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multiphoton imaging

Renaud Schuck, Mary Ann Go, Stefania Garasto, Stephanie Reynolds, Pier Luigi Dragotti, Simon Schultz
OBJECTIVE: Multi-photon laser scanning microscopy provides a powerful tool for monitoring the spatiotemporal dynamics of neural circuit activity. It is, however, intrinsically a point scanning technique. Standard raster scanning enables imaging at subcellular resolution; however, acquisition rates are limited by the size of the field of view to be scanned. Recently developed scanning strategies such as Travelling Salesman Scanning (TSS) have been developed to maximize cellular sampling rate by scanning only select regions in the field of view corresponding to locations of interest such as somata...
November 13, 2017: Journal of Neural Engineering
Oliver J Muensterer, Sibylle Waldron, Yoon Jung Boo, Claudius Ries, Lisa Sehls, Frank Simon, Larissa Seidmann, Jérôme Birkenstock, Jan Gödeke
BACKGROUND: The prognosis of solid pediatric tumors strongly correlates with accurate staging and complete local control. Currently, surgeons rely on macroscopic cues and intraoperative cryosection to determine resection borders. Multiphoton Microscopy (MPM) is a real time technique that allows imaging of tissue without time-consuming tissue processing. PURPOSE: This pilot study evaluates the diagnostic potential of MPM in pediatric solid tumors compared to routine histopathology...
October 30, 2017: International Journal of Surgery
Karl J Lewis, Dorra Frikha-Benayed, Joyce Louie, Samuel Stephen, David C Spray, Mia M Thi, Zeynep Seref-Ferlengez, Robert J Majeska, Sheldon Weinbaum, Mitchell B Schaffler
Osteocytes are considered to be the major mechanosensory cells of bone, but how osteocytes in vivo process, perceive, and respond to mechanical loading remains poorly understood. Intracellular calcium (Ca(2+)) signaling resulting from mechanical stimulation has been widely studied in osteocytes in vitro and in bone explants, but has yet to be examined in vivo. This is achieved herein by using a three-point bending device which is capable of delivering well-defined mechanical loads to metatarsal bones of living mice while simultaneously monitoring the intracellular Ca(2+) responses of individual osteocytes by using a genetically encoded fluorescent Ca(2+) indicator...
October 31, 2017: Proceedings of the National Academy of Sciences of the United States of America
Maximilian J Waldner, Timo Rath, Sebastian Schürmann, Christian Bojarski, Raja Atreya
In recent years, various technological developments markedly improved imaging of mucosal inflammation in patients with inflammatory bowel diseases. Although technological developments such as high-definition-, chromo-, and autofluorescence-endoscopy led to a more precise and detailed assessment of mucosal inflammation during wide-field endoscopy, probe-based and stationary confocal laser microscopy enabled in vivo real-time microscopic imaging of mucosal surfaces within the gastrointestinal tract. Through the use of fluorochromes with specificity against a defined molecular target combined with endoscopic techniques that allow ultrastructural resolution, molecular imaging enables in vivo visualization of single molecules or receptors during endoscopy...
2017: Frontiers in Immunology
Jenelle L Wallace, Martin Wienisch, Venkatesh N Murthy
New neurons appear only in a few regions of the adult mammalian brain and become integrated into existing circuits. Little is known about the functional development of individual neurons in vivo. We examined the functional life history of adult-born granule cells (abGCs) in the olfactory bulb using multiphoton imaging in awake and anesthetized mice. We found that abGCs can become responsive to odorants soon after they arrive in the olfactory bulb. Tracking identified abGCs over weeks revealed that the robust and broadly tuned responses of most newly arrived abGCs gradually become more selective over a period of ∼3 weeks, but a small fraction achieves broader tuning with maturation...
November 15, 2017: Neuron
Shaun Pacheco, Chengliang Wang, Monica K Chawla, Minhkhoi Nguyen, Brend K Baggett, Urs Utzinger, Carol A Barnes, Rongguang Liang
Confocal fluorescence microscopy is often used in brain imaging experiments, however conventional confocal microscopes are limited in their field of view, working distance, and speed for high resolution imaging. We report here the development of a novel high resolution, high speed, long working distance, and large field of view confocal fluorescence microscope (H(2)L(2)-CFM) with the capability of multi-region and multifocal imaging. To demonstrate the concept, a 0.5 numerical aperture (NA) confocal fluorescence microscope is prototyped with a 3 mm × 3 mm field of view and 12 mm working distance, an array of 9 beams is scanned over the field of view in 9 different regions to speed up the acquisition time by a factor of 9...
