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Tsytsarev V, Sopova JV, Leonova EI, Inyushin M, Markina AA, Chirinskaite AV, Volnova AB. Neurophotonic methods in approach to in vivo animal epileptic models: Advantages and limitations. Epilepsia 2024; 65:600-614. [PMID: 38115808 PMCID: PMC10948300 DOI: 10.1111/epi.17870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 12/16/2023] [Accepted: 12/18/2023] [Indexed: 12/21/2023]
Abstract
Neurophotonic technology is a rapidly growing group of techniques that are based on the interactions of light with natural or genetically modified cells of the neural system. New optical technologies make it possible to considerably extend the tools of neurophysiological research, from the visualization of functional activity changes to control of brain tissue excitability. This opens new perspectives for studying the mechanisms underlying the development of human neurological diseases. Epilepsy is one of the most common brain disorders; it is characterized by recurrent seizures and affects >1% of the world's population. However, how seizures occur, spread, and terminate in a healthy brain is still unclear. Therefore, it is extremely important to develop appropriate models to accurately explore the causal relationship of epileptic activity. The use of neurophotonic technologies in epilepsy research falls into two broad categories: the visualization of neural epileptic activity, and the direct optical influence on neurons to induce or suppress epileptic activity. An optogenetic variant of the classical kindling model of epileptic seizures, in which activatable cells are genetically defined, is called optokindling. Research is also underway concerning the application of neurophotonic techniques for suppressing epileptic activity, aiming to bring these methods into clinical practice. This review aims to systematize and describe new approaches that use combinations of different neurophotonic methods to work with in vivo models of epilepsy. These approaches overcome many of the shortcomings associated with classical animal models of epilepsy and thus increase the effectiveness of developing new diagnostic methods and antiepileptic therapy.
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Affiliation(s)
- Vassiliy Tsytsarev
- University of Maryland School of Medicine, Department of Neurobiology 20 Penn St, HSF-2, 21201 MD, Baltimore, United States
| | - Julia V. Sopova
- Center of Transgenesis and Genome Editing, St. Petersburg State University, 199034 St. Petersburg, Russia
| | - Elena I. Leonova
- Center of Transgenesis and Genome Editing, St. Petersburg State University, 199034 St. Petersburg, Russia
| | - Mikhail Inyushin
- School of Medicine, Universidad Central del Caribe, Bayamon, PR 00956, USA
| | - Alisa A. Markina
- Institute of Translational Biomedicine, Saint Petersburg State University, St. Petersburg 199034, Russia
| | - Angelina V. Chirinskaite
- Center of Transgenesis and Genome Editing, St. Petersburg State University, 199034 St. Petersburg, Russia
| | - Anna B. Volnova
- Institute of Translational Biomedicine, Saint Petersburg State University, St. Petersburg 199034, Russia
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Tang Q, Tsytsarev V, Yan F, Wang C, Erzurumlu RS, Chen Y. In vivo voltage-sensitive dye imaging of mouse cortical activity with mesoscopic optical tomography. NEUROPHOTONICS 2020; 7:041402. [PMID: 33274250 PMCID: PMC7708784 DOI: 10.1117/1.nph.7.4.041402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Accepted: 11/11/2020] [Indexed: 05/11/2023]
Abstract
Significance: Cellular layering is a hallmark of the mammalian neocortex with layer and cell type-specific connections within the cortical mantle and subcortical connections. A key challenge in studying circuit function within the neocortex is to understand the spatial and temporal patterns of information flow between different columns and layers. Aim: We aimed to investigate the three-dimensional (3D) layer- and area-specific interactions in mouse cortex in vivo. Approach: We applied a new promising neuroimaging method-fluorescence laminar optical tomography in combination with voltage-sensitive dye imaging (VSDi). VSDi is a powerful technique for interrogating membrane potential dynamics in assemblies of cortical neurons, but it is traditionally used for two-dimensional (2D) imaging. Our mesoscopic technique allows visualization of neuronal activity in a 3D manner with high temporal resolution. Results: We first demonstrated the depth-resolved capability of 3D mesoscopic imaging technology in Thy1-ChR2-YFP transgenic mice. Next, we recorded the long-range functional projections between sensory cortex (S1) and motor cortex (M1) in mice, in vivo, following single whisker deflection. Conclusions: The results show that mesoscopic imaging technique has the potential to investigate the layer-specific neural connectivity in the mouse cortex in vivo. Combination of mesoscopic imaging technique with optogenetic control strategy is a promising platform for determining depth-resolved interactions between cortical circuit elements.
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Affiliation(s)
- Qinggong Tang
- University of Oklahoma, Stephenson School of Biomedical Engineering, Norman, Oklahoma, United States
- University of Maryland, Fischell Department of Bioengineering, College Park, Maryland, United States
- Address all correspondence to Qinggong Tang, ; Reha S. Erzurumlu, ; Yu Chen,
| | - Vassiliy Tsytsarev
- University of Maryland School of Medicine, Department of Anatomy and Neurobiology, Baltimore, Maryland, United States
| | - Feng Yan
- University of Oklahoma, Stephenson School of Biomedical Engineering, Norman, Oklahoma, United States
| | - Chen Wang
- University of Oklahoma, Stephenson School of Biomedical Engineering, Norman, Oklahoma, United States
| | - Reha S. Erzurumlu
- University of Maryland School of Medicine, Department of Anatomy and Neurobiology, Baltimore, Maryland, United States
- Address all correspondence to Qinggong Tang, ; Reha S. Erzurumlu, ; Yu Chen,
| | - Yu Chen
- University of Maryland, Fischell Department of Bioengineering, College Park, Maryland, United States
- University of Massachusetts, Department of Biomedical Engineering, Amherst, Massachusetts, United States
- Address all correspondence to Qinggong Tang, ; Reha S. Erzurumlu, ; Yu Chen,
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Bag A, Ghorai PK. Enhancement of biocompatibility and photoacoustic contrast activity of metal clusters. J Mol Graph Model 2017; 75:220-232. [PMID: 28601707 DOI: 10.1016/j.jmgm.2017.05.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 05/12/2017] [Accepted: 05/16/2017] [Indexed: 01/23/2023]
Abstract
Organometallic carbonyl clusters (OMCC) of group VIII elements are water soluble, bio-compatible and stable high-contrast photoacoustic agents for live cell imaging. But, they have limited application due to weak absorption within 700-1000nm wavelength which is known as the biological window of absorption. In this article, we report that hexa-nuclear iron (Fe6) carbonyl cluster derivatized with sodium thio-propanoate has very good absorption within 700-1600nm wave length. This modeled compound is water soluble and bio-compatible. The bio-compatibility of this compound is tested through cytotoxicity, LogP and metabolic probability at CYP450-2D6 enzyme.
