scholarly journals Miniature Structured Illumination Microscope for in vivo 3D Imaging of Brain Structures with Optical Sectioning

2021 ◽  
Author(s):  
Omkar D. Supekar ◽  
Andrew Sias ◽  
Sean R. Hansen ◽  
Gabriel Martinez ◽  
Graham C. Peet ◽  
...  
Keyword(s):  
High Resolution ◽  
3D Imaging ◽  
Scattered Light ◽  
Brain Structures ◽  
Structured Illumination ◽  
Optical Sectioning ◽  
Recording Time ◽  
Volumetric Imaging ◽  
The Brain

AbstractWe present a high-resolution miniature, light-weight fluorescence microscope with electrowetting lens and onboard CMOS for high resolution volumetric imaging and structured illumination for rejection of out-of-focus and scattered light. The miniature microscope (SIMscope3D) delivers structured light using a coherent fiber bundle to obtain optical sectioning with an axial resolution of 18 μm. Volumetric imaging of eGFP labeled cells in fixed mouse brain tissue at depths up to 220 μm is demonstrated. The functionality of SIMscope3D to provide background free 3D imaging is shown by recording time series of microglia dynamics in awake mice at depths up to 120 μm in the brain.

scholarly journals A New Method to Measure Brain Serotonin Synthesis in vivo. I. Theory and Basic Data for a Biological Model

1990 ◽  
Vol 10 (1) ◽  
pp. 1-12 ◽  
Author(s):  
M. Diksic ◽  
S. Nagahiro ◽  
T. L. Sourkes ◽  
Y. L. Yamamoto
Keyword(s):  
Trichloroacetic Acid ◽  
Brain Slices ◽  
Brain Structures ◽  
Pineal Body ◽  
Biological Model ◽  
Tracer Kinetics ◽  
Serotonin Synthesis ◽  
Precursor Pool ◽  
The Brain

We describe here an autoradiographic method to measure the in vivo rate of serotonin synthesis in rat brain. The method is based on the use of the l-tryptophan analogue a-methyl-l-tryptophan ( a-MTrp), which is converted in vivo into a-methylserotonin ( a-M5HT). Since a-M5HT is not a substrate for monoamine oxidase, it is accumulated in the brain tissue. Data are presented to confirm time-dependent conversion of a-MTrp into a-M5HT in the dorsal raphe nucleus and also in the pineal body, an organ outside the blood–brain barrier. It has also been shown that washing brain slices in 10% trichloroacetic acid results in <3% incorporation of a-MTrp into brain proteins. The rates of synthesis are calculated in several grossly dissected brain structures by using tracer kinetics and a three-compartment biological model. The half-life of the precursor pool is estimated to be ∼20 min. The rate of serotonin synthesis is highest in the pineal body.

scholarly journals Differential structured illumination microendoscopy for in vivo imaging of molecular contrast agents

2016 ◽  
Vol 113 (39) ◽  
pp. 10769-10773 ◽  
Author(s):  
Pelham Keahey ◽  
Preetha Ramalingam ◽  
Kathleen Schmeler ◽  
Rebecca R. Richards-Kortum
Keyword(s):  
Contrast Agents ◽  
In Vivo Imaging ◽  
Fiber Optic ◽  
Adenocarcinoma In Situ ◽  
Structured Illumination ◽  
Optical Sectioning ◽  
Optical Elements ◽  
Fiber Optic System ◽  
Molecular Contrast

Fiber optic microendoscopy has shown promise for visualization of molecular contrast agents used to study disease in vivo. However, fiber optic microendoscopes have limited optical sectioning capability, and image contrast is limited by out-of-focus light generated in highly scattering tissue. Optical sectioning techniques have been used in microendoscopes to remove out-of-focus light but reduce imaging speed or rely on bulky optical elements that prevent in vivo imaging. Here, we present differential structured illumination microendoscopy (DSIMe), a fiber optic system that can perform structured illumination in real time for optical sectioning without any opto-mechanical components attached to the distal tip of the fiber bundle. We demonstrate the use of DSIMe during in vivo fluorescence imaging in patients undergoing surgery for cervical adenocarcinoma in situ. Images acquired using DSIMe show greater contrast than standard microendoscopy, improving the ability to detect cellular atypia associated with neoplasia.

