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Salmon AE, Chen RCH, Atry F, Gaffney M, Merriman DK, Gil DA, Skala MC, Collery R, Allen KP, Buckland E, Pashaie R, Carroll J. Optical Coherence Tomography Angiography in the Thirteen-Lined Ground Squirrel. Transl Vis Sci Technol 2021; 10:5. [PMID: 34232271 PMCID: PMC8267221 DOI: 10.1167/tvst.10.8.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To assess the performance of two spectral-domain optical coherence tomography-angiography systems in a natural model of hypoperfusion: the hibernating thirteen-lined ground squirrel (13-LGS). Methods Using a high-speed (130 kHz) OCT-A system (HS-OCT-A) and a commercial OCT (36 kHz; Bioptigen Envisu; BE-OCT-A), we imaged the 13-LGS retina throughout its hibernation cycle. Custom software was used to extract the superior, middle, and deep capillary plexus (SCP, MCP, and DCP, respectively). The retinal vasculature was also imaged with adaptive optics scanning light ophthalmoscopy (AOSLO) during torpor to visualize individual blood cells. Finally, correlative histology with immunolabeled or DiI-stained vasculature was performed. Results During euthermia, vessel density was similar between devices for the SCP and MCP (P = 0.88, 0.72, respectively), with a small difference in the DCP (−1.63 ± 1.54%, P = 0.036). Apparent capillary dropout was observed during torpor, but recovered after forced arousal, and this effect was exaggerated in high-speed OCT-A imaging. Based on cell flux measurements with AOSLO, increasing OCT-A scan duration by ∼1000× would avoid the apparent capillary dropout artifact. High correspondence between OCT-A (during euthermia) and histology enabled lateral scale calibration. Conclusions While the HS-OCT-A system provides a more efficient workflow, the shorter interscan interval may render it more susceptible to the apparent capillary dropout artifact. Disambiguation between capillary dropout and transient ischemia can have important implications in the management of retinal disease and warrants additional diagnostics. Translational Relevance The 13-LGS provides a natural model of hypoperfusion that may prove valuable in modeling the utility of OCT-A in human pathologies associated with altered blood flow.
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Affiliation(s)
- Alexander E Salmon
- Cell Biology, Neurobiology, & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA.,Translational Imaging Innovations, Hickory, NC, USA
| | - Rex Chin-Hao Chen
- Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | - Farid Atry
- Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | - Mina Gaffney
- Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
| | | | - Daniel A Gil
- Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, USA.,Morgridge Institute for Research, Madison, WI, USA
| | - Melissa C Skala
- Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, USA.,Morgridge Institute for Research, Madison, WI, USA
| | - Ross Collery
- Cell Biology, Neurobiology, & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA.,Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Kenneth P Allen
- Microbiology & Immunology, Medical College of Wisconsin, Milwaukee, WI, USA
| | | | - Ramin Pashaie
- Computer & Electrical Engineering, Florida Atlantic University, Boca Raton, FL, USA
| | - Joseph Carroll
- Cell Biology, Neurobiology, & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA.,Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA.,Biomedical Engineering, Marquette University, Milwaukee WI, USA
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Chin-Hao Chen R, Atry F, Richner T, Brodnick S, Pisaniello J, Ness J, Suminski AJ, Williams J, Pashaie R. A system identification analysis of optogenetically evoked electrocorticography and cerebral blood flow responses. J Neural Eng 2020; 17:056049. [PMID: 32299067 DOI: 10.1088/1741-2552/ab89fc] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE The main objective of this research was to study the coupling between neural circuits and the vascular network in the cortex of small rodents from system engineering point of view and generate a mathematical model for the dynamics of neurovascular coupling. The model was adopted to implement closed-loop blood flow control algorithms. APPROACH We used a combination of advanced technologies including optogenetics, electrocorticography, and optical coherence tomography to stimulate selected populations of neurons and simultaneously record induced electrocorticography and hemodynamic signals. We adopted system identification methods to analyze the acquired data and investigate the relation between optogenetic neural activation and consequential electrophysiology and blood flow responses. MAIN RESULTS We showed that the developed model, once trained by the acquired data, could successfully regenerate subtle spatio-temporal features of evoked electrocorticography and cerebral blood flow responses following an onset of optogenetic stimulation. SIGNIFICANCE The long term goal of this research is to open a new line for computational analysis of neurovascular coupling particularly in pathologies where the normal process of blood flow regulation in the central nervous system is disrupted including Alzheimer's disease.
