scholarly journals A 16-channel loop array for in vivo macaque whole-brain imaging at 3 T

2020 ◽  
Vol 68 ◽  
pp. 167-172 ◽  
Author(s):  
Zhiyan Quan ◽  
Yang Gao ◽  
Shuxian Qu ◽  
Xiaojie Wang ◽  
Robert M. Friedman ◽  
...  
Keyword(s):  
2012 ◽  
Vol 107 (10) ◽  
pp. 2853-2865 ◽  
Author(s):  
Ji-Wei He ◽  
Fenghua Tian ◽  
Hanli Liu ◽  
Yuan Bo Peng

While near-infrared (NIR) spectroscopy has been increasingly used to detect stimulated brain activities with an advantage of dissociating regional oxy- and deoxyhemoglobin concentrations simultaneously, it has not been utilized much in pain research. Here, we investigated and demonstrated the feasibility of using this technique to obtain whole brain hemodynamics in rats and speculated on the functional relevance of the NIR-based hemodynamic signals during pain processing. NIR signals were emitted and collected using a 26-optodes array on rat's dorsal skull surface after the removal of skin. Following the subcutaneous injection of formalin (50 μl, 3%) into a hindpaw, several isolable brain regions showed hemodynamic changes, including the anterior cingulate cortex, primary/secondary somatosensory cortexes, thalamus, and periaqueductal gray ( n = 6). Time courses of hemodynamic changes in respective regions matched with the well-documented biphasic excitatory response. Surprisingly, an atypical pattern (i.e., a decrease in oxyhemoglobin concentration with a concomitant increase in deoxyhemoglobin concentration) was seen in phase II. In a separate group of rats with innocuous brush and noxious pinch of the same area ( n = 11), results confirmed that the atypical pattern occurred more likely in the presence of nociception than nonpainful stimulation, suggesting it as a physiological substrate when the brain processes pain. In conclusion, the NIR whole brain imaging provides a useful alternative to study pain in vivo using small-animal models. Our results support the notion that neurovascular response patterns depend on stimuli, bringing attention to the interpretation of vascular-based neuroimaging data in studies of pain.


2015 ◽  
Vol 6 (5) ◽  
pp. 1797 ◽  
Author(s):  
Zhe Yang ◽  
Li Mei ◽  
Fei Xia ◽  
Qingming Luo ◽  
Ling Fu ◽  
...  

2018 ◽  
Author(s):  
Jennifer D. Whitesell ◽  
Alex R. Buckley ◽  
Joseph E. Knox ◽  
Leonard Kuan ◽  
Nile Graddis ◽  
...  

AbstractA variety of Alzheimer’s disease (AD) mouse models overexpress mutant forms of human amyloid precursor protein (APP), producing high levels of amyloid β (Aβ) and forming plaques However, the degree to which these models mimic spatiotemporal patterns of Aβ deposition in brains of AD patients is unknown. Here, we mapped the spatial distribution of Aβ plaques across ages in three APP-overexpression mouse lines (APP/PS1, Tg2576, hAPP-J20) using in vivo labeling with methoxy-X04, high throughput whole brain imaging, and an automated informatics pipeline. Images were acquired with high resolution serial 2-photon tomography and labeled plaques were detected using custom-built segmentation algorithms. Image series were registered to the Allen Mouse Brain Common Coordinate Framework, a 3D reference atlas, enabling automated brain-wide quantification of plaque density, number, and location. In both APP/PS1 and Tg2576 mice, plaques were identified first in isocortex, followed by olfactory, hippocampal, and cortical subplate areas. In hAPP-J20 mice, plaque density was highest in hippocampal areas, followed by isocortex, with little to no involvement of olfactory or cortical subplate areas. Within the major brain divisions, distinct regions were identified with high (or low) plaque accumulation; e.g., the lateral visual area within the isocortex of APP/PS1 mice had relatively higher plaque density compared with other cortical areas, while in hAPP-J20 mice, plaques were densest in the ventral retrosplenial cortex. In summary, we show how whole brain imaging of amyloid pathology in mice reveals the extent to which a given model recapitulates the regional Aβ deposition patterns described in AD.


2020 ◽  
Author(s):  
Jing Yang ◽  
Wei Yin ◽  
Richard Van ◽  
Keyi Yin ◽  
Peng Wang ◽  
...  

<div>Fluorescence and chemiluminescence imaging are the most widely applied optical emissive imaging</div><div>methods in biomedical research. “Smart” (turn-on) fluorescence imaging has been routinely used for in</div><div>vitro, cellular, and in vivo imaging; however, smart chemiluminescence imaging has been rarely explored.</div><div>In this report, we designed chemiluminescence probe ADLumin-1 and validated that ADLumin-1 was a</div><div>smart chemiluminescence probe for amyloid beta (Ab) species, evidenced by a 216-fold amplification of</div><div>chemiluminescence intensity upon mixing with Abs in vitro. In vivo two photon imaging indicated that</div><div>ADLumin-1 could efficiently cross blood-brain- barrier (BBB) and provided excellent contrast both for Ab</div><div>plaques and cerebral amyloid angiopathy (CAA). In vivo whole brain imaging showed that the</div><div>chemiluminescence signal of ADLumin-1 from 5-month-old transgenic AD (5xFAD) mice was 1.80-fold</div><div>higher than that from the age-matched wild-type mice. Moreover, we demonstrated that it was feasible to</div><div>further dually-amplify signal via chemiluminescence resonance energy transfer (DAS-CRET) using two</div><div>non-conjugated smart probes (ADLumin-1 and CRANAD-3) in solutions, brain homogenates, and in vivo</div><div>whole brain imaging. Our results showed that DAS-CRET could provide a 2.25-fold margin between 5-</div><div>month-old 5xFAD mice and wild type mice. To our knowledge, this is the first report that a</div><div>chemiluminescence probe could be used for detecting Ab species both in vitro and in vivo. Although</div><div>ADLumin-1 was designed for Abs, we believe that our strategy could be potentially extended to a wide</div><div>range of targets, including other aggregating-prone proteins. Notably, our results suggested that the</div><div>strategies for turning-on fluorescence could be used for amplifying chemiluminescence, and we believe that</div><div>our studies could inspire considerably more research on chemiluminescence imaging</div>