October 17, 2017: Scientific Reports
Babak Amirsolaimani, Benjamin Cromey, N Peyghambarian, Khanh Kieu
We present the design, construction, and characterization of a multiphoton microscope that uses reflective elements for beam shaping and steering. This compact all reflective design removes the adverse effects of dispersion on laser pulse broadening as well as chromatic aberration in the focusing of broadband and multicolored laser sources. The design of this system is discussed in detail, including aberrations analysis via ray-tracing simulation and opto-mechanical design. The resolution of this mirror based all-reflective microscope is characterized using fluorescent microbeads...
September 18, 2017: Optics Express
Genevieve Vigil, Yide Zhang, Aamir Khan, Scott Howard
Here we recount the standard two-level model that describes saturated excitation (SAX) in multiphoton microscopy (MPM), a new technique for super-resolution fluorescence microscopy in scattering tissue, which requires no special chemistry and only simple modifications to a commercial MPM microscope. We use the model to study conditions required for improvements in MPM SAX resolution and experimental implementation strategies. Simulation results find zeros, or nodes, in the frequency response, which generate highly irregular point-spread functions (PSFs), such as rings and ripples, that contain spatial frequency content >3× larger than allowed by diffraction...
July 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
Zsuzsanna Heiner, Ingrid Zeise, Rivka Elbaum, Janina Kneipp
Spontaneous Raman scattering microspectrocopy, second harmonic generation (SHG), and two-photon excited fluorescence (2PF) were used in combination to characterize the morphology together with the chemical composition of the cell wall in native plant tissues. As the data obtained with unstained sections of Sorghum bicolor root and leaf tissues illustrate, non-resonant as well as pre-resonant Raman microscopy in combination with hyperspectral analysis reveals details about the distribution and composition of the major cell wall constituents...
October 12, 2017: Journal of Biophotonics
Gabrielle A Murashova, Christopher A Mancuso, Sanae Sakami, Krzysztof Palczewski, Grazyna Palczewska, Marcos Dantus
In this work, we present all epi-direction detected images of an unstained mouse retina using multiphoton microscopy with a sub-50 fs Yb-fiber laser centered at 1.07 μm. This wavelength is particularly interesting as the fundamental wavelength is transparent to the anterior segment of the eye and the higher harmonics are above DNA-damaging UV wavelengths. We present a characterization of the multimodal signals emitted from the different retinal layers, as well as from the choroid and the sclera. By characterizing native multiphoton signals from the retina, we move closer to having Yb-fiber considered for in vivo diagnosis of retinal disease through multiphoton microscopy as well as for corrective therapies...
March 2017: Proceedings of SPIE
Vasileios Askoxylakis, Mark Badeaux, Sylvie Roberge, Ana Batista, Ned Kirkpatrick, Matija Snuderl, Zohreh Amoozgar, Giorgio Seano, Gino B Ferraro, Sampurna Chatterjee, Lei Xu, Dai Fukumura, Dan G Duda, Rakesh K Jain
The cerebellum is a prominent part of the vertebrate hindbrain that is critically involved in the regulation of important body functions such as movement coordination, maintenance of balance and posture, and motor control. Here, we describe a cerebellar window that provides access to the mouse cerebellum for intravital imaging, thereby allowing for a detailed characterization of the dynamic processes in this region of the brain. First, the skull overlying the cerebellum is removed, and then the window is applied to the region of interest...
November 2017: Nature Protocols
Alexander Nicol, Wei Qin, Ryan T K Kwok, Jeffrey Mark Burkhartsmeyer, Zhenfeng Zhu, Huifang Su, Wenwen Luo, Jacky W Y Lam, Jun Qian, Kam Sing Wong, Ben Zhong Tang
Multiphoton microscopy is an exciting tool for biomedical research because it can be used to image single cells in vivo due to its greater penetration depth, lower phototoxicity and higher resolution when compared to confocal laser scanning microscopy. This helps researchers understand how certain cells change over time and evaluate the efficacy of different therapies. Herein, we report a new AIE luminogen (AIEgen), abbreviated as TPE-TETRAD, with a favorable absorption and efficient deep-red emission in the solid state...
June 1, 2017: Chemical Science
Manuela Lahne, David R Hyde
Sensing and responding to our environment requires functional neurons that act in concert. Neuronal cell loss resulting from degenerative diseases cannot be replaced in humans, causing a functional impairment to integrate and/or respond to sensory cues. In contrast, zebrafish (Danio rerio) possess an endogenous capacity to regenerate lost neurons. Here, we will focus on the processes that lead to neuronal regeneration in the zebrafish retina. Dying retinal neurons release a damage signal, tumor necrosis factor α, which induces the resident radial glia, the Müller glia, to reprogram and re-enter the cell cycle...
