1
|
Abstract
The brain harbors a unique ability to, figuratively speaking, shift its gears. During wakefulness, the brain is geared fully toward processing information and behaving, while homeostatic functions predominate during sleep. The blood-brain barrier establishes a stable environment that is optimal for neuronal function, yet the barrier imposes a physiological problem; transcapillary filtration that forms extracellular fluid in other organs is reduced to a minimum in brain. Consequently, the brain depends on a special fluid [the cerebrospinal fluid (CSF)] that is flushed into brain along the unique perivascular spaces created by astrocytic vascular endfeet. We describe this pathway, coined the term glymphatic system, based on its dependency on astrocytic vascular endfeet and their adluminal expression of aquaporin-4 water channels facing toward CSF-filled perivascular spaces. Glymphatic clearance of potentially harmful metabolic or protein waste products, such as amyloid-β, is primarily active during sleep, when its physiological drivers, the cardiac cycle, respiration, and slow vasomotion, together efficiently propel CSF inflow along periarterial spaces. The brain's extracellular space contains an abundance of proteoglycans and hyaluronan, which provide a low-resistance hydraulic conduit that rapidly can expand and shrink during the sleep-wake cycle. We describe this unique fluid system of the brain, which meets the brain's requisites to maintain homeostasis similar to peripheral organs, considering the blood-brain-barrier and the paths for formation and egress of the CSF.
Collapse
Affiliation(s)
- Martin Kaag Rasmussen
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Humberto Mestre
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, New York
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, New York
| |
Collapse
|
2
|
Feng Y, Fu S, Li C, Ma X, Wu Y, Chen F, Li G, Liu M, Liu H, Zhu J, Lan Z, Jiang G. Interaction of Gut Microbiota and Brain Function in Patients With Chronic Insomnia: A Regional Homogeneity Study. Front Neurosci 2022; 15:804843. [PMID: 35069107 PMCID: PMC8766814 DOI: 10.3389/fnins.2021.804843] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 12/14/2021] [Indexed: 12/12/2022] Open
Abstract
Recent studies have shown that the human gut microbiota (GM) plays a critical role in brain function and behavior via the complex microbiome–gut–brain axis. However, knowledge about the underlying relationship between the GM and changes in brain function in patients with chronic insomnia (CI) is still very limited. In this prospective study, 31 CI patients and 30 healthy controls were recruited. Resting-state functional magnetic resonance imaging scans were performed and brain functional alterations in CI patients were evaluated using the regional homogeneity (ReHo) method. We collected fecal samples of CI patients and used 16S rDNA amplicon sequencing to assess the relative abundance (RA) and alpha diversity of the GM. We also performed extensive sleep, mood, and cognitive assessments. Then, we tested for potential associations between the GM profile, ReHo alterations, and neuropsychological changes in CI patients. Our results showed associations between the RA of Lactobacilli, ReHo values in the left fusiform gyrus, and depression scores in CI patients. We also found some bacterial genera related to ReHo values of the right triangular inferior frontal gyrus. In addition, the RA of genus Coprobacter was correlated with ReHo values of the left angular gyrus and with specific cognitive performance. These findings revealed complex relationships between GM, brain function, and behavior in patients with CI.
