Selected Grantee Publications
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- 15 results found
- R41/R42 [STTR]
- R43/R44 [SBIR]
Spatiotemporal Image Reconstruction to Enable High-Frame-Rate Dynamic Photoacoustic Tomography With Rotating-Gantry Volumetric Imagers
Cam et al., Journal of Biomedical Optics . 2024.
https://pubmed.ncbi.nlm.nih.gov/38249994
Dynamic photoacoustic computed tomography (PACT) is a valuable imaging technique for monitoring physiological processes. However, the current imaging techniques are often limited to two-dimensional spatial imaging. While PACT imagers capable of taking three-dimensional spatial images are commercially available, these systems have substantial limitations. Typically, the data are acquired sequentially rather than simultaneously at all views. The objects being imaged are dynamic and can vary during this process; as such, image reconstruction is inherently difficult, and the result is often incomplete. Cam et al. propose an image reconstruction method that can address these challenges and enable volumetric dynamic PACT imaging using existing preclinical imagers, which has the potential to significantly advance preclinical research and facilitate the monitoring of critical physiological biomarkers. Supported by ORIP (R44OD023029) and NIBIB.
The Effect of Common Paralytic Agents Used for Fluorescence Imaging on Redox Tone and ATP Levels in Caenorhabditis elegans
Morton et al., PLOS One. 2024.
https://pubmed.ncbi.nlm.nih.gov/38669260
Caenorhabditis elegans is a highly valuable model organism in biological research. However, these worms must be paralyzed for most imaging applications, and the effect that common chemical anesthetics may have on the parameters measured—especially biochemical measurements such as cellular energetics and redox tone—is poorly understood. In this study, the authors used two reporters—QUEEN-2m for relative ATP levels and reduction-oxidation–sensitive green fluorescent protein for redox tone—to assess the impact of commonly used chemical paralytics. The results show that all chemical anesthetics at doses required for full paralysis alter redox tone and/or ATP levels, and anesthetic use alters the detected outcome of rotenone exposure on relative ATP levels and redox tone. Therefore, it is important to tailor the use of anesthetics to different endpoints and experimental questions and to develop less disruptive paralytic methods for optimal imaging of dynamic in vivo reporters. Supported by ORIP (P40OD010440, R44OD024963) and NIEHS.
Characterizing a Photoacoustic and Fluorescence Imaging Platform for Preclinical Murine Longitudinal Studies
Thompson et al., Journal of Biomedical Optics . 2023.
https://pubmed.ncbi.nlm.nih.gov/36895414/
Preclinical studies using animal models require medical imaging technology with sufficient resolution and sensitivity for anatomical, functional, and molecular assessments. Photoacoustic (PA) tomography provides high resolution and specificity, and fluorescence (FL) molecular tomography provides high sensitivity; the combination of these imaging modalities capitalizes on their strengths and mitigates disadvantages. In this publication, the authors describe TriTom, a preclinical imaging system that integrates PA and FL. They characterized the PA spatial resolution, PA sensitivity, PA spectral accuracy, optical spatial resolution, and FL sensitivity of the platform and demonstrated anatomical imaging in mice. This report demonstrates TriTom’s suitability for biomedical imaging applications. Supported by ORIP (R43OD023029) and NCI.
Gigapixel Imaging With a Novel Multi-Camera Array Microscope
Thomson et al., eLife. 2022.
https://www.doi.org/10.7554/eLife.74988
The dynamics of living organisms are organized across many spatial scales. The investigators created assembled a scalable multi-camera array microscope (MCAM) that enables comprehensive high-resolution, large field-of-view recording from multiple spatial scales simultaneously, ranging from structures that approach the cellular scale to large-group behavioral dynamics. By collecting data from up to 96 cameras, they computationally generated gigapixel-scale images and movies with a field of view over hundreds of square centimeters at an optical resolution of 18 µm. This system allows the team to observe the behavior and fine anatomical features of numerous freely moving model organisms on multiple spatial scales (e.g., larval zebrafish, fruit flies, slime mold). Overall, by removing the bottlenecks imposed by single-camera image acquisition systems, the MCAM provides a powerful platform for investigating detailed biological features and behavioral processes of small model organisms. Supported by ORIP (R44OD024879), NIEHS, NCI, and NIBIB.
Sunitinib Inhibits STAT3 Phosphorylation in Cardiac Muscle and Prevents Cardiomyopathy in the mdx Mouse Model of Duchenne Muscular Dystrophy
Oliveira-Santos et al., Human Molecular Genetics. 2022.
https://www.doi.org/10.1093/hmg/ddac042
Duchenne muscular dystrophy (DMD) is the most common form of muscular dystrophy, affecting about 1 in 5,000 boys worldwide. DMD is a fatal X-linked genetic disorder that results from mutations in the dystrophin gene and leads to progressive muscular degeneration. Individuals with DMD often die at a young age from respiratory or heart failure. To date, few studies have examined the basis of cardiac failure associated with DMD, and no effective U.S. Food and Drug Administration (FDA)–approved treatment options are available. Using a mouse model of both sexes, researchers characterized the effectiveness of sunitinib, an FDA-approved small-molecule drug, in preventing DMD-related cardiomyopathy. The treatment reduced STAT3 activation in cardiac muscle and prevented cardiomyopathy disease progression. Inhibition of STAT3 activation in cardiac muscle can reduce inflammation and fibrosis and prevent heart failure. These findings demonstrate sunitinib’s potential as a novel treatment option for skeletal and cardiac muscle dysfunction in patients with DMD. Supported by ORIP (R42OD030543).