scholarly journals Imaging tissues and cells beyond the diffraction limit with structured illumination microscopy and Bayesian image reconstruction

2018 ◽  
Author(s):  
Jakub Pospíšil ◽  
Tomáš Lukeš ◽  
Justin Bendesky ◽  
Karel Fliegel ◽  
Kathrin Spendier ◽  
...  
Keyword(s):  
High Resolution ◽  
Open Source ◽  
Fluorescent Protein ◽  
Super Resolution ◽  
Live Cells ◽  
Structured Illumination ◽  
Optical Sectioning ◽  
Structured Illumination Microscopy ◽  
Raw Data ◽  
Bayesian Image Reconstruction

AbstractBackgroundStructured illumination microscopy (SIM) is a family of methods in optical fluorescence microscopy that can achieve both optical sectioning and super-resolution effects. SIM is a valuable method for high resolution imaging of fixed cells or tissues labeled with conventional fluorophores, as well as for imaging the dynamics of live cells expressing fluorescent protein constructs. In SIM, one acquires a set of images with shifting illumination patterns. This set of images is subsequently treated with image analysis algorithms to produce an image with reduced out-of-focus light (optical sectioning) and/or with improved resolution (super-resolution).FindingsFive complete and freely available SIM datasets are presented including raw and analyzed data. We report methods for image acquisition and analysis using open source software along with examples of the resulting images when processed with different methods. We processed the data using established optical sectioning SIM and super-resolution SIM methods, and with newer Bayesian restoration approaches which we are developing.ConclusionVarious methods for SIM data acquisition and processing are actively being developed, but complete raw data from SIM experiments is not typically published. Publicly available, high quality raw data with examples of processed results will aid researchers when developing new methods in SIM. Biologists will also find interest in the high-resolution images of animal tissues and cells we acquired. All of the data was processed with SIMToolbox, an open source and freely available software solution for SIM.

scholarly journals Motion-Correction Enabled Ultra-High Resolution In-Vivo 7T-MRI of the Brain

PLoS ONE ◽  
2016 ◽  
Vol 11 (5) ◽  
pp. e0154974 ◽  
Author(s):  
Christian Federau ◽  
Daniel Gallichan
Keyword(s):  
High Resolution ◽  
Motion Correction ◽  
The Brain

scholarly journals High-resolution in vivo optical-sectioning widefield microendoscopy

Optica ◽  
2020 ◽  
Vol 7 (10) ◽  
pp. 1287
Author(s):  
Qinrong Zhang ◽  
Daisong Pan ◽  
Na Ji
Keyword(s):  
High Resolution ◽  
Optical Sectioning

scholarly journals HiLo Based Line Scanning Temporal Focusing Microscopy for High-Speed, Deep Tissue Imaging

Membranes ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 634
Author(s):  
Ruheng Shi ◽  
Yuanlong Zhang ◽  
Tiankuang Zhou ◽  
Lingjie Kong
Keyword(s):  
High Speed ◽  
Three Dimensions ◽  
Tissue Imaging ◽  
Deep Penetration ◽  
High Temporal Resolution ◽  
Structured Illumination ◽  
Volumetric Imaging ◽  
Temporal Focusing ◽  
Line Scanning

High-speed, optical-sectioning imaging is highly desired in biomedical studies, as most bio-structures and bio-dynamics are in three-dimensions. Compared to point-scanning techniques, line scanning temporal focusing microscopy (LSTFM) is a promising method that can achieve high temporal resolution while maintaining a deep penetration depth. However, the contrast and axial confinement would still be deteriorated in scattering tissue imaging. Here, we propose a HiLo-based LSTFM, utilizing structured illumination to inhibit the fluorescence background and, thus, enhance the image contrast and axial confinement in deep imaging. We demonstrate the superiority of our method by performing volumetric imaging of neurons and dynamical imaging of microglia in mouse brains in vivo.

scholarly journals In vivo Binding of Nimodipine in the Brain: I. The Effect of Focal Cerebral Ischemia