Collapse
Affiliation(s)
- Ying Feng
- The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China.,Department of Medical Imaging, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Shishun Fu
- Department of Medical Imaging, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Cheng Li
- Guangdong Traditional Medical and Sports Injury Rehabilitation Research Institute, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Xiaofen Ma
- Department of Medical Imaging, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Yunfan Wu
- Department of Medical Imaging, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Feng Chen
- Department of Medical Imaging, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Guomin Li
- Department of Medical Imaging, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Mengchen Liu
- Department of Medical Imaging, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Hang Liu
- Department of Medical Imaging, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Jiaying Zhu
- Department of Medical Imaging, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Zhihong Lan
- Department of Medical Imaging, Zhuhai People's Hospital, Zhuhai, China
| | - Guihua Jiang
- Department of Medical Imaging, Guangdong Second Provincial General Hospital, Guangzhou, China.,The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
| |
Collapse
|
3
|
Afrashteh N, Inayat S, Bermudez-Contreras E, Luczak A, McNaughton BL, Mohajerani MH. Spatiotemporal structure of sensory-evoked and spontaneous activity revealed by mesoscale imaging in anesthetized and awake mice. Cell Rep 2021; 37:110081. [PMID: 34879278 DOI: 10.1016/j.celrep.2021.110081] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 05/25/2021] [Accepted: 11/10/2021] [Indexed: 11/22/2022] Open
Abstract
Stimuli-evoked and spontaneous brain activity propagates across the cortex in diverse spatiotemporal patterns. Despite extensive studies, the relationship between spontaneous and evoked activity is poorly understood. We investigate this relationship by comparing the amplitude, speed, direction, and complexity of propagation trajectories of spontaneous and evoked activity elicited with visual, auditory, and tactile stimuli using mesoscale wide-field imaging in mice. For both spontaneous and evoked activity, the speed and direction of propagation is modulated by the amplitude. However, spontaneous activity has a higher complexity of the propagation trajectories. For low stimulus strengths, evoked activity amplitude and speed is similar to that of spontaneous activity but becomes dissimilar at higher stimulus strengths. These findings are consistent with observations that primary sensory areas receive widespread inputs from other cortical regions, and during rest, the cortex tends to reactivate traces of complex multisensory experiences that might have occurred in exhibition of different behaviors.
Collapse
Affiliation(s)
- Navvab Afrashteh
- University of Lethbridge, Faculty of Arts and Sciences, Department of Neuroscience, 4401 University Dr. W., Lethbridge, Alberta T1K 3M4, Canada
| | - Samsoon Inayat
- University of Lethbridge, Faculty of Arts and Sciences, Department of Neuroscience, 4401 University Dr. W., Lethbridge, Alberta T1K 3M4, Canada
| | - Edgar Bermudez-Contreras
- University of Lethbridge, Faculty of Arts and Sciences, Department of Neuroscience, 4401 University Dr. W., Lethbridge, Alberta T1K 3M4, Canada
| | - Artur Luczak
- University of Lethbridge, Faculty of Arts and Sciences, Department of Neuroscience, 4401 University Dr. W., Lethbridge, Alberta T1K 3M4, Canada
| | - Bruce L McNaughton
- University of Lethbridge, Faculty of Arts and Sciences, Department of Neuroscience, 4401 University Dr. W., Lethbridge, Alberta T1K 3M4, Canada; Center for Neurobiology of Learning and Memory, Department of Neurobiology and Behavior, University of California, Irvine, CA 92603, USA
| | - Majid H Mohajerani
- University of Lethbridge, Faculty of Arts and Sciences, Department of Neuroscience, 4401 University Dr. W., Lethbridge, Alberta T1K 3M4, Canada.
| |
Collapse
|
4
|
A study of regional homogeneity of resting-state Functional Magnetic Resonance Imaging in mild cognitive impairment. Behav Brain Res 2021; 402:113103. [PMID: 33417993 DOI: 10.1016/j.bbr.2020.113103] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 12/21/2020] [Accepted: 12/27/2020] [Indexed: 11/23/2022]
Abstract
Mild cognitive impairment (MCI) is considered to be the early stage of Alzheimer's disease (AD), but the diagnostic predictive markers for MCI patients are still unclear. Here we have identified the brain function activity changes in MCI patients by using the resting-state functional magnetic resonance imaging (rs-fMRI). A total of 28 MCI patients and 38 age- and gender-matched healthy controls from the Wuxi Mental Health Center were recruited, and their abnormal spontaneous brain activities in the MCI were examined. The results showed that, compared with the healthy controls, MCI patients exhibited reduced regional homogeneity (ReHo) in the right superior temporal gyrus, right middle temporal gyrus, left angular gyrus and superior marginal gyrus. In addition, the correlation analysis revealed that ReHo in these regions were not correlated with the AD Assessment Scale-Cognitive score in MCI. We concluded abnormalities in the right superior temporal gyrus, right middle temporal gyrus, left angular gyrus and superior marginal gyrus with MCI, suggesting that the right language network may be impaired in MCI, which may provide a better understanding of dementia progression and potentially comprehensive treatment in MCI.