A Novel Wireless ECG System for Prolonged Monitoring of Multiple Zebrafish for Heart Disease and Drug Screening Studies
Le et al., Biosensors and Bioelectronics. 2022.
https://pubmed.ncbi.nlm.nih.gov/34801796/
Zebrafish and their mutant lines have been extensively used in cardiovascular studies. In the current study, the novel system Zebra II is presented for prolonged electrocardiogram (ECG) acquisition and analysis for multiple zebrafish within controllable working environments. The Zebra II is composed of a perfusion system, apparatuses, sensors, and an in-house electronic system. First, the Zebra II is validated in comparison with a benchmark system, namely iWORX, through various experiments. The validation displayed comparable results in terms of data quality and ECG changes in response to drug treatment. The effects of anesthetic drugs and temperature variation on zebrafish ECG were subsequently investigated in experiments that need real-time data assessment. The Zebra II's capability of continuous anesthetic administration enabled prolonged ECG acquisition up to 1 h compared to that of 5 min in existing systems. The novel cloud-based automated analysis with data obtained from four fish further provided a useful solution for combinatorial experiments and helped save significant time and effort. The system showed robust ECG acquisition and analytics for various applications, including arrhythmia in sodium-induced sinus arrest, temperature-induced heart rate variation, and drug-induced arrhythmia in Tg(SCN5A-D1275N) mutant and wildtype fish. The multiple channel acquisition also enabled the implementation of randomized controlled trials on zebrafish models. The developed ECG system holds promise and solves current drawbacks in order to greatly accelerate drug screening applications and other cardiovascular studies using zebrafish. Supported by ORIP (R44OD024874) and NHLBI.
Functional and Ultrastructural Analysis of Reafferent Mechanosensation in Larval Zebrafish
Odstrcil et al., Current Biology. 2022.
https://www.sciencedirect.com/science/article/pii/S096098222101530X
All animals need to differentiate between exafferent stimuli (caused by the environment) and reafferent stimuli (caused by their own movement). Researchers characterized how hair cells in zebrafish larvae discriminate between reafferent and exafferent signals. Dye labeling of the lateral line nerve and functional imaging was combined with ultra-structural electron microscopy circuit reconstruction to show that cholinergic signals originating from the hindbrain transmit efference copies, and dopaminergic signals from the hypothalamus may affect threshold modulation. Findings suggest that this circuit is the core implementation of mechanosensory reafferent suppression in these young animals. Supported by ORIP (R43OD024879, R44OD024879) and NINDS.
Precise Visuomotor Transformations Underlying Collective Behavior in Larval Zebrafish
Harpaz et al., Nature Communications. 2021.
https://www.nature.com/articles/s41467-021-26748-0
Sensory signals from neighbors, analyzed in the visuomotor stream of animals, is poorly understood. The authors studied aggregation behavior in larval zebrafish and found that over development larvae transition from over dispersed groups to tight shoals. Young larvae turn away from virtual neighbors by integrating and averaging retina-wide visual occupancy within each eye, and by using a winner-take-all strategy for binocular integration. Observed algorithms accurately predict group structure over development. These findings allow testable predictions regarding the neuronal circuits underlying collective behavior in zebrafish. Supported by ORIP (R43OD024879, R44OD024879) and NINDS.
Collective Behavior Emerges from Genetically Controlled Simple Behavioral Motifs in Zebrafish
Harpaz et al., Science Advances. 2021.
https://www.science.org/doi/10.1126/sciadv.abi7460
Harpaz et al. report that zebrafish regulate their proximity and alignment with each other at early larval stages. Two visual responses (one measuring relative visual field occupancy and one accounting for global visual motion), account for emerging group behavior. Mutations in genes known to affect social behavior in humans perturb these reflexes in individual larval zebrafish and change their emergent collective behaviors. Model simulations show that changes in these two responses in individual mutant animals predict well the distinctive collective patterns that emerge in a group. Hence, group behaviors reflect in part genetically defined primitive sensorimotor “motifs” evident in young larvae. Supported by ORIP (R43OD024879, R44OD024879) and NINDS.
Deep Learning-Based Framework for Cardiac Function Assessment in Embryonic Zebrafish from Heart Beating Videos
Naderi et al., Computers in Biology and Medicine. 2021.
https://www.sciencedirect.com/science/article/pii/S0010482521003590
Zebrafish is a powerful model system for a host of biological investigations, cardiovascular studies, and genetic screening. However, the current methods for quantifying and monitoring zebrafish cardiac functions involve tedious manual work and inconsistent estimations. Naderi et al. developed a Zebrafish Automatic Cardiovascular Assessment Framework (ZACAF) based on a U-net deep learning model for automated assessment of cardiovascular indices, such as ejection fraction (EF) and fractional shortening (FS) from microscopic videos of wildtype and cardiomyopathy mutant zebrafish embryos. The framework could be widely applicable with any laboratory resources, and the automatic feature holds promise to enable efficient, consistent, and reliable processing and analysis capacity. Supported by ORIP (R44OD024874)