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Affiliation(s)
- Arijit Bag
- Department of Chemical Sciences, Indian Institute of Science Education and Research, Kolkata, Mohanpur 741246, WB, India
| | - Pradip Kr Ghorai
- Department of Chemical Sciences, Indian Institute of Science Education and Research, Kolkata, Mohanpur 741246, WB, India.
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Tang Q, Liu Y, Tsytsarev V, Lin J, Wang B, Kanniyappan U, Li Z, Chen Y. High-dynamic-range fluorescence laminar optical tomography (HDR-FLOT). BIOMEDICAL OPTICS EXPRESS 2017; 8:2124-2137. [PMID: 28736659 PMCID: PMC5516817 DOI: 10.1364/boe.8.002124] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 02/16/2017] [Accepted: 03/04/2017] [Indexed: 05/21/2023]
Abstract
Three-dimensional fluorescence laminar optical tomography (FLOT) can achieve resolutions of 100-200 µm and penetration depths of 2-3 mm. FLOT has been used in tissue engineering, neuroscience, as well as oncology. The limited dynamic range of the charge-coupled device-based system makes it difficult to image fluorescent samples with a large concentration difference, limits its penetration depth, and diminishes the quantitative accuracy of 3D reconstruction data. Here, incorporating the high-dynamic-range (HDR) method widely used in digital cameras, we present HDR-FLOT, increasing penetration depth and improving the ability to image fluorescent samples with a large concentration difference. The method was tested using an agar phantom and a B6 mouse for brain imaging in vivo.
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Affiliation(s)
- Qinggong Tang
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742 USA
- Contributed equally
| | - Yi Liu
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742 USA
- Contributed equally
| | - Vassiliy Tsytsarev
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Jonathan Lin
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742 USA
| | - Bohan Wang
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742 USA
| | - Udayakumar Kanniyappan
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742 USA
| | - Zhifang Li
- Key Laboratory of Optoelectronic Science and Technology for Medicine, Ministry of Education, College of Photonic and Electronic Engineering, Fujian Normal University, Fuzhou 350007, China
| | - Yu Chen
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742 USA
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Tsytsarev V, Akkentli F, Pumbo E, Tang Q, Chen Y, Erzurumlu RS, Papkovsky DB. Planar implantable sensor for in vivo measurement of cellular oxygen metabolism in brain tissue. J Neurosci Methods 2017; 281:1-6. [PMID: 28219725 DOI: 10.1016/j.jneumeth.2017.02.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 01/13/2017] [Accepted: 02/15/2017] [Indexed: 10/20/2022]
Abstract
BACKGROUND Brain imaging methods are continually improving. Imaging of the cerebral cortex is widely used in both animal experiments and charting human brain function in health and disease. Among the animal models, the rodent cerebral cortex has been widely used because of patterned neural representation of the whiskers on the snout and relative ease of activating cortical tissue with whisker stimulation. NEW METHOD We tested a new planar solid-state oxygen sensor comprising a polymeric film with a phosphorescent oxygen-sensitive coating on the working side, to monitor dynamics of oxygen metabolism in the cerebral cortex following sensory stimulation. RESULTS Sensory stimulation led to changes in oxygenation and deoxygenation processes of activated areas in the barrel cortex. We demonstrate the possibility of dynamic mapping of relative changes in oxygenation in live mouse brain tissue with such a sensor. COMPARISON WITH EXISTING METHOD Oxygenation-based functional magnetic resonance imaging (fMRI) is very effective method for functional brain mapping but have high costs and limited spatial resolution. Optical imaging of intrinsic signal (IOS) does not provide the required sensitivity, and voltage-sensitive dye optical imaging (VSDi) has limited applicability due to significant toxicity of the voltage-sensitive dye. Our planar solid-state oxygen sensor imaging approach circumvents these limitations, providing a simple optical contrast agent with low toxicity and rapid application. CONCLUSIONS The planar solid-state oxygen sensor described here can be used as a tool in visualization and real-time analysis of sensory-evoked neural activity in vivo. Further, this approach allows visualization of local neural activity with high temporal and spatial resolution.
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Affiliation(s)
- Vassiliy Tsytsarev
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 20 Penn Street, HSF-2, 21201 MD, Baltimore, USA.
| | - Fatih Akkentli
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 20 Penn Street, HSF-2, 21201 MD, Baltimore, USA.
| | - Elena Pumbo
- Center for Genetic Medicine, Children's National Medical Center, Washington DC, 111 Michigan Avenue, NW Washington, DC 20010, USA.
| | - Qinggong Tang
- Fischell Department of Bioengineering, University of Maryland, College Park, Kim Engineering Building, College Park, MD 20740, USA.
| | - Yu Chen
- Fischell Department of Bioengineering, University of Maryland, College Park, Kim Engineering Building, College Park, MD 20740, USA.
| | - Reha S Erzurumlu
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 20 Penn Street, HSF-2, 21201 MD, Baltimore, USA.
| | - Dmitri B Papkovsky
- School of Biochemistry and Cell Biology, University College Cork, Cavanagh Pharmacy Building 1.28, College Road, Cork, Ireland.
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Tang Q, Lin J, Tsytsarev V, Erzurumlu RS, Liu Y, Chen Y. Review of mesoscopic optical tomography for depth-resolved imaging of hemodynamic changes and neural activities. NEUROPHOTONICS 2017; 4:011009. [PMID: 27990452 PMCID: PMC5108095 DOI: 10.1117/1.nph.4.1.011009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 10/19/2016] [Indexed: 05/18/2023]
Abstract
Understanding the functional wiring of neural circuits and their patterns of activation following sensory stimulations is a fundamental task in the field of neuroscience. Furthermore, charting the activity patterns is undoubtedly important to elucidate how neural networks operate in the living brain. However, optical imaging must overcome the effects of light scattering in the tissue, which limit the light penetration depth and affect both the imaging quantitation and sensitivity. Laminar optical tomography (LOT) is a three-dimensional (3-D) in-vivo optical imaging technique that can be used for functional imaging. LOT can achieve both a resolution of 100 to [Formula: see text] and a penetration depth of 2 to 3 mm based either on absorption or fluorescence contrast, as well as large field-of-view and high acquisition speed. These advantages make LOT suitable for 3-D depth-resolved functional imaging of the neural functions in the brain and spinal cords. We review the basic principles and instrumentations of representative LOT systems, followed by recent applications of LOT on 3-D imaging of neural activities in the rat forepaw stimulation model and mouse whisker-barrel system.