Collapse
|
5
|
Huotari N, Raitamaa L, Helakari H, Kananen J, Raatikainen V, Rasila A, Tuovinen T, Kantola J, Borchardt V, Kiviniemi VJ, Korhonen VO. Sampling Rate Effects on Resting State fMRI Metrics. Front Neurosci 2019; 13:279. [PMID: 31001071 PMCID: PMC6454039 DOI: 10.3389/fnins.2019.00279] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 03/08/2019] [Indexed: 01/21/2023] Open
Abstract
Low image sampling rates used in resting state functional magnetic resonance imaging (rs-fMRI) may cause aliasing of the cardiorespiratory pulsations over the very low frequency (VLF) BOLD signal fluctuations which reflects to functional connectivity (FC). In this study, we examine the effect of sampling rate on currently used rs-fMRI FC metrics. Ultra-fast fMRI magnetic resonance encephalography (MREG) data, sampled with TR 0.1 s, was downsampled to different subsampled repetition times (sTR, range 0.3–3 s) for comparisons. Echo planar k-space sampling (TR 2.15 s) and interleaved slice collection schemes were also compared against the 3D single shot trajectory at 2.2 s sTR. The quantified connectivity metrics included stationary spatial, time, and frequency domains, as well as dynamic analyses. Time domain methods included analyses of seed-based functional connectivity, regional homogeneity (ReHo), coefficient of variation, and spatial domain group level probabilistic independent component analysis (ICA). In frequency domain analyses, we examined fractional and amplitude of low frequency fluctuations. Aliasing effects were spatially and spectrally analyzed by comparing VLF (0.01–0.1 Hz), respiratory (0.12–0.35 Hz) and cardiac power (0.9–1.3 Hz) FFT maps at different sTRs. Quasi-periodic pattern (QPP) of VLF events were analyzed for effects on dynamic FC methods. The results in conventional time and spatial domain analyses remained virtually unchanged by the different sampling rates. In frequency domain, the aliasing occurred mainly in higher sTR (1–2 s) where cardiac power aliases over respiratory power. The VLF power maps suffered minimally from increasing sTRs. Interleaved data reconstruction induced lower ReHo compared to 3D sampling (p < 0.001). Gradient recalled echo-planar imaging (EPI BOLD) data produced both better and worse metrics. In QPP analyses, the repeatability of the VLF pulse detection becomes linearly reduced with increasing sTR. In conclusion, the conventional resting state metrics (e.g., FC, ICA) were not markedly affected by different TRs (0.1–3 s). However, cardiorespiratory signals showed strongest aliasing in central brain regions in sTR 1–2 s. Pulsatile QPP and other dynamic analyses benefit linearly from short TR scanning.