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Affiliation(s)
- Rex Chin-Hao Chen
- Electrical Engineering, Computer Science Department, University of Wisconsin-Milwaukee, 3200N Cramer St., Milwaukee, WI, United States of America
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Atry F, Rentchler E, Alkmin S, Dai B, Li B, Eliceiri KW, Campagnola PJ. Parallel multiphoton excited fabrication of tissue engineering scaffolds using a diffractive optical element. OPTICS EXPRESS 2020; 28:2744-2757. [PMID: 32121956 PMCID: PMC7053494 DOI: 10.1364/oe.381362] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 12/21/2019] [Accepted: 12/25/2019] [Indexed: 05/08/2023]
Abstract
Multiphoton excited photochemistry is a powerful technique for freeform nano/microfabrication. However, the construction of large and complex structures using single point scanning is slow, where this is a significant limitation for biological investigations. We demonstrate increased throughput via parallel fabrication using a diffractive optical element. To implement an approach with large field of view and near-theoretical resolution, a scan lens was designed that is optimized for using low-magnification high NA objective lenses. We demonstrate that with this approach it is possible to synthesize large scaffolds at speeds several times faster than by single point scanning.
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Affiliation(s)
- Farid Atry
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Eric Rentchler
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Samuel Alkmin
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Bing Dai
- Laboratory for Optical and Computational Instrumentation, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Bin Li
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA
- Laboratory for Optical and Computational Instrumentation, University of Wisconsin-Madison, Madison, WI 53706, USA
- Morgridge Institute for Research, Madison, WI 53706, USA
| | - Kevin W. Eliceiri
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA
- Laboratory for Optical and Computational Instrumentation, University of Wisconsin-Madison, Madison, WI 53706, USA
- Morgridge Institute for Research, Madison, WI 53706, USA
- Medical Physics Department, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Paul J. Campagnola
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA
- Laboratory for Optical and Computational Instrumentation, University of Wisconsin-Madison, Madison, WI 53706, USA
- Medical Physics Department, University of Wisconsin-Madison, Madison, WI 53706, USA
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Azimipour M, Sheikhzadeh M, Baumgartner R, Cullen PK, Helmstetter FJ, Chang WJ, Pashaie R. Fluorescence laminar optical tomography for brain imaging: system implementation and performance evaluation. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:16003. [PMID: 28056143 PMCID: PMC5997009 DOI: 10.1117/1.jbo.22.1.016003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 12/12/2016] [Indexed: 05/04/2023]
Abstract
We present our effort in implementing a fluorescence laminar optical tomography scanner which is specifically designed for noninvasive three-dimensional imaging of fluorescence proteins in the brains of small rodents. A laser beam, after passing through a cylindrical lens, scans the brain tissue from the surface while the emission signal is captured by the epi-fluorescence optics and is recorded using an electron multiplication CCD sensor. Image reconstruction algorithms are developed based on Monte Carlo simulation to model light–tissue interaction and generate the sensitivity matrices. To solve the inverse problem, we used the iterative simultaneous algebraic reconstruction technique. The performance of the developed system was evaluated by imaging microfabricated silicon microchannels embedded inside a substrate with optical properties close to the brain as a tissue phantom and ultimately by scanning brain tissue in vivo. Details of the hardware design and reconstruction algorithms are discussed and several experimental results are presented. The developed system can specifically facilitate neuroscience experiments where fluorescence imaging and molecular genetic methods are used to study the dynamics of the brain circuitries.
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Affiliation(s)
- Mehdi Azimipour
- University of Wisconsin–Milwaukee, Electrical and Computer Engineering Department, 3200 North Cramer Street, Milwaukee, Wisconsin 53211, United States
| | - Mahya Sheikhzadeh
- University of Wisconsin–Milwaukee, Electrical and Computer Engineering Department, 3200 North Cramer Street, Milwaukee, Wisconsin 53211, United States
| | - Ryan Baumgartner
- University of Wisconsin–Milwaukee, Electrical and Computer Engineering Department, 3200 North Cramer Street, Milwaukee, Wisconsin 53211, United States
| | - Patrick K. Cullen
- University of Wisconsin–Milwaukee, Psychology Department, 2441 East Hartford Avenue, 207 Garland Hall, Milwaukee, Wisconsin 53211, United States
| | - Fred J. Helmstetter
- University of Wisconsin–Milwaukee, Psychology Department, 2441 East Hartford Avenue, 207 Garland Hall, Milwaukee, Wisconsin 53211, United States
| | - Woo-Jin Chang
- University of Wisconsin–Milwaukee, Mechanical Engineering Department, 3200 North Cramer Street, Milwaukee, Wisconsin 53211, United States
| | - Ramin Pashaie
- University of Wisconsin–Milwaukee, Electrical and Computer Engineering Department, 3200 North Cramer Street, Milwaukee, Wisconsin 53211, United States
- Address all correspondence to: Ramin Pashaie, E-mail:
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