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Affiliation(s)
- Qinggong Tang
- University of Maryland, Fischell Department of Bioengineering, 2334 Jeong H. Kim Engineering Building, College Park, Maryland 20742, United States
| | - Jonathan Lin
- University of Maryland, Fischell Department of Bioengineering, 2334 Jeong H. Kim Engineering Building, College Park, Maryland 20742, United States
| | - Vassiliy Tsytsarev
- University of Maryland School of Medicine, Department of Anatomy and Neurobiology, 20 Penn Street, HSFII S251, Baltimore, Maryland 21201, United States
| | - Reha S. Erzurumlu
- University of Maryland School of Medicine, Department of Anatomy and Neurobiology, 20 Penn Street, HSFII S251, Baltimore, Maryland 21201, United States
| | - Yi Liu
- University of Maryland, Fischell Department of Bioengineering, 2334 Jeong H. Kim Engineering Building, College Park, Maryland 20742, United States
| | - Yu Chen
- University of Maryland, Fischell Department of Bioengineering, 2334 Jeong H. Kim Engineering Building, College Park, Maryland 20742, United States
- Address all correspondence to: Yu Chen, E-mail:
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Gottschalk S, Fehm TF, Deán-Ben XL, Tsytsarev V, Razansky D. Correlation between volumetric oxygenation responses and electrophysiology identifies deep thalamocortical activity during epileptic seizures. NEUROPHOTONICS 2017; 4:011007. [PMID: 27725948 PMCID: PMC5050254 DOI: 10.1117/1.nph.4.1.011007] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 09/13/2016] [Indexed: 05/05/2023]
Abstract
Visualization of whole brain activity during epileptic seizures is essential for both fundamental research into the disease mechanisms and the development of efficient treatment strategies. It has been previously discussed that pathological synchronization originating from cortical areas may reinforce backpropagating signaling from the thalamic neurons, leading to massive seizures through enhancement of high frequency neural activity in the thalamocortical loop. However, the study of deep brain neural activity is challenging with the existing functional neuroimaging methods due to lack of adequate spatiotemporal resolution or otherwise insufficient penetration into subcortical areas. To investigate the role of thalamocortical activity during epileptic seizures, we developed a new functional neuroimaging framework based on spatiotemporal correlation of volumetric optoacoustic hemodynamic responses with the concurrent electroencephalogram recordings and anatomical brain landmarks. The method is shown to be capable of accurate three-dimensional mapping of the onset, spread, and termination of the epileptiform events in a 4-aminopyridine acute model of focal epilepsy. Our study is the first to demonstrate entirely noninvasive real-time visualization of synchronized epileptic foci in the whole mouse brain, including the neocortex and subcortical structures, thus opening new vistas in systematic studies toward the understanding of brain signaling and the origins of neurological disorders.
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Affiliation(s)
- Sven Gottschalk
- Institute for Biological and Medical Imaging (IBMI), Helmholtz Center Munich, Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany
| | - Thomas Felix Fehm
- Institute for Biological and Medical Imaging (IBMI), Helmholtz Center Munich, Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany
- Technical University of Munich, Faculty of Medicine, Ismaninger Str. 22, 81675 Munich, Germany
| | - Xose Luís Deán-Ben
- Institute for Biological and Medical Imaging (IBMI), Helmholtz Center Munich, Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany
| | - Vassiliy Tsytsarev
- University of Maryland School of Medicine, Department of Anatomy and Neurobiology, 20 Penn Street, HSF II, Baltimore, Maryland 21201, United States
| | - Daniel Razansky
- Institute for Biological and Medical Imaging (IBMI), Helmholtz Center Munich, Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany
- Technical University of Munich, Faculty of Medicine, Ismaninger Str. 22, 81675 Munich, Germany
- Address all correspondence to: Daniel Razansky, E-mail:
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In Vivo Mesoscopic Voltage-Sensitive Dye Imaging of Brain Activation. Sci Rep 2016; 6:25269. [PMID: 27125318 PMCID: PMC4850485 DOI: 10.1038/srep25269] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 04/14/2016] [Indexed: 02/02/2023] Open
Abstract
Functional mapping of brain activity is important in elucidating how neural networks operate in the living brain. The whisker sensory system of rodents is an excellent model to study peripherally evoked neural activity in the central nervous system. Each facial whisker is represented by discrete modules of neurons all along the pathway leading to the neocortex. These modules are called "barrels" in layer 4 of the primary somatosensory cortex. Their location (approximately 300-500 μm below cortical surface) allows for convenient imaging of whisker-evoked neural activity in vivo. Fluorescence laminar optical tomography (FLOT) provides depth-resolved fluorescence molecular information with an imaging depth of a few millimeters. Angled illumination and detection configurations can improve both resolution and penetration depth. We applied angled FLOT (aFLOT) to record 3D neural activities evoked in the whisker system of mice by deflection of a single whisker in vivo. A 100 μm capillary and a pair of microelectrodes were inserted to the mouse brain to test the capability of the imaging system. The results show that it is possible to obtain 3D functional maps of the sensory periphery in the brain. This approach can be broadly applicable to functional imaging of other brain structures.