Collapse
Affiliation(s)
- Niko Huotari
- Oulu Functional NeuroImaging Group, Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland.,Department of Diagnostic Radiology, Medical Research Center, Oulu University Hospital, Oulu, Finland
| | - Lauri Raitamaa
- Oulu Functional NeuroImaging Group, Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland.,Department of Diagnostic Radiology, Medical Research Center, Oulu University Hospital, Oulu, Finland
| | - Heta Helakari
- Oulu Functional NeuroImaging Group, Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland.,Department of Diagnostic Radiology, Medical Research Center, Oulu University Hospital, Oulu, Finland
| | - Janne Kananen
- Oulu Functional NeuroImaging Group, Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland.,Department of Diagnostic Radiology, Medical Research Center, Oulu University Hospital, Oulu, Finland
| | - Ville Raatikainen
- Oulu Functional NeuroImaging Group, Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland.,Department of Diagnostic Radiology, Medical Research Center, Oulu University Hospital, Oulu, Finland
| | - Aleksi Rasila
- Oulu Functional NeuroImaging Group, Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland.,Department of Diagnostic Radiology, Medical Research Center, Oulu University Hospital, Oulu, Finland
| | - Timo Tuovinen
- Oulu Functional NeuroImaging Group, Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland.,Department of Diagnostic Radiology, Medical Research Center, Oulu University Hospital, Oulu, Finland
| | - Jussi Kantola
- Oulu Functional NeuroImaging Group, Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland.,Department of Diagnostic Radiology, Medical Research Center, Oulu University Hospital, Oulu, Finland
| | - Viola Borchardt
- Oulu Functional NeuroImaging Group, Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland.,Department of Diagnostic Radiology, Medical Research Center, Oulu University Hospital, Oulu, Finland
| | - Vesa J Kiviniemi
- Oulu Functional NeuroImaging Group, Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland.,Department of Diagnostic Radiology, Medical Research Center, Oulu University Hospital, Oulu, Finland
| | - Vesa O Korhonen
- Oulu Functional NeuroImaging Group, Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland.,Department of Diagnostic Radiology, Medical Research Center, Oulu University Hospital, Oulu, Finland
| |
Collapse
|
6
|
Pang R, Guo R, Wu X, Hu F, Liu M, Zhang L, Wang Z, Li K. Altered Regional Homogeneity in Chronic Insomnia Disorder with or without Cognitive Impairment. AJNR Am J Neuroradiol 2018; 39:742-747. [PMID: 29496724 DOI: 10.3174/ajnr.a5587] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 12/29/2017] [Indexed: 01/05/2023]
Abstract
BACKGROUND AND PURPOSE Many studies have shown that insomnia is an independent factor in cognitive impairment, but the involved neurobiological mechanisms remain unclear. We used regional homogeneity to explore the specific neurobiologic indicators of chronic insomnia disorder with mild cognitive impairment. MATERIALS AND METHODS Thirty-nine patients with insomnia were divided into a group with and without cognitive impairment; we also included a control group (n = 28). Abnormalities in brain functional activity were identified by comparing the regional homogeneity values for each brain region among the groups. RESULTS Subjective insomnia scores were negatively correlated with cognitive impairment after controlling for age, sex, and educational effects. Regions with significant differences in regional homogeneity values in the 3 groups were concentrated in the right medial prefrontal cortex, the right superior frontal gyrus, and the left superior occipital gyrus. Meanwhile, subjective insomnia scores were negatively correlated with the strength of the decreased regional homogeneity in the right medial prefrontal cortex. The increased regional homogeneity value in the right superior frontal gyrus was positively correlated with the Montreal Cognitive Assessment score in patients. CONCLUSIONS Our results indicate that decreased regional homogeneity values in the medial prefrontal cortex and increased regional homogeneity values in the cuneus may be important neurobiologic indicators of chronic insomnia disorder and accompanying cognitive impairment. Overall, our study described the regional homogeneity of the whole brain in chronic insomnia disorder with mild cognitive impairment and could be the basis for future studies.
Collapse
Affiliation(s)
- R Pang
- From the Departments of Radiology (R.P., M.L., Z.W., K.L.).,Department of Radiology (R.P., K.L.), Xuanwu Hospital, Capital Medical University, Beijing, China
| | | | - X Wu
- Acupuncture (X.W.), Dongfang Hospital, Beijing University of Chinese Medicine, Beijing, China
| | - F Hu
- Institute of Automation (F.H.), Chinese Academy of Sciences. Beijing, China.,School of Automation (F.H.), Harbin University of Science and Technology, Harbin, China
| | - M Liu
- From the Departments of Radiology (R.P., M.L., Z.W., K.L.)
| | | | - Z Wang
- From the Departments of Radiology (R.P., M.L., Z.W., K.L.)
