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Xie J, Li H, Su S, Cheng J, Cai Q, Tan H, Zu L, Qu X, Han H. Quantitative analysis of molecular transport in the extracellular space using physics-informed neural network. Comput Biol Med 2024; 171:108133. [PMID: 38364661 DOI: 10.1016/j.compbiomed.2024.108133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 02/06/2024] [Accepted: 02/12/2024] [Indexed: 02/18/2024]
Abstract
The brain extracellular space (ECS), an irregular, extremely tortuous nanoscale space located between cells or between cells and blood vessels, is crucial for nerve cell survival. It plays a pivotal role in high-level brain functions such as memory, emotion, and sensation. However, the specific form of molecular transport within the ECS remain elusive. To address this challenge, this paper proposes a novel approach to quantitatively analyze the molecular transport within the ECS by solving an inverse problem derived from the advection-diffusion equation (ADE) using a physics-informed neural network (PINN). PINN provides a streamlined solution to the ADE without the need for intricate mathematical formulations or grid settings. Additionally, the optimization of PINN facilitates the automatic computation of the diffusion coefficient governing long-term molecule transport and the velocity of molecules driven by advection. Consequently, the proposed method allows for the quantitative analysis and identification of the specific pattern of molecular transport within the ECS through the calculation of the Péclet number. Experimental validation on two datasets of magnetic resonance images (MRIs) captured at different time points showcases the effectiveness of the proposed method. Notably, our simulations reveal identical molecular transport patterns between datasets representing rats with tracer injected into the same brain region. These findings highlight the potential of PINN as a promising tool for comprehensively exploring molecular transport within the ECS.
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Affiliation(s)
- Jiayi Xie
- Department of Automation, Tsinghua University, Beijing 100084, China; Institute of Medical Technology, Peking University Health Science Center, Beijing 100191, China
| | - Hongfeng Li
- Institute of Medical Technology, Peking University Health Science Center, Beijing 100191, China
| | - Shaoyi Su
- Institute of Medical Technology, Peking University Health Science Center, Beijing 100191, China
| | - Jin Cheng
- School of Mathematical Sciences, Fudan University, Shanghai 200433, China
| | - Qingrui Cai
- National Integrated Circuit Industry Education Integration Innovation Platform, School of Electronic Science and Engineering (National Model Microelectronics College), Xiamen University, Xiamen 361102, China; Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, Xiamen University, Xiamen 361102, China
| | - Hanbo Tan
- Institute of Medical Technology, Peking University Health Science Center, Beijing 100191, China
| | - Lingyun Zu
- Department of Endocrinology and Metabolism, Department of Cardiology and Institute of Vascular Medicine, Peking University Third Hospital, Beijing 100191, China
| | - Xiaobo Qu
- National Integrated Circuit Industry Education Integration Innovation Platform, School of Electronic Science and Engineering (National Model Microelectronics College), Xiamen University, Xiamen 361102, China; Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, Xiamen University, Xiamen 361102, China
| | - Hongbin Han
- Institute of Medical Technology, Peking University Health Science Center, Beijing 100191, China; Department of Radiology, Peking University Third Hospital, Beijing 100191, China; Peking University Third Hospital, Beijing Key Laboratory of Magnetic Resonance Imaging Devices and Technology, Beijing 100191, China; NMPA key Laboratory of Evaluation of Medical Imaging Equipment and Technique, Beijing 100191, China.