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Tsytsarev V, Pumbo E, Tang Q, Chen CW, Kalchenko V, Chen Y. Study of the cortical representation of whisker frequency selectivity using voltage-sensitive dye optical imaging. INTRAVITAL 2016; 5:e1142637. [PMID: 28243518 DOI: 10.1080/21659087.2016.1142637] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Revised: 01/06/2016] [Accepted: 01/08/2016] [Indexed: 12/17/2022]
Abstract
The facial whiskers of rodents act as a high-resolution tactile apparatus that allow the animal to detect the finest details of its environment. Previously it was shown that whisker-sensitive neurons in the somatosensory cortex show frequency selectivity to small amplitude stimuli, An intravital voltage-sensitive dye optical imaging (VSDi) method in combination with the different frequency whisker stimulation was used in order to visualize neural activity in the mice somatosensory cortex in response to the stimulation of a single whisker by different frequencies. Using the intravital voltage-sensitive dye optical imaging (VSDi) method in combination with the different frequency whisker stimulation we visualized neural activity in the mice somatosensory cortex in response to the stimulation of a single whisker by different frequencies. We found that whisker stimuli with different frequencies led to different optical signals in the barrel field. Our results provide evidence that different neurons of the barrel cortex have different frequency preferences. This supports prior research that whisker deflections cause responses in cortical neurons within the barrel field according to the frequency of the stimulation. Many studies of the whisker frequency selectivity were performed using unit recording but to map spatial organization, imaging methods are essential. In the work described in the present paper, we take a serious step toward detailed functional mapping of the somatosensory cortex using VSDi. To our knowledge, this is the first demonstration of whisker frequency sensitivity and selectivity of barrel cortex neurons with optical imaging methods.
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Affiliation(s)
- Vassiliy Tsytsarev
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine , Baltimore, MD, USA
| | - Elena Pumbo
- Center for Genetic Medicine, Children's National Medical Center , Washington, DC, USA
| | - Qinggong Tang
- Department of Bioengineering, University of Maryland , College Park, MD, USA
| | - Chao-Wei Chen
- Department of Bioengineering, University of Maryland , College Park, MD, USA
| | - Vyacheslav Kalchenko
- Department of Veterinary Resources, Weizmann Institute of Science , Rehovot, Israel
| | - Yu Chen
- Department of Bioengineering, University of Maryland , College Park, MD, USA
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Tang Q, Tsytsarev V, Liang CP, Akkentli F, Erzurumlu RS, Chen Y. In Vivo Voltage-Sensitive Dye Imaging of Subcortical Brain Function. Sci Rep 2015; 5:17325. [PMID: 26612326 PMCID: PMC4661443 DOI: 10.1038/srep17325] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 10/28/2015] [Indexed: 12/29/2022] Open
Abstract
The whisker system of rodents is an excellent model to study peripherally evoked neural activity in the brain. Discrete neural modules represent each whisker in the somatosensory cortex (“barrels”), thalamus (“barreloids”), and brain stem (“barrelettes”). Stimulation of a single whisker evokes neural activity sequentially in its corresponding barrelette, barreloid, and barrel. Conventional optical imaging of functional activation in the brain is limited to surface structures such as the cerebral cortex. To access subcortical structures and image sensory-evoked neural activity, we designed a needle-based optical system using gradient-index (GRIN) rod lens. We performed voltage-sensitive dye imaging (VSDi) with GRIN rod lens to visualize neural activity evoked in the thalamic barreloids by deflection of whiskers in vivo. We stimulated several whiskers together to determine the sensitivity of our approach in differentiating between different barreloid responses. We also carried out stimulation of different whiskers at different times. Finally, we used muscimol in the barrel cortex to silence the corticothalamic inputs while imaging in the thalamus. Our results show that it is possible to obtain functional maps of the sensory periphery in deep brain structures such as the thalamic barreloids. Our approach can be broadly applicable to functional imaging of other core brain structures.
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Affiliation(s)
- Qinggong Tang
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742 USA
| | - Vassiliy Tsytsarev
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742 USA.,Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Chia-Pin Liang
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742 USA
| | - Fatih Akkentli
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Reha S Erzurumlu
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Yu Chen
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742 USA
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Milej D, Janusek D, Gerega A, Wojtkiewicz S, Sawosz P, Treszczanowicz J, Weigl W, Liebert A. Optimization of the method for assessment of brain perfusion in humans using contrast-enhanced reflectometry: multidistance time-resolved measurements. JOURNAL OF BIOMEDICAL OPTICS 2015; 20:106013. [PMID: 26509415 DOI: 10.1117/1.jbo.20.10.106013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 10/06/2015] [Indexed: 05/24/2023]
Abstract
The aim of the study was to determine optimal measurement conditions for assessment of brain perfusion with the use of optical contrast agent and time-resolved diffuse reflectometry in the near-infrared wavelength range. The source-detector separation at which the distribution of time of flights (DTOF) of photons provided useful information on the inflow of the contrast agent to the intracerebral brain tissue compartments was determined. Series of Monte Carlo simulations was performed in which the inflow and washout of the dye in extra- and intracerebral tissue compartments was modeled and the DTOFs were obtained at different source-detector separations. Furthermore, tests on diffuse phantoms were carried out using a time-resolved setup allowing the measurement of DTOFs at 16 source-detector separations. Finally, the setup was applied in experiments carried out on the heads of adult volunteers during intravenous injection of indocyanine green. Analysis of statistical moments of the measured DTOFs showed that the source-detector separation of 6 cm is recommended for monitoring of inflow of optical contrast to the intracerebral brain tissue compartments with the use of continuous wave reflectometry, whereas the separation of 4 cm is enough when the higher-order moments of DTOFs are available.
