scholarly journals Three-photon imaging of synthetic dyes in deep layers of the neocortex

2020 ◽  
Author(s):  
Chao J. Liu ◽  
Arani Roy ◽  
Anthony A. Simons ◽  
Deano M. Farinella ◽  
Prakash Kara
Keyword(s):  
Multiphoton Microscopy ◽  
Synthetic Dyes ◽  
Visual Responses ◽  
Cortical Layers ◽  
Imaging Tool ◽  
Functional Dynamics ◽  
Calcium Indicator ◽  
Deep Layers ◽  
Photon Imaging

AbstractMultiphoton microscopy has emerged as the primary imaging tool for studying the structural and functional dynamics of neural circuits in brain tissue, which is highly scattering to light. Recently, three-photon microscopy has enabled high-resolution fluorescence imaging of neurons in deeper brain areas that lie beyond the reach of conventional two-photon microscopy, which is typically limited to ~450 μm. Three-photon imaging of neuronal calcium signals, through the genetically-encoded calcium indicator GCaMP6, has been used to successfully record neuronal activity in deeper neocortical layers and parts of the hippocampus. Bulk-loading cells in deeper cortical layers with synthetic calcium indicators could provide an alternative strategy for labelling that obviates dependence on viral tropism and promoter penetration. Here we report a strategy for visualized injection of a calcium dye, Oregon Green BAPTA-1 AM (OGB-1 AM), at 500–600 μm below the surface of the mouse visual cortex in vivo. We demonstrate successful OGB-1 AM loading of cells in cortical layers 5–6 and subsequent three-photon imaging of orientation- and direction-selective visual responses from these cells.

scholarly journals Three-photon imaging of synthetic dyes in deep layers of the neocortex

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Chao J. Liu ◽  
Arani Roy ◽  
Anthony A. Simons ◽  
Deano M. Farinella ◽  
Prakash Kara
Keyword(s):  
Multiphoton Microscopy ◽  
Synthetic Dyes ◽  
Visual Responses ◽  
Cortical Layers ◽  
Imaging Tool ◽  
Functional Dynamics ◽  
Calcium Indicator ◽  
Deep Layers ◽  
Photon Imaging

Abstract Multiphoton microscopy has emerged as the primary imaging tool for studying the structural and functional dynamics of neural circuits in brain tissue, which is highly scattering to light. Recently, three-photon microscopy has enabled high-resolution fluorescence imaging of neurons in deeper brain areas that lie beyond the reach of conventional two-photon microscopy, which is typically limited to ~ 450 µm. Three-photon imaging of neuronal calcium signals, through the genetically-encoded calcium indicator GCaMP6, has been used to successfully record neuronal activity in deeper neocortical layers and parts of the hippocampus in rodents. Bulk-loading cells in deeper cortical layers with synthetic calcium indicators could provide an alternative strategy for labelling that obviates dependence on viral tropism and promoter penetration, particularly in non-rodent species. Here we report a strategy for visualized injection of a calcium dye, Oregon Green BAPTA-1 AM (OGB-1 AM), at 500–600 µm below the surface of the mouse visual cortex in vivo. We demonstrate successful OGB-1 AM loading of cells in cortical layers 5–6 and subsequent three-photon imaging of orientation- and direction- selective visual responses from these cells.

scholarly journals In vivo multiphoton microscopy of cardiomyocyte calcium dynamics in the beating mouse heart

2018 ◽  
Author(s):  
Jason S. Jones ◽  
David M. Small ◽  
Nozomi Nishimura
Keyword(s):  
Action Potentials ◽  
Multiphoton Microscopy ◽  
Three Dimensional ◽  
Heart Beat ◽  
Beating Heart ◽  
Mouse Heart ◽  
Calcium Dynamics ◽  
Intact Mouse ◽  
Calcium Indicator

AbstractWe demonstrated intravital multiphoton microscopy in the beating heart in an intact mouse and optically measured action potentials with GCaMP6f, a genetically-encoded calcium indicator. Images were acquired at 30 fps with spontaneous heart beat and continuously running ventilated breathing. The data were reconstructed into three-dimensional volumes showing tissue structure, displacement, and GCaMP activity in cardiomyocytes as a function of both the cardiac and respiratory cycle.

scholarly journals Thy1transgenic mice expressing the red fluorescent calcium indicator jRGECO1a for neuronal population imagingin vivo

2018 ◽  
Author(s):  
Hod Dana ◽  
Ondrej Novak ◽  
Michael Guardado-Montesino ◽  
James W. Fransen ◽  
Amy Hu ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Ganglion Cells ◽  
Signal To Noise Ratio ◽  
Expression Patterns ◽  
Neuronal Population ◽  
Viral Gene ◽  
Visual Responses ◽  
Calcium Indicator ◽  
Transgenic Lines

AbstractCalcium imaging is commonly used to measure the neural activity of large groups of neurons in mice. Genetically encoded calcium indicators (GECIs) can be delivered for this purpose using non-invasive genetic methods. Compared to viral gene transfer, transgenic targeting of GECIs provides stable long-term expression and obviates the need for invasive viral injections. Transgenic mice expressing the green GECI GCaMP6 are already widely used. Here we present the generation and characterizarion of transgenic mice expressing the sensitive red GECI jRGECO1a, driven by theThy1promoter. Four transgenic lines with different expression patterns showed sufficiently high expression for cellularin vivoimaging. We used two-photon microscopy to characterize visual responses of individual neurons in the visual cortexin vivo. The signal-to-noise ratio in transgenic mice was comparable to, or better than, for mice transduced with adeno-associated virus. We also show thatThy1-jRGECO1a transgenic mice are useful for transcranial population imaging and functional mapping using widefield fluorescecnce microscopy. We also demonstrate imaging of visual responses in retinal ganglion cells.Thy1-jRGECO1a transgenic mice are therefore a useful addition to the toolbox for imaging activity in intact neural networks.