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Abulikemu N, Gao X, Wang W, He Q, Wang G, Jiang T, Wang X, Cheng Y, Chen M, Li Y, Liu L, Zhao J, Li J, Jiang C, Wang Y, Han H, Wang J. Mechanism of extracellular space changes in cryptococcal brain granuloma revealed by MRI tracer. Front Neurosci 2022; 16:1034091. [PMID: 36605557 PMCID: PMC9808069 DOI: 10.3389/fnins.2022.1034091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 11/24/2022] [Indexed: 12/24/2022] Open
Abstract
Purpose This study aimed to investigate the changes in extracellular space (ECS) in cryptococcal brain granuloma and its pathological mechanism. Materials and methods The animal model of cryptococcal brain granuloma was established by injecting 1 × 106 CFU/ml of Cryptococcus neoformans type A suspension into the caudate nucleus of Sprague-Dawley rats with stereotactic technology. The infection in the brain was observed by conventional MRI scanning on days 14, 21, and 28 of modeling. The tracer-based MRI with a gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) as a magnetic tracer was performed on the rats with cryptococcal granuloma and the rats in the control group. The parameters of ECS in each area of cryptococcal brain granuloma were measured. The parameters of ECS in the two groups were compared by independent sample t-test, and the changes in ECS and its mechanism were analyzed. Results Up to 28 days of modeling, the success rate of establishing the brain cryptococcal granuloma model with 1 × 106 CFU/ml Cryptococcus neoformans suspension was 60%. In the internal area of cryptococcal granuloma, the effective diffusion coefficient D* was significantly higher than that of the control group (t = 2.76, P < 0.05), and the same trend showed in the volume ratio α (t = 3.71, P < 0.05), the clearance rate constant k (t = 3.137, P < 0.05), and the tracer half-life T1/2 (t = 3.837, P < 0.05). The tortuosity λ decreased compared with the control group (t = -2.70, P < 0.05). At the edge of the cryptococcal granuloma, the D* and α decreased, while the λ increased compared with the control group (D*:t = -6.05, P < 0.05; α: t = -4.988, P < 0.05; λ: t = 6.222, P < 0.05). Conclusion The internal area of the lesion demonstrated a quicker, broader, and more extended distribution of the tracer, while the edge of the lesion exhibited a slower and narrower distribution. MRI tracer method can monitor morphological and functional changes of ECS in pathological conditions and provide a theoretical basis for the treatment via ECS.
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Affiliation(s)
- Nuerbiyemu Abulikemu
- Imaging Center, First Affiliated Hospital of Xinjiang Medical University, Ürümqi, China,Beijing Key Laboratory of Magnetic Resonance Imaging Devices and Technology, Peking University Third Hospital, Beijing, China,Institute of Medical Technology, Peking University Health Science Center, Beijing, China
| | - Xin Gao
- Shanghai Universal Medical Imaging Diagnostic Center, Shanghai University, Shanghai, China
| | - Wei Wang
- Department of Rehabilitation Radiology, Beijing Rehabilitation Hospital, Capital Medical University, Beijing, China
| | - Qingyuan He
- Beijing Key Laboratory of Magnetic Resonance Imaging Devices and Technology, Peking University Third Hospital, Beijing, China,Institute of Medical Technology, Peking University Health Science Center, Beijing, China,Department of Radiology, Peking University Third Hospital, Beijing, China
| | - Gang Wang
- Imaging Center, First Affiliated Hospital of Xinjiang Medical University, Ürümqi, China,Imaging Center, Xi’an Gem Flower Changqing Hospital, Xi’an, China
| | - Tao Jiang
- The Animal Experimental Center, Xinjiang Medical University, Ürümqi, China
| | - Xiaodong Wang
- Department of Dermatology, First Affiliated Hospital of Xinjiang Medical University, Ürümqi, China
| | - Yumeng Cheng
- Beijing Key Laboratory of Magnetic Resonance Imaging Devices and Technology, Peking University Third Hospital, Beijing, China,Institute of Medical Technology, Peking University Health Science Center, Beijing, China
| | - Min Chen
- Department of Dermatology, Shanghai Key Laboratory of Molecular Medical Mycology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Yanran Li
- Imaging Center, First Affiliated Hospital of Xinjiang Medical University, Ürümqi, China
| | - Lulu Liu
- Imaging Center, First Affiliated Hospital of Xinjiang Medical University, Ürümqi, China
| | - Jingjing Zhao
- Imaging Center, First Affiliated Hospital of Xinjiang Medical University, Ürümqi, China
| | - Jin Li
- Imaging Center, First Affiliated Hospital of Xinjiang Medical University, Ürümqi, China
| | - Chunhui Jiang