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Affiliation(s)
- Daniel Milej
- Polish Academy of Sciences, Nalecz Institute of Biocybernetics and Biomedical Engineering, 4Ks. Trojdena Street 02-109 Warsaw, Poland
| | - Dariusz Janusek
- Polish Academy of Sciences, Nalecz Institute of Biocybernetics and Biomedical Engineering, 4Ks. Trojdena Street 02-109 Warsaw, Poland
| | - Anna Gerega
- Polish Academy of Sciences, Nalecz Institute of Biocybernetics and Biomedical Engineering, 4Ks. Trojdena Street 02-109 Warsaw, Poland
| | - Stanislaw Wojtkiewicz
- Polish Academy of Sciences, Nalecz Institute of Biocybernetics and Biomedical Engineering, 4Ks. Trojdena Street 02-109 Warsaw, Poland
| | - Piotr Sawosz
- Polish Academy of Sciences, Nalecz Institute of Biocybernetics and Biomedical Engineering, 4Ks. Trojdena Street 02-109 Warsaw, Poland
| | - Joanna Treszczanowicz
- Warsaw Praski Hospital, Department of Intensive Care and Anesthesiology, 67 Al. Solidarnosci Street, 03-401 Warsaw, Poland
| | - Wojciech Weigl
- Warsaw Praski Hospital, Department of Intensive Care and Anesthesiology, 67 Al. Solidarnosci Street, 03-401 Warsaw, PolandcUppsala University, Department of Surgical Sciences/Anesthesiology and Intensive Care, 751 85 Uppsala, Sweden
| | - Adam Liebert
- Polish Academy of Sciences, Nalecz Institute of Biocybernetics and Biomedical Engineering, 4Ks. Trojdena Street 02-109 Warsaw, Poland
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Liao LD, Li ML, Lai HY, Chen YY, Thakor NV. Study of neurovascular coupling functions for transient focal cerebral ischemia in rats using electrocorticography functional photoacoustic microscopy (ECoG-fPAM). ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2015; 2013:1799-802. [PMID: 24110058 DOI: 10.1109/embc.2013.6609871] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Recently, the functional photoacoustic microscopy (fPAM) system has been proven to be a reliable imaging technique for measuring the total hemoglobin concentration (HbT), cerebral blood volume (CBV) and hemoglobin oxygen saturation (SO2) in single cerebral blood vessels of rats. In this study, we report for the first time the combination of electrocorticography (ECoG) recordings and fPAM (ECoG-fPAM) to investigate functional hemodynamic changes and neuro-vascular coupling in single cortical arterioles of rats with electrical forepaw stimulation after photothrombotic stroke. Because of the optical focusing nature of our fPAM system, photo-induced ischemic stroke targeting on single cortical arterioles can be easily conducted with simple adaptation. Functional cerebral HbT, CBV and SO2 changes associated with the induced stroke in selected arterioles from the anterior cerebral artery system were imaged with a 36 × 65-µm spatial resolution. The ECoG-fPAM system complements existing imaging techniques and has the potential to offer a favorable tool for explicitly studying cerebral hemodynamics and neuro-vascular coupling in small animal models of photo-induced ischemic stroke.
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Liao LD, Liu YH, Lai HY, Bandla A, Shih YYI, Chen YY, Thakor NV. Rescue of cortical neurovascular functions during the hyperacute phase of ischemia by peripheral sensory stimulation. Neurobiol Dis 2015; 75:53-63. [DOI: 10.1016/j.nbd.2014.12.022] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 12/07/2014] [Accepted: 12/23/2014] [Indexed: 10/24/2022] Open
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14
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Bag A, Ghorai PK. Computational investigation of the ligand field effect to improve the photoacoustic properties of organometallic carbonyl clusters. RSC Adv 2015. [DOI: 10.1039/c5ra01757b] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Organometallic nitrosyl carbonyl clusters are stable and better high-contrast photoacoustic contrast agents (PACAs) than organometallic carbonyl clusters.
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Affiliation(s)
- Arijit Bag
- Indian Institute of Science Education and Research Kolkata
- India
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15
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Jeon M, Kim J, Kim C. Multiplane spectroscopic whole-body photoacoustic imaging of small animals in vivo. Med Biol Eng Comput 2014; 54:283-94. [PMID: 25115270 DOI: 10.1007/s11517-014-1182-6] [Citation(s) in RCA: 97] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Accepted: 07/30/2014] [Indexed: 02/04/2023]
Abstract
We have successfully developed a multiscale acoustic-resolution photoacoustic tomography system in a single imaging platform. By switching between ultrasound transducers (center frequencies 5 and 40 MHz) and optical condensers, we have photoacoustically imaged microvasculatures of small animals in vivo at different scales. Further, we have extended the field of view of our imaging system to entire bodies of small animals. At different imaging planes, we have noninvasively imaged the major blood vessels (e.g., descending aorta, intercostal vessels, cephalic vessels, brachial vessels, femoral vessels, popliteal vessels, lateral marginal vessels, cranial mesenteric vessels, mammalian vessels, carotid artery, jugular vein, subclavian vessels, iliac vessels, and caudal vessels) as well as intact internal organs (e.g., spleen, liver, kidney, intestine, cecum, and spinal cord) of the animals in vivo. The spectroscopic whole-body photoacoustic imaging clearly reveals the spectral responses of the internal structures. Similar to other existing preclinical whole-body imaging systems, this whole-body photoacoustic tomography can be a useful tool for small-animal research.
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Affiliation(s)
- Mansik Jeon
- Departments of Creative IT Engineering and Electrical Engineering, Future IT Innovation Laboratory, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk, 790-784, Republic of Korea
| | - Jeesu Kim
- Departments of Creative IT Engineering and Electrical Engineering, Future IT Innovation Laboratory, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk, 790-784, Republic of Korea
| | - Chulhong Kim
- Departments of Creative IT Engineering and Electrical Engineering, Future IT Innovation Laboratory, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk, 790-784, Republic of Korea.
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16
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Ogawa Y, Kotani K, Jimbo Y. Relationship between working memory performance and neural activation measured using near-infrared spectroscopy. Brain Behav 2014; 4:544-51. [PMID: 25161821 PMCID: PMC4128036 DOI: 10.1002/brb3.238] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Revised: 04/20/2014] [Accepted: 04/30/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Working memory (WM) is a key function for various cognitive processes. Near-infrared spectroscopy (NIRS) is a powerful technique for noninvasive functional imaging. However, a study has yet to be published on the application of NIRS for evaluating WM performance. The objective was to evaluate NIRS for measuring WM performance. METHODS Subjects were trained to perform a visuospatial WM task. Eight channels on the lateral prefrontal cortex were analyzed. We asked the following three questions: (1) Does WM performance correlate with NIRS signal amplitudes? (2) What are the differences in NIRS amplitudes between correct- and incorrect-WM tasks? (3) Is there a correlation between WM performance and NIRS amplitudes in only correct-WM tasks? RESULTS NIRS activation in all channels correlated with WM performance (P < 0.05). There was a statistically significant difference (P < 0.05) in seven channels between NIRS amplitude in correct- and incorrect-WM tasks. NIRS activation of the delay time averaged with only correct-WM tasks, correlated with WM performance in six channels (P < 0.05). CONCLUSIONS Subjects with better WM performance have higher levels of oxyhemoglobin activation compared with control trials in the WM delay time, and our results suggest that NIRS will be useful for measuring the WM performance.
