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Zhdanov AV, Sen R, Devoy C, Li L, Tangney M, Papkovsky DB. Analysis of tumour oxygenation in model animals on a phosphorescence lifetime based macro-imager. Sci Rep 2023; 13:18732. [PMID: 37907625 PMCID: PMC10618169 DOI: 10.1038/s41598-023-46224-7] [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: 11/30/2022] [Accepted: 10/30/2023] [Indexed: 11/02/2023] Open
Abstract
Monitoring of tissue O2 is essential for cancer development and treatment, as hypoxic tumour regions develop resistance to radio- and chemotherapy. We describe a minimally invasive technique for the monitoring of tissue oxygenation in developing grafted tumours, which uses the new phosphorescence lifetime based Tpx3Cam imager. CT26 cells stained with a near-infrared emitting nanoparticulate O2 probe NanO2-IR were injected into mice to produce grafted tumours with characteristic phosphorescence. The tumours were allowed to develop for 3, 7, 10 and 17 days, with O2 imaging experiments performed on live and euthanised animals at different time points. Despite a marked trend towards decreased O2 in dead animals, their tumour areas produced phosphorescence lifetime values between 44 and 47 µs, which corresponded to hypoxic tissue with 5-20 μM O2. After the O2 imaging in animals, confocal Phosphorescence Lifetime Imaging Microscopy was conducted to examine the distribution of NanO2-IR probe in the tumours, which were excised, fixed and sliced for the purpose. The probe remained visible as bright and discrete 'islands' embedded in the tumour tissue until day 17 of tumour growth. Overall, this O2 macro-imaging method using NanO2-IR holds promise for long-term studies with grafted tumours in live animal models, providing quantitative 2D mapping of tissue O2.
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Affiliation(s)
- Alexander V Zhdanov
- School of Biochemistry and Cell Biology, University College Cork, Pharmacy Building, College Road, Cork, Ireland
| | - Rajannya Sen
- School of Biochemistry and Cell Biology, University College Cork, Pharmacy Building, College Road, Cork, Ireland
| | - Ciaran Devoy
- Cancer Research @UCC, University College Cork, Cork, Ireland
| | - Liang Li
- School of Biochemistry and Cell Biology, University College Cork, Pharmacy Building, College Road, Cork, Ireland
| | - Mark Tangney
- Cancer Research @UCC, University College Cork, Cork, Ireland
| | - Dmitri B Papkovsky
- School of Biochemistry and Cell Biology, University College Cork, Pharmacy Building, College Road, Cork, Ireland.
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Suzuki T, Oishi N, Fukuyama H. Simultaneous infrared thermal imaging and laser speckle imaging of brain temperature and cerebral blood flow in rats. JOURNAL OF BIOMEDICAL OPTICS 2018; 24:1-11. [PMID: 30468045 PMCID: PMC6975233 DOI: 10.1117/1.jbo.24.3.031014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 11/05/2018] [Indexed: 06/09/2023]
Abstract
Infrared thermal imaging of brain temperature changes is useful for evaluating cortical activity and disease states, such as stroke. However, the changes depend on a balance between changes in heat generation from metabolism and in heat convection related to blood flow. To discriminate between these effects and gain a clearer understanding of neurovascular metabolic coupling, brain temperature imaging must be improved to measure temperature and blood flow simultaneously. We develop an imaging technique that shows a two-dimensional (2-D) distribution of absolute brain temperature and relative cerebral blood flow changes in anesthetized rats by combining infrared thermal imaging with laser speckle imaging. The changes in brain metabolism and cerebral blood flow are achieved using two different anesthetics (isoflurane and α-chloralose) to evaluate our system. Isoflurane increased cerebral blood flow but decreased metabolism, whereas α-chloralose decreased both parameters. This technique enables simultaneous visualization of brain surface changes in temperature and cerebral blood flow in the same regions. This imaging system will permit further study of neurovascular metabolic coupling in normal and diseased brains.