- Imaging Center, First Affiliated Hospital of Xinjiang Medical University, Ürümqi, China
| | - Yunling Wang
- Imaging Center, First Affiliated Hospital of Xinjiang Medical University, Ürümqi, China
| | - Hongbin Han
- Beijing Key Laboratory of Magnetic Resonance Imaging Devices and Technology, Peking University Third Hospital, Beijing, China,Institute of Medical Technology, Peking University Health Science Center, Beijing, China,Department of Radiology, Peking University Third Hospital, Beijing, China,Hongbin Han,
| | - Jian Wang
- Imaging Center, First Affiliated Hospital of Xinjiang Medical University, Ürümqi, China,Shanghai Universal Medical Imaging Diagnostic Center, Shanghai University, Shanghai, China,*Correspondence: Jian Wang,
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Gao Y, Han H, Du J, He Q, Jia Y, Yan J, Dai H, Cui B, Yang J, Wei X, Yang L, Wang R, Long R, Ren Q, Yang X, Lu J. Early changes to the extracellular space in the hippocampus under simulated microgravity conditions. SCIENCE CHINA-LIFE SCIENCES 2021; 65:604-617. [PMID: 34185240 DOI: 10.1007/s11427-021-1932-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 05/26/2021] [Indexed: 01/11/2023]
Abstract
The smooth transportation of substances through the brain extracellular space (ECS) is crucial to maintaining brain function; however, the way this occurs under simulated microgravity remains unclear. In this study, tracer-based magnetic resonance imaging (MRI) and DECS-mapping techniques were used to image the drainage of brain interstitial fluid (ISF) from the ECS of the hippocampus in a tail-suspended hindlimb-unloading rat model at day 3 (HU-3) and 7 (HU-7). The results indicated that drainage of the ISF was accelerated in the HU-3 group but slowed markedly in the HU-7 group. The tortuosity of the ECS decreased in the HU-3 group but increased in the HU-7 group, while the volume fraction of the ECS increased in both groups. The diffusion rate within the ECS increased in the HU-3 group and decreased in the HU-7 group. The alterations to ISF drainage and diffusion in the ECS were recoverable in the HU-3 group, but neither parameter was restored in the HU-7 group. Our findings suggest that early changes to the hippocampal ECS and ISF drainage under simulated microgravity can be detected by tracer-based MRI, providing a new perspective for studying microgravity-induced nano-scale structure abnormities and developing neuroprotective approaches involving the brain ECS.
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Affiliation(s)
- Yajuan Gao
- Department of Radiology, Peking University Third Hospital, Beijing, 100191, China.,Institute of Medical Technology, Peking University Health Science Center, Beijing, 100191, China.,Beijing Key Laboratory of Magnetic Resonance Imaging Technology, Beijing, 100191, China
| | - Hongbin Han
- Department of Radiology, Peking University Third Hospital, Beijing, 100191, China. .,Institute of Medical Technology, Peking University Health Science Center, Beijing, 100191, China. .,Beijing Key Laboratory of Magnetic Resonance Imaging Technology, Beijing, 100191, China.
| | - Jichen Du
- Beijing Key Laboratory of Magnetic Resonance Imaging Technology, Beijing, 100191, China.,Department of Neurology, Aerospace Center Hospital, Peking University Aerospace Clinical College, Beijing, 100039, China
| | - Qingyuan He
- Department of Radiology, Peking University Third Hospital, Beijing, 100191, China.,Institute of Medical Technology, Peking University Health Science Center, Beijing, 100191, China.,Beijing Key Laboratory of Magnetic Resonance Imaging Technology, Beijing, 100191, China
| | - Yanxing Jia
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, 100191, China
| | - Junhao Yan
- Department of Anatomy and Histology, School of Basic Medical Sciences, Peking University, Beijing, 100191, China
| | - Hui Dai
- NHC Key Laboratory of Medical Immunology, Department of Immunology, School of Basic Medical Sciences, Peking University, Beijing, 100191, China
| | - Bin Cui
- Department of Radiology, Aerospace Center Hospital, Peking University Aerospace Clinical College, Beijing, 100039, China
| | - Jing Yang
- Department of Neurology, Aerospace Center Hospital, Peking University Aerospace Clinical College, Beijing, 100039, China
| | - Xunbin Wei
- Institute of Medical Technology, Peking University Health Science Center, Beijing, 100191, China
| | - Liu Yang
- Department of Radiology, Peking University Third Hospital, Beijing, 100191, China.,Institute of Medical Technology, Peking University Health Science Center, Beijing, 100191, China.,Beijing Key Laboratory of Magnetic Resonance Imaging Technology, Beijing, 100191, China
| | - Rui Wang