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Affiliation(s)
- Yutaro Ogawa
- Graduate School of Frontier Science, The University of Tokyo Chiba, Japan
| | - Kiyoshi Kotani
- Graduate School of Frontier Science, The University of Tokyo Chiba, Japan
| | - Yasuhiko Jimbo
- Graduate School of Frontier Science, The University of Tokyo Chiba, Japan
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17
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Liao LD, Bandla A, Ling JM, Liu YH, Kuo LW, Chen YY, King NKK, Lai HY, Lin YR, Thakor NV. Improving neurovascular outcomes with bilateral forepaw stimulation in a rat photothrombotic ischemic stroke model. NEUROPHOTONICS 2014; 1:011007. [PMID: 26157965 PMCID: PMC4478786 DOI: 10.1117/1.nph.1.1.011007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 05/01/2014] [Accepted: 05/13/2014] [Indexed: 05/19/2023]
Abstract
Restoring perfusion to the penumbra during the hyperacute phase of ischemic stroke is a key goal of neuroprotection. Thrombolysis is currently the only approved treatment for ischemic stroke. However, its use is limited by the narrow therapeutic window and side effect of bleeding. Therefore, other interventions are desired that could potentially increase the perfusion of the penumbra. Here, we hypothesized that bilateral peripheral electrical stimulation will improve cerebral perfusion and restore cortical neurovascular response. We assess the outcomes of bilateral forepaw electrical stimulation at intensities of 2 and 4 mA, administered either unilaterally or bilaterally. We developed a combined electrocorticogram (ECoG)-functional photoacoustic microscopy (fPAM) system to evaluate the relative changes in cerebral hemodynamic function and electrophysiologic response to acute, focal stroke. The fPAM system is used for cerebral blood volume (CBV) and hemoglobin oxygen saturation ([Formula: see text]) and the ECoG for neural activity, namely somatosensory-evoked potential (SSEP), interhemispheric coherence, and alpha-delta ratio (ADR) in response to forepaw stimulation. Our results confirmed the neuroprotective effect of bilateral forepaw stimulation at 2 mA as indicated by the 82% recovery of ADR and 95% improvement in perfusion into the region of penumbra. This experimental model can be used to study other potential interventions such as therapeutic hypertension and hypercarbia.
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Affiliation(s)
- Lun-De Liao
- National University of Singapore, Singapore Institute for Neurotechnology (SINAPSE), 28 Medical Drive, #05-COR, Singapore 117456, Singapore
- Address all correspondence to: Lun-De Liao, E-mail: or
| | - Aishwarya Bandla
- National University of Singapore, Singapore Institute for Neurotechnology (SINAPSE), 28 Medical Drive, #05-COR, Singapore 117456, Singapore
- National University of Singapore, Department of Biomedical Engineering, 9 Engineering Drive 1, Block EA #03-12, Singapore 117575, Singapore
| | - Ji Min Ling
- National University of Singapore, Singapore Institute for Neurotechnology (SINAPSE), 28 Medical Drive, #05-COR, Singapore 117456, Singapore
- National Neuroscience Institute, Department of Neurosurgery, 11 Jalan Tan Tock Seng, Singapore 308433, Singapore
| | - Yu-Hang Liu
- National University of Singapore, Singapore Institute for Neurotechnology (SINAPSE), 28 Medical Drive, #05-COR, Singapore 117456, Singapore
- National University of Singapore, Department of Electrical & Computer Engineering, Block E4, Level 5, Room 45, 4 Engineering Drive 3, Singapore 117583, Singapore
| | - Li-Wei Kuo
- National Health Research Institutes, Institute of Biomedical Engineering and Nanomedicine, 35, Keyan Road, Zhunan Town, Miaoli County 350, Taiwan
| | - You-Yin Chen
- National Yang Ming University, Department of Biomedical Engineering, No. 155, Sec. 2, Linong St., Taipei, Taiwan 112
| | - Nicolas KK King
- National Neuroscience Institute, Department of Neurosurgery, 11 Jalan Tan Tock Seng, Singapore 308433, Singapore
| | - Hsin-Yi Lai
- Chang Gung Memorial Hospital and Chang Gung University, Department of Physical Medicine and Rehabilitation, Taoyuan 333, Taiwan
| | - Yan-Ren Lin
- Changhua Christian Hospital, Department of Emergency Medicine, 135 Nanshsiao Street, Changhua, Taiwan 500
| | - Nitish V. Thakor
- National University of Singapore, Singapore Institute for Neurotechnology (SINAPSE), 28 Medical Drive, #05-COR, Singapore 117456, Singapore
- National University of Singapore, Department of Biomedical Engineering, 9 Engineering Drive 1, Block EA #03-12, Singapore 117575, Singapore
- National University of Singapore, Department of Electrical & Computer Engineering, Block E4, Level 5, Room 45, 4 Engineering Drive 3, Singapore 117583, Singapore
- Johns Hopkins University, Department of Biomedical Engineering, Traylor 701/720 Rutland Avenue, Baltimore, Maryland 21205
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18
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Wang B, Xiao J, Jiang H. Simultaneous real-time 3D photoacoustic tomography and EEG for neurovascular coupling study in an animal model of epilepsy. J Neural Eng 2014; 11:046013. [PMID: 24940747 DOI: 10.1088/1741-2560/11/4/046013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
OBJECTIVE Neurovascular coupling in epilepsy is poorly understood; its study requires simultaneous monitoring of hemodynamic changes and neural activity in the brain. APPROACH Here for the first time we present a combined real-time 3D photoacoustic tomography (PAT) and electrophysiology/electroencephalography (EEG) system for the study of neurovascular coupling in epilepsy, whose ability was demonstrated with a pentylenetetrazol (PTZ) induced generalized seizure model in rats. Two groups of experiments were carried out with different wavelengths to detect the changes of oxy-hemoglobin (HbO2) and deoxy-hemoglobin (HbR) signals in the rat brain. We extracted the average PAT signals of the superior sagittal sinus (SSS), and compared them with the EEG signal. MAIN RESULTS Results showed that the seizure process can be divided into three stages. A 'dip' lasting for 1-2 min in the first stage and the following hyperfusion in the second stage were observed. The HbO2 signal and the HbR signal were generally negatively correlated. The change of blood flow was also estimated. All the acquired results here were in accordance with other published results. SIGNIFICANCE Compared to other existing functional neuroimaging tools, the method proposed here enables reliable tracking of hemodynamic signal with both high spatial and high temporal resolution in 3D, so it is more suitable for neurovascular coupling study of epilepsy.