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Affiliation(s)
- Takashi Suzuki
- Kyoto University, Research and Educational Unit of Leaders for Integrated Medical System, Center for the Promotion of Interdisciplinary Education and Research, Kyoto, Japan
| | - Naoya Oishi
- Kyoto University, Research and Educational Unit of Leaders for Integrated Medical System, Center for the Promotion of Interdisciplinary Education and Research, Kyoto, Japan
| | - Hidenao Fukuyama
- Kyoto University, Research and Educational Unit of Leaders for Integrated Medical System, Center for the Promotion of Interdisciplinary Education and Research, Kyoto, Japan
- Beijing Institute of Technology, Human Brain Research Laboratory, Intelligent Robotics Institute, Beijing, China
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Yaseen MA, Srinivasan VJ, Gorczynska I, Fujimoto JG, Boas DA, Sakadžić S. Multimodal optical imaging system for in vivo investigation of cerebral oxygen delivery and energy metabolism. BIOMEDICAL OPTICS EXPRESS 2015; 6:4994-5007. [PMID: 26713212 PMCID: PMC4679272 DOI: 10.1364/boe.6.004994] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 11/09/2015] [Accepted: 11/14/2015] [Indexed: 05/09/2023]
Abstract
Improving our understanding of brain function requires novel tools to observe multiple physiological parameters with high resolution in vivo. We have developed a multimodal imaging system for investigating multiple facets of cerebral blood flow and metabolism in small animals. The system was custom designed and features multiple optical imaging capabilities, including 2-photon and confocal lifetime microscopy, optical coherence tomography, laser speckle imaging, and optical intrinsic signal imaging. Here, we provide details of the system's design and present in vivo observations of multiple metrics of cerebral oxygen delivery and energy metabolism, including oxygen partial pressure, microvascular blood flow, and NADH autofluorescence.
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Affiliation(s)
- Mohammad A. Yaseen
- Department of Radiology, MGH/MIT/HMS Athinuola A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts,
USA
| | - Vivek J. Srinivasan
- Department of Radiology, MGH/MIT/HMS Athinuola A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts,
USA
- Current Affiliation: Department of Biomedical Engineering, University of California, Davis, Davis, California,
USA
| | - Iwona Gorczynska
- Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts,
USA
- Current Affiliation: Department of Biophysics and Medical Physics, Institute of Physics, Nicolaus Copernicus University, Torun,
Poland
| | - James G. Fujimoto
- Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts,
USA
| | - David A. Boas
- Department of Radiology, MGH/MIT/HMS Athinuola A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts,
USA
| | - Sava Sakadžić
- Department of Radiology, MGH/MIT/HMS Athinuola A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts,
USA
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Yaseen MA, Srinivasan VJ, Sakadžić S, Radhakrishnan H, Gorczynska I, Wu W, Fujimoto JG, Boas DA. Microvascular oxygen tension and flow measurements in rodent cerebral cortex during baseline conditions and functional activation. J Cereb Blood Flow Metab 2011; 31:1051-63. [PMID: 21179069 PMCID: PMC3070982 DOI: 10.1038/jcbfm.2010.227] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Revised: 11/17/2010] [Accepted: 11/26/2010] [Indexed: 12/13/2022]
Abstract
Measuring cerebral oxygen delivery and metabolism microscopically is important for interpreting macroscopic functional magnetic resonance imaging (fMRI) data and identifying pathological changes associated with stroke, Alzheimer's disease, and brain injury. Here, we present simultaneous, microscopic measurements of cerebral blood flow (CBF) and oxygen partial pressure (pO(2)) in cortical microvessels of anesthetized rats under baseline conditions and during somatosensory stimulation. Using a custom-built imaging system, we measured CBF with Fourier-domain optical coherence tomography (OCT), and vascular pO(2) with confocal phosphorescence lifetime microscopy. Cerebral blood flow and pO(2) measurements displayed heterogeneity over distances irresolvable with fMRI and positron emission tomography. Baseline measurements indicate O(2) extraction from pial arterioles and homogeneity of ascending venule pO(2) despite large variation in microvessel flows. Oxygen extraction is linearly related to flow in ascending venules, suggesting that flow in ascending venules closely matches oxygen demand of the drained territory. Oxygen partial pressure and relative CBF transients during somatosensory stimulation further indicate arteriolar O(2) extraction and suggest that arterioles contribute to the fMRI blood oxygen level dependent response. Understanding O(2) supply on a microscopic level will yield better insight into brain function and the underlying mechanisms of various neuropathologies.
