra of chlorophyll fluorescence from intact rye leaves were registered at different steps of the induction of photosynthesis after dark adaptation. Analysis of these spectra indicates that at least two processes related to spectroscopic features are responsible for a fluorescence quenching. The first one, active during the first 100 s of illumination, was interpreted to consists in an overall decrease of the fluorescence quantum yield of antenna pigments and chlorophylls, in particular close to the reaction centers. The second type of a fluorescence decrease (between 100 s and 300 s of illumination) was found to be in large extent related to decrease of the rate of an excitation energy transfer between accessory xanthophyll pigments and chlorophylls emitting fluorescence. This latter molecular mechanism is discussed as being related to violaxanthin availability to de-epoxidation in the xanthophyll cycle.

scholarly journals Efficient implementation of convolutional neural networks in the data processing of two-photon in vivo imaging

2019 ◽  
Vol 35 (17) ◽  
pp. 3208-3210 ◽  
Author(s):  
Yangzhen Wang ◽  
Feng Su ◽  
Shanshan Wang ◽  
Chaojuan Yang ◽  
Yonglu Tian ◽  
...  
Keyword(s):  
Neural Networks ◽  
Convolutional Neural Networks ◽  
Detection Methods ◽  
Supplementary Information ◽  
Imaging Data ◽  
Two Photon ◽  
Processing Power ◽  
Fluctuation Method ◽  
The Brain

Abstract Motivation Functional imaging at single-neuron resolution offers a highly efficient tool for studying the functional connectomics in the brain. However, mainstream neuron-detection methods focus on either the morphologies or activities of neurons, which may lead to the extraction of incomplete information and which may heavily rely on the experience of the experimenters. Results We developed a convolutional neural networks and fluctuation method-based toolbox (ImageCN) to increase the processing power of calcium imaging data. To evaluate the performance of ImageCN, nine different imaging datasets were recorded from awake mouse brains. ImageCN demonstrated superior neuron-detection performance when compared with other algorithms. Furthermore, ImageCN does not require sophisticated training for users. Availability and implementation ImageCN is implemented in MATLAB. The source code and documentation are available at https://github.com/ZhangChenLab/ImageCN. Supplementary information Supplementary data are available at Bioinformatics online.

scholarly journals IMMU-26. VISUALIZING TUMOR CELL - LYMPHOCYTE INTERACTIONS IN THE BRAIN METASTATIC CASCADE USING IN VIVO TWO PHOTON MICROSCOPY

2018 ◽  
Vol 20 (suppl_6) ◽  
pp. vi126-vi127
Author(s):  
Manuel Piechutta ◽  
Anna Berghoff ◽  
Matthia Karreman ◽  
Katharina Gunkel ◽  
Wolfgang Wick ◽  
...  
Keyword(s):  
Tumor Cell ◽  
Metastatic Cascade ◽  
Two Photon Microscopy ◽  
Two Photon ◽  
The Brain

Recent advances in molecular imaging probes for β-amyloid plaques

MedChemComm ◽  
2015 ◽  
Vol 6 (3) ◽  
pp. 391-402 ◽  
Author(s):  
Masahiro Ono ◽  
Hideo Saji
Keyword(s):  
Molecular Imaging ◽  
Optical Imaging ◽  
Amyloid Plaques ◽  
Recent Advances ◽  
Molecular Imaging Probes ◽  
Imaging Probes ◽  
Β Amyloid ◽  
The Brain

We review recent advances in our development of molecular imaging probes for PET, SPECT, and optical imaging for in vivo detection of β-amyloid plaques in the brain.

scholarly journals Spatial Distribution and Function of Sterol Regulatory Element-Binding Protein 1a and 2 Homo- and Heterodimers by In Vivo Two-Photon Imaging and Spectroscopy Fluorescence Resonance Energy Transfer

2005 ◽  
Vol 25 (8) ◽  
pp. 2946-2956 ◽  
Author(s):  
Aikaterini Zoumi ◽  
Shrimati Datta ◽  
Lih-Huei L. Liaw ◽  
Cristen J. Wu ◽  
Gopi Manthripragada ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Fluorescence Resonance Energy Transfer ◽  
Regulatory Element ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Two Photon ◽  
Sterol Regulatory Element ◽  
Photon Imaging ◽  
Imaging And Spectroscopy

ABSTRACT Sterol regulatory element-binding proteins (SREBPs) are a subfamily of basic helix-loop-helix-leucine zipper proteins that regulate lipid metabolism. We show novel evidence of the in vivo occurrence and subnuclear spatial localization of both exogenously expressed SREBP-1a and -2 homodimers and heterodimers obtained by two-photon imaging and spectroscopy fluorescence resonance energy transfer. SREBP-1a homodimers localize diffusely in the nucleus, whereas SREBP-2 homodimers and the SREBP-1a/SREBP-2 heterodimer localize predominantly to nuclear speckles or foci, with some cells showing a diffuse pattern. We also used tethered SREBP dimers to demonstrate that both homo- and heterodimeric SREBPs activate transcription in vivo. Ultrastructural analysis revealed that the punctate foci containing SREBP-2 are electron-dense nuclear bodies, similar or identical to structures containing the promyelocyte (PML) protein. Immunofluorescence studies suggest that a dynamic interplay exists between PML, as well as another component of the PML-containing nuclear body, SUMO-1, and SREBP-2 within these nuclear structures. These findings provide new insight into the overall process of transcriptional activation mediated by the SREBP family.

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