| | - K Li
- From the Departments of Radiology (R.P., M.L., Z.W., K.L.) .,Department of Radiology (R.P., K.L.), Xuanwu Hospital, Capital Medical University, Beijing, China.,Beijing Key Laboratory of Magnetic Resonance Imaging and Brain Informatics (K.L.), Beijing, China
| |
Collapse
|
7
|
Kiviniemi V, Wang X, Korhonen V, Keinänen T, Tuovinen T, Autio J, LeVan P, Keilholz S, Zang YF, Hennig J, Nedergaard M. Ultra-fast magnetic resonance encephalography of physiological brain activity - Glymphatic pulsation mechanisms? J Cereb Blood Flow Metab 2016; 36:1033-45. [PMID: 26690495 PMCID: PMC4908626 DOI: 10.1177/0271678x15622047] [Citation(s) in RCA: 225] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 11/06/2015] [Indexed: 11/16/2022]
Abstract
The theory on the glymphatic convection mechanism of cerebrospinal fluid holds that cardiac pulsations in part pump cerebrospinal fluid from the peri-arterial spaces through the extracellular tissue into the peri-venous spaces facilitated by aquaporin water channels. Since cardiac pulses cannot be the sole mechanism of glymphatic propulsion, we searched for additional cerebrospinal fluid pulsations in the human brain with ultra-fast magnetic resonance encephalography. We detected three types of physiological mechanisms affecting cerebral cerebrospinal fluid pulsations: cardiac, respiratory, and very low frequency pulsations. The cardiac pulsations induce a negative magnetic resonance encephalography signal change in peri-arterial regions that extends centrifugally and covers the brain in ≈1 Hz cycles. The respiratory ≈0.3 Hz pulsations are centripetal periodical pulses that occur dominantly in peri-venous areas. The third type of pulsation was very low frequency (VLF 0.001-0.023 Hz) and low frequency (LF 0.023-0.73 Hz) waves that both propagate with unique spatiotemporal patterns. Our findings using critically sampled magnetic resonance encephalography open a new view into cerebral fluid dynamics. Since glymphatic system failure may precede protein accumulations in diseases such as Alzheimer's dementia, this methodological advance offers a novel approach to image brain fluid dynamics that potentially can enable early detection and intervention in neurodegenerative diseases.
Collapse
Affiliation(s)
- Vesa Kiviniemi
- Oulu Functional NeuroImaging, Department of Diagnostic Radiology, MRC, Oulu University Hospital, Oulu, Finland Medical Imaging, Physics and Technology, the Faculty of Medicine, University of Oulu, Oulu, Finland
| | - Xindi Wang
- Oulu Functional NeuroImaging, Department of Diagnostic Radiology, MRC, Oulu University Hospital, Oulu, Finland Medical Imaging, Physics and Technology, the Faculty of Medicine, University of Oulu, Oulu, Finland State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, China
| | - Vesa Korhonen
- Oulu Functional NeuroImaging, Department of Diagnostic Radiology, MRC, Oulu University Hospital, Oulu, Finland Medical Imaging, Physics and Technology, the Faculty of Medicine, University of Oulu, Oulu, Finland
| | - Tuija Keinänen
- Oulu Functional NeuroImaging, Department of Diagnostic Radiology, MRC, Oulu University Hospital, Oulu, Finland Medical Imaging, Physics and Technology, the Faculty of Medicine, University of Oulu, Oulu, Finland
| | - Timo Tuovinen
- Oulu Functional NeuroImaging, Department of Diagnostic Radiology, MRC, Oulu University Hospital, Oulu, Finland Medical Imaging, Physics and Technology, the Faculty of Medicine, University of Oulu, Oulu, Finland
| | - Joonas Autio