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Affiliation(s)
- Bo Wang
- J Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, USA
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19
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Hwang HJ, Lim JH, Kim DW, Im CH. Evaluation of various mental task combinations for near-infrared spectroscopy-based brain-computer interfaces. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:77005. [PMID: 25036216 DOI: 10.1117/1.jbo.19.7.077005] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2014] [Accepted: 06/20/2014] [Indexed: 05/15/2023]
Abstract
A number of recent studies have demonstrated that near-infrared spectroscopy (NIRS) is a promisingneuroimaging modality for brain-computer interfaces (BCIs). So far, most NIRS-based BCI studies have focusedon enhancing the accuracy of the classification of different mental tasks. In the present study, we evaluated theperformances of a variety of mental task combinations in order to determine the mental task pairs that are bestsuited for customized NIRS-based BCIs. To this end, we recorded event-related hemodynamic responses whileseven participants performed eight different mental tasks. Classification accuracies were then estimated for allpossible pairs of the eight mental tasks (8C2 = 28). Based on this analysis, mental task combinations with relatively high classification accuracies frequently included the following three mental tasks: “mental multiplication,” “mental rotation,” and “right-hand motor imagery.” Specifically, mental task combinations consisting of two of these three mental tasks showed the highest mean classification accuracies. It is expected that our results will be a useful reference to reduce the time needed for preliminary tests when discovering individual-specific mental task combinations.
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Affiliation(s)
- Han-Jeong Hwang
- Hanyang University, Department of Biomedical Engineering, Seoul 133-791, Republic of KoreabBerlin Institute of Technology, Machine Learning Group, Marchstrasse 23, Berlin 10587, Germany
| | - Jeong-Hwan Lim
- Hanyang University, Department of Biomedical Engineering, Seoul 133-791, Republic of Korea
| | - Do-Won Kim
- Hanyang University, Department of Biomedical Engineering, Seoul 133-791, Republic of Korea
| | - Chang-Hwan Im
- Hanyang University, Department of Biomedical Engineering, Seoul 133-791, Republic of Korea
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20
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Kong KV, Liao LD, Lam Z, Thakor NV, Leong WK, Olivo M. Organometallic carbonyl clusters: a new class of contrast agents for photoacoustic cerebral vascular imaging. Chem Commun (Camb) 2014; 50:2601-3. [DOI: 10.1039/c3cc48529c] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The strong photoacoustic signal of a water soluble osmium carbonyl cluster allowed it to be employed as a contrast agent to image the cerebral vasculature of a rat. The high stability and low toxicity of such a compound make it an excellent candidate in such biomedical applications.
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Affiliation(s)
- Kien Voon Kong
- Singapore Bioimaging Consortium
- Agency for Science
- Technology and Research
- Singapore
| | - Lun-De Liao
- Singapore Institute for Neurotechnology (SINAPSE)
- National University of Singapore
- Singapore
| | - Zhiyong Lam
- Division of Chemistry & Biological Chemistry
- Nanyang Technological University
- Singapore
| | - Nitish V. Thakor
- Singapore Institute for Neurotechnology (SINAPSE)
- National University of Singapore
- Singapore
- Department of Biomedical Engineering
- John Hopkins University
| | - Weng Kee Leong
- Division of Chemistry & Biological Chemistry
- Nanyang Technological University
- Singapore
| | - Malini Olivo
- Singapore Bioimaging Consortium
- Agency for Science
- Technology and Research
- Singapore
- School of Physics
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21
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Liao LD, Orellana J, Liu YH, Lin YR, Vipin A, Thakor NV, Shen K, Wilder-Smith E. Imaging of temperature dependent hemodynamics in the rat sciatic nerve by functional photoacoustic microscopy. Biomed Eng Online 2013; 12:120. [PMID: 24245952 PMCID: PMC4225521 DOI: 10.1186/1475-925x-12-120] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Accepted: 10/09/2013] [Indexed: 02/08/2023] Open
Abstract
Background Vascular hemodynamics is central to the regulation of neuro-metabolism and plays important roles in peripheral nerves diseases and their prevention. However, at present there are only a few techniques capable of directly measuring peripheral nerve vascular hemodynamics. Method Here, we investigate the use of dark-field functional photoacoustic microscopy (fPAM) for intrinsic visualizing of the relative hemodynamics of the rat sciatic nerve in response to localized temperature modulation (i.e., cooling and rewarming). Results and conclusion Our main results show that the relative functional total hemoglobin concentration (HbT) is more significantly correlated with localized temperature changes than the hemoglobin oxygen saturation (SO2) changes in the sciatic nerve. Our study also indicates that the relative HbT changes are better markers of neuronal activation than SO2 during nerve temperature changes. Our results show that fPAM is a promising candidate for in vivo imaging of peripheral nerve hemodynamics without the use of contrast agents. Additionally, this technique may shed light on the neuroprotective effect of hypothermia on peripheral nerves by visualizing their intrinsic hemodynamics.
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Affiliation(s)
| | | | | | | | | | | | - Kaiquan Shen
- Singapore Institute for Neurotechnology (SINAPSE), National University of Singapore, 28 Medical Drive, #05-COR, Singapore 117456, Singapore.