- Department of Radiology, Peking University Third Hospital, Beijing, 100191, China.,Institute of Medical Technology, Peking University Health Science Center, Beijing, 100191, China.,Beijing Key Laboratory of Magnetic Resonance Imaging Technology, Beijing, 100191, China
| | - Ren Long
- Department of Radiology, Peking University Third Hospital, Beijing, 100191, China.,Institute of Medical Technology, Peking University Health Science Center, Beijing, 100191, China.,Beijing Key Laboratory of Magnetic Resonance Imaging Technology, Beijing, 100191, China
| | - Qiushi Ren
- Institute of Medical Technology, Peking University Health Science Center, Beijing, 100191, China
| | - Xing Yang
- Institute of Medical Technology, Peking University Health Science Center, Beijing, 100191, China
| | - Jiabin Lu
- Department of Radiology, Peking University Third Hospital, Beijing, 100191, China.,Institute of Medical Technology, Peking University Health Science Center, Beijing, 100191, China.,Beijing Key Laboratory of Magnetic Resonance Imaging Technology, Beijing, 100191, China
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Li Y, Han H, Shi K, Cui D, Yang J, Alberts IL, Yuan L, Zhao G, Wang R, Cai X, Teng Z. The Mechanism of Downregulated Interstitial Fluid Drainage Following Neuronal Excitation. Aging Dis 2020; 11:1407-1422. [PMID: 33269097 PMCID: PMC7673848 DOI: 10.14336/ad.2020.0224] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 02/24/2020] [Indexed: 12/20/2022] Open
Abstract
The drainage of brain interstitial fluid (ISF) has been observed to slow down following neuronal excitation, although the mechanism underlying this phenomenon is yet to be elucidated. In searching for the changes in the brain extracellular space (ECS) induced by electrical pain stimuli in the rat thalamus, significantly decreased effective diffusion coefficient (DECS) and volume fraction (α) of the brain ECS were shown, accompanied by the slowdown of ISF drainage. The morphological basis for structural changes in the brain ECS was local spatial deformation of astrocyte foot processes following neuronal excitation. We further studied aquaporin-4 gene (APQ4) knockout rats in which the changes of the brain ECS structure were reversed and found that the slowed DECS and ISF drainage persisted, confirming that the down-regulation of ISF drainage following neuronal excitation was mainly attributable to the release of neurotransmitters rather than to structural changes of the brain ECS. Meanwhile, the dynamic changes in the DECS were synchronized with the release and elimination processes of neurotransmitters following neuronal excitation. In conclusion, the downregulation of ISF drainage following neuronal excitation was found to be caused by the restricted diffusion in the brain ECS, and DECS mapping may be used to track the neuronal activity in the deep brain.
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Affiliation(s)
- Yuanyuan Li
- Department of Radiology, Peking University Third Hospital, Beijing, China.
- Beijing Key Laboratory of Magnetic Resonance Imaging Equipment and Technique, Beijing, China.
| | - Hongbin Han
- Department of Radiology, Peking University Third Hospital, Beijing, China.
- Beijing Key Laboratory of Magnetic Resonance Imaging Equipment and Technique, Beijing, China.
- Institute of Medical Technology, Peking University Health Science Center, Beijing, China.
| | - Kuangyu Shi
- Department of Nuclear Medicine, University of Bern, 3010 Bern, Switzerland.
- Department of Informatics, Technical University of Munich, Garching 85748, Germany.
| | - Dehua Cui
- Beijing Key Laboratory of Magnetic Resonance Imaging Equipment and Technique, Beijing, China.
| | - Jun Yang
- Department of Radiology, Peking University Third Hospital, Beijing, China.
| | - Ian Leigh Alberts
- Department of Nuclear Medicine, University of Bern, 3010 Bern, Switzerland.
| | - Lan Yuan
- Peking University Medical and Health Analysis Center, Peking University Health Science Center, Beijing, China.
| | - Guomei Zhao
- Department of Radiology, Peking University Third Hospital, Beijing, China.
- Beijing Key Laboratory of Magnetic Resonance Imaging Equipment and Technique, Beijing, China.
| | - Rui Wang
- Department of Radiology, Peking University Third Hospital, Beijing, China.
- Beijing Key Laboratory of Magnetic Resonance Imaging Equipment and Technique, Beijing, China.
| | - Xianjie Cai
- Department of Radiology, Peking University Third Hospital, Beijing, China.
- Beijing Key Laboratory of Magnetic Resonance Imaging Equipment and Technique, Beijing, China.
| | - Ze Teng
- Department of Radiology, Cancer Hospital Chinese Academy of Medical Sciences, Beijing, China.
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