2021 ◽  
Author(s):  
Alina Scholz ◽  
Robin Etzel ◽  
Markus W May ◽  
Mirsad Mahmutovic ◽  
Qiyuan Tian ◽  
...  

AbstractIn vivo diffusion-weighted magnetic resonance imaging is limited in signal-to-noise-ratio (SNR) and acquisition time, which constrains spatial resolution to the macroscale regime. Ex vivo imaging, which allows for arbitrarily long scan times, is critical for exploring human brain structure in the mesoscale regime without loss of SNR. Standard head array coils designed for patients are sub-optimal for imaging ex vivo whole brain specimens. The goal of this work was to design and construct a 48-channel ex vivo whole brain array coil for high-resolution and high b-value diffusion-weighted imaging on a 3T Connectome scanner. The coil was validated with bench measurements and characterized by imaging metrics on an agar brain phantom and an ex vivo human brain sample. The two-segment coil former was constructed for a close fit to a whole human brain, with small receive elements distributed over the entire brain. Imaging tests including SNR and G-factor maps were compared to a 64-channel head coil designed for in vivo use. There was a 2.9-fold increase in SNR in the peripheral cortex and a 1.3-fold gain in the center when compared to the 64-ch head coil. The 48-channel ex vivo whole brain coil also decreases noise amplification in highly parallel imaging, allowing acceleration factors of approximately one unit higher for a given noise amplification level. The acquired diffusion-weighted images in a whole ex vivo brain specimen demonstrate the applicability of the developed coil for high-resolution and high b-value diffusion-weighted ex vivo brain MRI studies.


2020 ◽  
Author(s):  
Jing Yang ◽  
Wei Yin ◽  
Richard Van ◽  
Keyi Yin ◽  
Peng Wang ◽  
...  

<div>Fluorescence and chemiluminescence imaging are the most widely applied optical emissive imaging</div><div>methods in biomedical research. “Smart” (turn-on) fluorescence imaging has been routinely used for in</div><div>vitro, cellular, and in vivo imaging; however, smart chemiluminescence imaging has been rarely explored.</div><div>In this report, we designed chemiluminescence probe ADLumin-1 and validated that ADLumin-1 was a</div><div>smart chemiluminescence probe for amyloid beta (Ab) species, evidenced by a 216-fold amplification of</div><div>chemiluminescence intensity upon mixing with Abs in vitro. In vivo two photon imaging indicated that</div><div>ADLumin-1 could efficiently cross blood-brain- barrier (BBB) and provided excellent contrast both for Ab</div><div>plaques and cerebral amyloid angiopathy (CAA). In vivo whole brain imaging showed that the</div><div>chemiluminescence signal of ADLumin-1 from 5-month-old transgenic AD (5xFAD) mice was 1.80-fold</div><div>higher than that from the age-matched wild-type mice. Moreover, we demonstrated that it was feasible to</div><div>further dually-amplify signal via chemiluminescence resonance energy transfer (DAS-CRET) using two</div><div>non-conjugated smart probes (ADLumin-1 and CRANAD-3) in solutions, brain homogenates, and in vivo</div><div>whole brain imaging. Our results showed that DAS-CRET could provide a 2.25-fold margin between 5-</div><div>month-old 5xFAD mice and wild type mice. To our knowledge, this is the first report that a</div><div>chemiluminescence probe could be used for detecting Ab species both in vitro and in vivo. Although</div><div>ADLumin-1 was designed for Abs, we believe that our strategy could be potentially extended to a wide</div><div>range of targets, including other aggregating-prone proteins. Notably, our results suggested that the</div><div>strategies for turning-on fluorescence could be used for amplifying chemiluminescence, and we believe that</div><div>our studies could inspire considerably more research on chemiluminescence imaging</div>


Cell Reports ◽  
2021 ◽  
Vol 34 (5) ◽  
pp. 108709
Author(s):  
Xiaojun Wang ◽  
Hanqing Xiong ◽  
Yurong Liu ◽  
Tao Yang ◽  
Anan Li ◽  
...  

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
M. H. Sanad ◽  
A. B. Farag ◽  
S. F. A. Rizvi

Abstract This study presents development and characterization of a radiotracer, [125I]iodonefiracetam ([125I]iodoNEF). Labeling with high yield and radiochemical purity was achieved through the formation of a [125I]iodoNEF radiotracer after investigating many factors like oxidizing agent content (chloramines-T (Ch-T)), substrate amount (Nefiracetam (NEF)), pH of reaction mixture, reaction time and temperature. Nefiracetam (NEF) is known as nootropic agent, acting as N-methyl-d-aspartic acid receptor ligand (NMDA). The radiolabeled compound was stable, and exhibited the logarithm of the partition coefficient (log p) value of [125I]iodonefiracetam as 1.85 (lipophilic). Biodistribution studies in normal mice confirmed the suitability of the [125I]iodoNEF radiotracer as a novel tracer for brain imaging. High uptake of 8.61 ± 0.14 percent injected dose/g organ was observed in mice


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