1991 ◽  
Vol 11 (5) ◽  
pp. 762-770 ◽  
Author(s):  
Antoine M. Hakim ◽  
Matthew J. Hogan
Keyword(s):  
Cerebral Ischemia ◽  
Striate Cortex ◽  
Focal Cerebral Ischemia ◽  
Brain Structures ◽  
Significant Rise ◽  
Secular Equilibrium ◽  
Control Right ◽  
And Control ◽  
The Brain

We report the regional variation in [3H]nimodipine binding in vivo during focal cerebral ischemia. After intravenous injection, 30 min of circulation of [3H]nimodipine was sufficient to establish a secular equilibrium of distribution in the brain. Rats sustained left middle cerebral and common carotid artery occlusions for 5 min, and 4, 24, and 48 h (n ≥ 6 per group). They were decapitated 30 min after injection of 250 μCi of [3H]nimodipine and their brains were submitted to autoradiography. The concentrations of [3H]nimodipine in plasma and brain structures, corrected for metabolism of nimodipine, were used to calculate the regional volumes of distribution ( V) in the ischemic left (L) and control right (R) hemispheres. Log (VL/VR) was then defined as the group mean of the logarithms of the left-to-right ratio of V of [3H]nimodipine. In the lateral caudate, binding of [3H]nimodipine on the ischemic side was highest within 5 min of occlusion. Log ( VL/ VR) in this region for the combined sham-operated and normal control rats and those after 5 min and 4 and 24 h of ischemia were −0.014 ± 0.025, 0.137 ± 0.056*, −0.201 ± 0.367, and −0.049 ± 0.370 (mean ± SD, *represents p < 0.01 compared with controls). By contrast, in the superior frontal cortex, values for log ( VL/ VR) in the same sequence were −0.016 ± 0.025, 0.028 ± 0.056, 0.284 ± 0.228*, and 0.224 ± 0.069*, thus showing a significant rise in [3H]nimodipine binding only at 4 h. Structures such as the cingulate and striate cortex, sufficiently removed from the ischemic core, showed only small changes in log ( VL/ VR) at all times. Correlating these data with CBF and histologic determinations performed in separate groups of rats, we conclude that [3H]nimodipine binding increases earlier in the more severely ischemic structures than in those with more moderate reductions in perfusion. Furthermore, when binding declines in a region where it was previously increased, infarction is likely. These studies afford new insight into the concept of ischemic penumbra and suggest that this model may allow testing for therapeutic effectiveness.

scholarly journals Spatio-temporal dynamics of cerebral capillary segments with stalling red blood cells

2017 ◽  
Vol 39 (5) ◽  
pp. 886-900 ◽  
Author(s):  
Şefik Evren Erdener ◽  
Jianbo Tang ◽  
Amir Sajjadi ◽  
Kıvılcım Kılıç ◽  
Sreekanth Kura ◽  
...  
Keyword(s):  
Temporal Dynamics ◽  
Oct Angiography ◽  
Label Free ◽  
Systematic Analysis ◽  
Volumetric Imaging ◽  
Cerebral Capillary ◽  
Spatio Temporal ◽  
The Brain

Optical coherence tomography (OCT) allows label-free imaging of red blood cell (RBC) flux within capillaries with high spatio-temporal resolution. In this study, we utilized time-series OCT-angiography to demonstrate interruptions in capillary RBC flux in mouse brain in vivo. We noticed ∼7.5% of ∼200 capillaries had at least one stall in awake mice with chronic windows during a 9-min recording. At any instant, ∼0.45% of capillaries were stalled. Average stall duration was ∼15 s but could last over 1 min. Stalls were more frequent and longer lasting in acute window preparations. Further, isoflurane anesthesia in chronic preparations caused an increase in the number of stalls. In repeated imaging, the same segments had a tendency to stall again over a period of one month. In awake animals, functional stimulation decreased the observance of stalling events. Stalling segments were located distally, away from the first couple of arteriolar-side capillary branches and their average RBC and plasma velocities were lower than nonstalling capillaries within the same region. This first systematic analysis of capillary RBC stalls in the brain, enabled by rapid and continuous volumetric imaging of capillaries with OCT-angiography, will lead to future investigations of the potential role of stalling events in cerebral pathologies.

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