- Oulu Functional NeuroImaging, Department of Diagnostic Radiology, MRC, Oulu University Hospital, Oulu, Finland Functional Architecture Team, Center for Life Science Technologies, RIKEN, Japan
| | - Pierre LeVan
- Medical Physics, Department of Radiology, University Medical Center Freiburg, Freiburg, Germany
| | - Shella Keilholz
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University School of Medicine, Atlanta, GA, USA
| | - Yu-Feng Zang
- Center for Cognition and Brain Disorders, Hangzhou Normal University, Hangzhou, China
| | - Jürgen Hennig
- Medical Physics, Department of Radiology, University Medical Center Freiburg, Freiburg, Germany
| | - Maiken Nedergaard
- School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY, USA
| |
Collapse
|
8
|
Li Y, Yuan K, Bi Y, Guan Y, Cheng J, Zhang Y, Shi S, Lu X, Yu D, Tian J. Neural correlates of 12-h abstinence-induced craving in young adult smokers: a resting-state study. Brain Imaging Behav 2016; 11:677-684. [DOI: 10.1007/s11682-016-9544-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
|
9
|
Liu L, Wu Y, Zheng J, Lai X, Zeng D, Li H, Shi C, Yang M, Liang C. Cerebral activation effects of acupuncture using Zusanli (ST36) and Yanglingquan (GB34) points based on Regional Homogeneity indices: A resting-state fMRI study. JOURNAL OF X-RAY SCIENCE AND TECHNOLOGY 2016; 24:297-308. [PMID: 27002910 DOI: 10.3233/xst-160557] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
OBJECTIVE This study aimed to observe the cerebral activation effects of acupuncturing the Zusanli (ST36) plusYanglingquan (GB34) points in young healthy volunteers based on Regional Homogeneity (ReHo) indices. METHODS Ten healthy volunteers were enrolled, including 4 males and 6 females between the ages 20 and 34 years with a median age of 23 years. Magnetic resonance imaging (GE Signa HDxt 3.0T) was performed in four groups: Before acupuncture (Control Group), after acupuncture at Zusanli (ST36 Group), after acupuncture at Yanglingquan (GB34 Group) and after acupuncture at both Zusanli and Yanglingquan (Compatibility Group). Differences in the brain ReHo indices of the 4 groups were analyzed by statistical parametric mapping (SPM8) and ReHo data processing methods. The significantly different brain regions were obtained using a false discovery rate correction (FDR-Corrected). RESULTS The ReHo indices revealed that the main significant effect was in the Compatibility Group. Compared with the resting state of the Control Group, the ReHo values of the Compatibility Group increased in the right middle frontal gyrus (BA8, 9), left superior temporal areas (BA22), ventral anterior cingulate area (BA24) and right inferior parietal lobe (BA40); in contrast, the ReHo values decreased in the left thalamus, right insular cortex (BA13), left inferior frontal lobe (BA9) and right dorsal anterior cingulate area (BA32). Our analysis showed that the Compatibility Group had higher ReHo values than the left inferior parietal lobule (BA40) and right frontal cortex (BA6) of the ST36 Group and the posterior lobe of the right cerebellum, dorsal anterior cingulate (BA32), left and right middle frontal gyrus (BA46, BA9), left precuneus (BA7), right inferior parietal love (BA40) of the GB34 Group. CONCLUSION The results of our neuroimaging study suggest that the combination of acupoints could more widely activate areas of the brain compared to a single acupoint. Additionally, the combination of acupoints can activate some new brain areas and generate new curative effects.