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22
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Chen S, Pei W, Gui Q, Chen Y, Zhao S, Wang H, Chen H. A fiber-based implantable multi-optrode array with contiguous optical and electrical sites. J Neural Eng 2013; 10:046020. [DOI: 10.1088/1741-2560/10/4/046020] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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23
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Liao LD, Tsytsarev V, Delgado-Martínez I, Li ML, Erzurumlu R, Vipin A, Orellana J, Lin YR, Lai HY, Chen YY, Thakor NV. Neurovascular coupling: in vivo optical techniques for functional brain imaging. Biomed Eng Online 2013; 12:38. [PMID: 23631798 PMCID: PMC3655834 DOI: 10.1186/1475-925x-12-38] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Accepted: 03/25/2013] [Indexed: 01/21/2023] Open
Abstract
Optical imaging techniques reflect different biochemical processes in the brain, which is closely related with neural activity. Scientists and clinicians employ a variety of optical imaging technologies to visualize and study the relationship between neurons, glial cells and blood vessels. In this paper, we present an overview of the current optical approaches used for the in vivo imaging of neurovascular coupling events in small animal models. These techniques include 2-photon microscopy, laser speckle contrast imaging (LSCI), voltage-sensitive dye imaging (VSDi), functional photoacoustic microscopy (fPAM), functional near-infrared spectroscopy imaging (fNIRS) and multimodal imaging techniques. The basic principles of each technique are described in detail, followed by examples of current applications from cutting-edge studies of cerebral neurovascular coupling functions and metabolic. Moreover, we provide a glimpse of the possible ways in which these techniques might be translated to human studies for clinical investigations of pathophysiology and disease. In vivo optical imaging techniques continue to expand and evolve, allowing us to discover fundamental basis of neurovascular coupling roles in cerebral physiology and pathophysiology.
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Affiliation(s)
- Lun-De Liao
- Singapore Institute for Neurotechnology (SINAPSE), National University of Singapore, 28 Medical Drive, #05-COR, Singapore 117456, Singapore
| | - Vassiliy Tsytsarev
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 20 Penn street, HSF-2, Baltimore, MD 21201, USA
| | - Ignacio Delgado-Martínez
- Singapore Institute for Neurotechnology (SINAPSE), National University of Singapore, 28 Medical Drive, #05-COR, Singapore 117456, Singapore
| | - Meng-Lin Li
- Department of Electrical Engineering, National Tsing Hua University, No. 101, Sec. 2, Kuang-Fu Rd, Hsinchu 300, R.O.C, Taiwan
| | - Reha Erzurumlu
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 20 Penn street, HSF-2, Baltimore, MD 21201, USA
| | - Ashwati Vipin
- Singapore Institute for Neurotechnology (SINAPSE), National University of Singapore, 28 Medical Drive, #05-COR, Singapore 117456, Singapore
| | - Josue Orellana
- Singapore Institute for Neurotechnology (SINAPSE), National University of Singapore, 28 Medical Drive, #05-COR, Singapore 117456, Singapore
| | - Yan-Ren Lin
- Department of Emergency Medicine, Changhua Christian Hospital, 135 Nanshsiao Street, Changhua 500, R.O.C, Taiwan
| | - Hsin-Yi Lai
- Department of Physical Medicine and Rehabilitation, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan 333, R.O.C, Taiwan
| | - You-Yin Chen
- Department of Biomedical Engineering, National Yang Ming University, No.155, Sec.2, Linong St, Taipei 112, R.O.C, Taiwan
| | - Nitish V Thakor
- Singapore Institute for Neurotechnology (SINAPSE), National University of Singapore, 28 Medical Drive, #05-COR, Singapore 117456, Singapore
- Department of Biomedical Engineering, Johns Hopkins University, Traylor 701/720 Rutland Ave, Baltimore, MD 21205, USA
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Tsytsarev V, Rao B, Maslov KI, Li L, Wang LV. Photoacoustic and optical coherence tomography of epilepsy with high temporal and spatial resolution and dual optical contrasts. J Neurosci Methods 2013; 216:142-5. [PMID: 23603664 DOI: 10.1016/j.jneumeth.2013.04.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Revised: 04/01/2013] [Accepted: 04/04/2013] [Indexed: 01/26/2023]
Abstract
Epilepsy mapping with high spatial and temporal resolution has great significance for both fundamental research on epileptic neurons and the clinical management of epilepsy. In this communication, we demonstrate for the first time in vivo epilepsy mapping with high spatial and temporal resolution and dual optical contrasts in an animal model. Through the variations of a depthresolved optical coherence tomography signal with optical scattering contrast, we observed that epileptic neuron activities modulated the optical refractive index of epileptic neurons and their surrounding tissue. Simultaneously, through neurovasculature coupling mechanisms and optical absorption contrast, we used photoacoustic signals to document the hemodynamic changes of the microvasculature surrounding the epileptic neurons. The epilepsy mapping results were confirmed by a simultaneously recorded electroencephalogram signal during epileptic seizure. Our new epilepsy mapping tool, with high temporal and spatial resolution and dual optical contrasts, may find many applications, such as drug development and epilepsy surgery.
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Affiliation(s)
- Vassiliy Tsytsarev
- Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA
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25
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Lenkov DN, Volnova AB, Pope ARD, Tsytsarev V. Advantages and limitations of brain imaging methods in the research of absence epilepsy in humans and animal models. J Neurosci Methods 2012; 212:195-202. [PMID: 23137652 DOI: 10.1016/j.jneumeth.2012.10.018] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Revised: 10/24/2012] [Accepted: 10/25/2012] [Indexed: 12/18/2022]
Abstract
The purpose of this review is to analyze research possibilities and limitations of several methods, technical tools and their combinations for elucidation of absence epilepsy mechanisms, particularly the childhood absences. Despite the notable collection of simultaneous recording of clinical electroencephalography (EEG) and behavioral changes in relation to absence seizures, shortcomings of scalp EEG in both spatial resolution and precise detection of subcortical centers have limited the understanding of the fundamental mechanisms of altered brain function during and after recurrent epileptic paroxysms. Therefore, in the past decade, EEG recordings have often been combined with simultaneous imaging methods in epilepsy studies. Among imaging methods, the following ones are used regularly: functional magnetic resonance imaging (fMRI), positron-emission tomography (PET), low-resolution electromagnetic tomography (LORETA), single photon emission spectroscopy (SPECT), near-infrared spectroscopy (NIRS), and optical imaging of intrinsic signals (IOS). In addition, voltage-sensitive dye optical imaging method and even photoacoustic microscopy can be applied to animal models of epilepsy. Samplings of some of the most relevant data obtained by the above methods are presented. It appears that the elaboration of more adequate animal models of the patterns of absence seizures during the early postnatal period is necessary for better correspondence of human and animal absence phenomena.
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Affiliation(s)
- Dmitry N Lenkov
- Nevsky Center of Scientific Collaboration-Saint Petersburg, Razjezshaya 43/1 Liter A, Suite 8N, Saint Petersburg 192119, Russia
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