August 2017: Neural Regeneration Research
Jack Hornsby, Donna M Daly, David Grundy, Fangzhou Cheng, Anne M Robertson, Paul N Watton, Mark S Thompson
Urodynamic tests are the gold standard for the diagnosis of bladder dysfunction, and the mechanical compliance of the bladder is an important parameter in these tests. The bladder wall has a layered structure, differentially affected by pathology, so knowledge of the contribution and role of these layers and their constituents to overall bladder compliance will enhance interpretation of these clinical tests. In this study we document the functional morphology of the detrusor and lamina propria of the murine bladder wall using a custom in-situ tensile loading system under multiphoton microscopy (MPM) observation in unloaded state and under incremental uniaxial stretch...
December 2017: Acta Biomaterialia
Lauren S Richardson, Gracie Vargas, Tyra Brown, Lorenzo Ochoa, Samantha Sheller-Miller, George R Saade, Robert N Taylor, Ramkumar Menon
This study obtained visual evidence of novel cellular and extracellular matrix-level structural alterations in term and preterm human fetal amniochorionic membranes. Amniochorions were collected from term cesarean (not in labor) or vaginal (labor) deliveries, preterm premature rupture of membranes, and spontaneous preterm birth. To determine the effect of oxidative stress on membranes at term or preterm labor, term not in labor samples in an organ explant culture in vitro were exposed to cigarette smoke extract...
September 20, 2017: American Journal of Pathology
Meng Li, Haobo Ge, Vincenzo Mirabello, Rory L Arrowsmith, Gabriele Kociok-Köhn, Stanley W Botchway, Weihong Zhu, Sofia I Pascu, Tony D James
A naphthalimide-based chemosensing motif turns ON the fluorescence emission in solution in the presence of aqueous iron(iii) chloride, and maintains this property in living cancer cells. The emission response to Fe(iii) ions occurs simultaneously with a change in pH. The protonation of methyl piperazine-conjugated naphthalimide promotes its lysosomal localisation as assessed by co-localisation tests and fluorescence lifetime imaging microscopy (FLIM) in vitro.
October 18, 2017: Chemical Communications: Chem Comm
Mamunur Rashid, Judson Belmont, David Carpenter, Christopher E Turner, Eric C Olson
Paxillin and Hic-5 are homologous focal adhesion adaptor proteins that coordinate cytoskeletal rearrangements in response to integrin-signaling, but their role(s) in cortical development are unknown. Here, we find that Hic-5 deficient mice are postnatal viable with normal cortical layering. Mice with a neural-specific deletion of paxillin are also postnatal viable, but show evidence of a cortical neuron migration delay that is evident pre and perinatally, but is not detected at postnatal day 35 (P35). This phenotype is not modified by Hic-5 deficiency (double knockout)...
September 21, 2017: Development
Jian Li, Holger Jahr, Wei Zheng, Pei-Gen Ren
The reconstruction of critically sized bone defects remains a serious clinical problem because of poor angiogenesis within tissue-engineered scaffolds during repair, which gives rise to a lack of sufficient blood supply and causes necrosis of the new tissues. Rapid vascularization is a vital prerequisite for new tissue survival and integration with existing host tissue. The de novo generation of vasculature in scaffolds is one of the most important steps in making bone regeneration more efficient, allowing repairing tissue to grow into a scaffold...
September 7, 2017: Journal of Visualized Experiments: JoVE
Chandika Amarasinghe, Alexander Kamasah, Casey D Foley, James O F Thompson, Arthur G Suits
We present the findings of the first imaging study of trans-HONO and cis-HONO photodissociation through the [Formula: see text] band and [Formula: see text] band of the Ã(1)A″-X̃(1)A' transition. The NO photofragment was probed by (1 + 1) resonance-enhanced multiphoton ionization and studied using the direct-current slice imaging technique with our finite slice reconstruction method. The NO state-specific translational energy distributions show some rotational structure corresponding to the internal state distribution in the OH cofragment...
October 3, 2017: Journal of Physical Chemistry. A
Pierre Mahou, Guy Malkinson, Élodie Chaudan, Thierry Gacoin, Emmanuel Beaurepaire, Willy Supatto
In multiphoton microscopy, the ongoing trend toward the use of excitation wavelengths spanning the entire near-infrared range calls for new standards in order to quantify and compare the performances of microscopes. This article describes a new method for characterizing the imaging properties of multiphoton microscopes over a broad range of excitation wavelengths in a straightforward and efficient manner. It demonstrates how second harmonic generation (SHG) nanoprobes can be used to map the spatial resolution, field curvature, and chromatic aberrations across the microscope field of view with a precision below the diffraction limit and with unique advantages over methods based on fluorescence...
September 19, 2017: Small
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