A genetically encoded calcium indicator for chronic in vivo two-photon imaging

2008 ◽  
Vol 5 (9) ◽  
pp. 805-811 ◽  
Author(s):  
Marco Mank ◽  
Alexandre Ferrão Santos ◽  
Stephan Direnberger ◽  
Thomas D Mrsic-Flogel ◽  
Sonja B Hofer ◽  
...  
Keyword(s):  
Two Photon ◽  
Calcium Indicator ◽  
Photon Imaging ◽  
Two Photon Imaging

In Vivo Deep-Brain Structural and Hemodynamic Multiphoton Microscopy Enabled by Quantum Dots

Nano Letters ◽  
2019 ◽  
Vol 19 (8) ◽  
pp. 5260-5265 ◽  
Author(s):  
Hongji Liu ◽  
Xiangquan Deng ◽  
Shen Tong ◽  
Chen He ◽  
Hui Cheng ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Multiphoton Microscopy ◽  
Deep Brain

scholarly journals Preclinical Evaluation of [18F]FACH in Healthy Mice and Piglets: An 18F-Labeled Ligand for Imaging of Monocarboxylate Transporters with PET

2021 ◽  
Vol 22 (4) ◽  
pp. 1645
Author(s):  
Daniel Gündel ◽  
Masoud Sadeghzadeh ◽  
Winnie Deuther-Conrad ◽  
Barbara Wenzel ◽  
Paul Cumming ◽  
...  
Keyword(s):  
Molecular Imaging ◽  
Ex Vivo ◽  
Specific Binding ◽  
Monocarboxylate Transporters ◽  
Binding Potential ◽  
Kidney Cortex ◽  
Binding Studies ◽  
Imaging Tool ◽  
Pre Treatment

The expression of monocarboxylate transporters (MCTs) is linked to pathophysiological changes in diseases, including cancer, such that MCTs could potentially serve as diagnostic markers or therapeutic targets. We recently developed [18F]FACH as a radiotracer for non-invasive molecular imaging of MCTs by positron emission tomography (PET). The aim of this study was to evaluate further the specificity, metabolic stability, and pharmacokinetics of [18F]FACH in healthy mice and piglets. We measured the [18F]FACH plasma protein binding fractions in mice and piglets and the specific binding in cryosections of murine kidney and lung. The biodistribution of [18F]FACH was evaluated by tissue sampling ex vivo and by dynamic PET/MRI in vivo, with and without pre-treatment by the MCT inhibitor α-CCA-Na or the reference compound, FACH-Na. Additionally, we performed compartmental modelling of the PET signal in kidney cortex and liver. Saturation binding studies in kidney cortex cryosections indicated a KD of 118 ± 12 nM and Bmax of 6.0 pmol/mg wet weight. The specificity of [18F]FACH uptake in the kidney cortex was confirmed in vivo by reductions in AUC0–60min after pre-treatment with α-CCA-Na in mice (−47%) and in piglets (−66%). [18F]FACH was metabolically stable in mouse, but polar radio-metabolites were present in plasma and tissues of piglets. The [18F]FACH binding potential (BPND) in the kidney cortex was approximately 1.3 in mice. The MCT1 specificity of [18F]FACH uptake was confirmed by displacement studies in 4T1 cells. [18F]FACH has suitable properties for the detection of the MCTs in kidney, and thus has potential as a molecular imaging tool for MCT-related pathologies, which should next be assessed in relevant disease models.

scholarly journals Mannan-Based Nanodiagnostic Agents for Targeting Sentinel Lymph Nodes and Tumors

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 146
Author(s):  
Markéta Jirátová ◽  
Andrea Gálisová ◽  
Maria Rabyk ◽  
Eva Sticová ◽  
Martin Hrubý ◽  
...  
Keyword(s):  
Lymph Nodes ◽  
Intraoperative Imaging ◽  
Tumor Model ◽  
Intercellular Adhesion Molecule ◽  
Internal Organs ◽  
Polymer Carriers ◽  
Polymer Conjugates ◽  
Imaging Tool ◽  
Imaging Probes

Early detection of metastasis is crucial for successful cancer treatment. Sentinel lymph node (SLN) biopsies are used to detect possible pathways of metastasis spread. We present a unique non-invasive diagnostic alternative to biopsy along with an intraoperative imaging tool for surgery proven on an in vivo animal tumor model. Our approach is based on mannan-based copolymers synergistically targeting: (1) SLNs and macrophage-infiltrated solid tumor areas via the high-affinity DC-SIGN (dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin) receptors and (2) tumors via the enhanced permeability and retention (EPR) effect. The polymer conjugates were modified with the imaging probes for visualization with magnetic resonance (MR) and fluorescence imaging, respectively, and with poly(2-methyl-2-oxazoline) (POX) to lower unwanted accumulation in internal organs and to slow down the biodegradation rate. We demonstrated that these polymer conjugates were successfully accumulated in tumors, SLNs and other lymph nodes. Modification with POX resulted in lower accumulation not only in internal organs, but also in lymph nodes and tumors. Importantly, we have shown that mannan-based polymer carriers are non-toxic and, when applied to an in vivo murine cancer model, and offer promising potential as the versatile imaging agents.

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