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Affiliation(s)
- Mohammad A Yaseen
- Department of Radiology, MGH/MIT/HMS Athinuola A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Vivek J Srinivasan
- Department of Radiology, MGH/MIT/HMS Athinuola A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Sava Sakadžić
- Department of Radiology, MGH/MIT/HMS Athinuola A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Harsha Radhakrishnan
- Department of Radiology, MGH/MIT/HMS Athinuola A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Iwona Gorczynska
- Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Weicheng Wu
- Department of Radiology, MGH/MIT/HMS Athinuola A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - James G Fujimoto
- Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - David A Boas
- Department of Radiology, MGH/MIT/HMS Athinuola A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
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Bruyns-Haylett M, Zheng Y, Berwick J, Jones M. Temporal coupling between stimulus-evoked neural activity and hemodynamic responses from individual cortical columns. Phys Med Biol 2010; 55:2203-19. [DOI: 10.1088/0031-9155/55/8/006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Zheng Y, Pan Y, Harris S, Billings S, Coca D, Berwick J, Jones M, Kennerley A, Johnston D, Martin C, Devonshire IM, Mayhew J. A dynamic model of neurovascular coupling: implications for blood vessel dilation and constriction. Neuroimage 2010; 52:1135-47. [PMID: 20138217 DOI: 10.1016/j.neuroimage.2010.01.102] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2009] [Revised: 01/27/2010] [Accepted: 01/28/2010] [Indexed: 11/28/2022] Open
Abstract
Neurovascular coupling in response to stimulation of the rat barrel cortex was investigated using concurrent multichannel electrophysiology and laser Doppler flowmetry. The data were used to build a linear dynamic model relating neural activity to blood flow. Local field potential time series were subject to current source density analysis, and the time series of a layer IV sink of the barrel cortex was used as the input to the model. The model output was the time series of the changes in regional cerebral blood flow (CBF). We show that this model can provide excellent fit of the CBF responses for stimulus durations of up to 16 s. The structure of the model consisted of two coupled components representing vascular dilation and constriction. The complex temporal characteristics of the CBF time series were reproduced by the relatively simple balance of these two components. We show that the impulse response obtained under the 16-s duration stimulation condition generalised to provide a good prediction to the data from the shorter duration stimulation conditions. Furthermore, by optimising three out of the total of nine model parameters, the variability in the data can be well accounted for over a wide range of stimulus conditions. By establishing linearity, classic system analysis methods can be used to generate and explore a range of equivalent model structures (e.g., feed-forward or feedback) to guide the experimental investigation of the control of vascular dilation and constriction following stimulation.
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Affiliation(s)
- Ying Zheng
- Centre for Signal Processing in Neuro-imaging and Systems Neuroscience, Department of Psychology, University of Sheffield, Northumberland Road, Sheffield S10 2TP, UK.
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Almendros I, Montserrat JM, Torres M, González C, Navajas D, Farré R. Changes in oxygen partial pressure of brain tissue in an animal model of obstructive apnea. Respir Res 2010; 11:3. [PMID: 20078851 PMCID: PMC2817656 DOI: 10.1186/1465-9921-11-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2009] [Accepted: 01/15/2010] [Indexed: 12/03/2022] Open
Abstract
Background Cognitive impairment is one of the main consequences of obstructive sleep apnea (OSA) and is usually attributed in part to the oxidative stress caused by intermittent hypoxia in cerebral tissues. The presence of oxygen-reactive species in the brain tissue should be produced by the deoxygenation-reoxygenation cycles which occur at tissue level during recurrent apneic events. However, how changes in arterial blood oxygen saturation (SpO2) during repetitive apneas translate into oxygen partial pressure (PtO2) in brain tissue has not been studied. The objective of this study was to assess whether brain tissue is partially protected from intermittently occurring interruption of O2 supply during recurrent swings in arterial SpO2 in an animal model of OSA. Methods Twenty-four male Sprague-Dawley rats (300-350 g) were used. Sixteen rats were anesthetized and non-invasively subjected to recurrent obstructive apneas: 60 apneas/h, 15 s each, for 1 h. A control group of 8 rats was instrumented but not subjected to obstructive apneas. PtO2 in the cerebral cortex was measured using a fast-response oxygen microelectrode. SpO2 was measured by pulse oximetry. The time dependence of arterial SpO2 and brain tissue PtO2 was carried out by Friedman repeated measures ANOVA. Results Arterial SpO2 showed a stable periodic pattern (no significant changes in maximum [95.5 ± 0.5%; m ± SE] and minimum values [83.9 ± 1.3%]). By contrast, brain tissue PtO2 exhibited a different pattern from that of arterial SpO2. The minimum cerebral cortex PtO2 computed during the first apnea (29.6 ± 2.4 mmHg) was significantly lower than baseline PtO2 (39.7 ± 2.9 mmHg; p = 0.011). In contrast to SpO2, the minimum and maximum values of PtO2 gradually increased (p < 0.001) over the course of the 60 min studied. After 60 min, the maximum (51.9 ± 3.9 mmHg) and minimum (43.7 ± 3.8 mmHg) values of PtO2 were significantly greater relative to baseline and the first apnea dip, respectively. Conclusions These data suggest that the cerebral cortex is partially protected from intermittently occurring interruption of O2 supply induced by obstructive apneas mimicking OSA.
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