Collapse
Affiliation(s)
- Liansheng Liu
- Southern Medical University, Guangzhou, Guangdong, China
- Department of Radiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
- First Affiliated Hospital of Guangzhou University of TCM, Guangdong, China
| | - Yuefeng Wu
- Acupuncture and Moxibustion College of Guangzhou University of TCM, Guangdong, China
| | - Jiayi Zheng
- Acupuncture and Moxibustion College of Guangzhou University of TCM, Guangdong, China
| | - Xinsheng Lai
- Acupuncture and Moxibustion College of Guangzhou University of TCM, Guangdong, China
| | - Daohui Zeng
- First Affiliated Hospital of Guangzhou University of TCM, Guangdong, China
| | - Hengguo Li
- First Affiliated Hospital of Jinan University, Guangdong, China
| | - Changzheng Shi
- First Affiliated Hospital of Jinan University, Guangdong, China
| | - Minjie Yang
- First Affiliated Hospital of Jinan University, Guangdong, China
| | - Changhong Liang
- Southern Medical University, Guangzhou, Guangdong, China
- Department of Radiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| |
Collapse
|
10
|
Decreased Regional Homogeneity in Patients With Acute Mild Traumatic Brain Injury: A Resting-State fMRI Study. J Nerv Ment Dis 2015; 203:786-91. [PMID: 26348589 DOI: 10.1097/nmd.0000000000000368] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Mild traumatic brain injury (mTBI) is characterized by structural disconnection and large-scale neural network dysfunction in the resting state. However, little is known concerning the intrinsic changes in local spontaneous brain activity in patients with mTBI. The aim of the current study was to assess regional synchronization in acute mTBI patients. Fifteen acute mTBI patients and 15 sex-, age-, and education-matched healthy controls (HCs) were studied. We used the regional homogeneity (ReHo) method to map local connectivity across the whole brain and performed a two-sample t-test between the two groups. Compared with HCs, patients with acute mTBI showed significantly decreased ReHo in the left insula, left precentral/postcentral gyrus, and left supramarginal gyrus (p < 0.05, AlphaSim corrected). The ReHo index of the left insula showed a positive correlation with the Mini-Mental State Examination (MMSE) scores across all acute mTBI patients (p < 0.05, uncorrected). The ReHo method may provide an objective biomarker for evaluating the functional abnormity of mTBI in the acute setting.
Collapse
|
11
|
Wu G, Yang S, Zhu L, Lin F. Altered spontaneous brain activity in heavy smokers revealed by regional homogeneity. Psychopharmacology (Berl) 2015; 232:2481-9. [PMID: 25716308 DOI: 10.1007/s00213-015-3881-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 01/28/2015] [Indexed: 10/23/2022]
Abstract
RATIONALE Task-state and resting-state functional magnetic resonance imaging (fMRI) studies have revealed different brain responses in chronic cigarette smokers compared with healthy controls. However, little is known about the differences between chronic cigarette smokers and healthy subjects regarding the local synchronization of spontaneous brain activity in the resting state. OBJECTIVES In this study, we used regional homogeneity (ReHo) analysis based on resting-state fMRI to investigate intrinsic brain activity in heavy smokers. METHODS Thirty-one heavy smokers and 33 healthy non-smokers were included in this study. ReHo was used to measure spontaneous brain activity, and whole-brain voxel-wise comparisons of ReHo were performed to detect brain regions with altered spontaneous brain activity between groups. RESULTS Compared with non-smokers, heavy smokers showed decreased ReHo primarily in brain regions associated with the default-mode, frontoparietal attention, and inhibitory control networks; heavy smokers showed increased ReHo predominately in regions related to motor planning. CONCLUSIONS Our results suggest that heavy smokers may have altered spontaneous brain activity in some brain regions that are associated with higher cognitive networks. Moreover, our study improves the understanding of the effects of chronic cigarette smoking on spontaneous brain activity and the pathophysiological mechanisms of nicotine dependence.
Collapse
Affiliation(s)
- Guangyao Wu
- Department of Magnetic Resonance Imaging, Zhongnan Hospital of Wuhan University, Wuhan, 430071, People's Republic of China,
| | | | | | | |
Collapse
|
12
|
Using regional homogeneity to reveal altered spontaneous activity in patients with mild cognitive impairment. BIOMED RESEARCH INTERNATIONAL 2015; 2015:807093. [PMID: 25738156 PMCID: PMC4337114 DOI: 10.1155/2015/807093] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Revised: 01/13/2015] [Accepted: 01/13/2015] [Indexed: 01/08/2023]
Abstract
Most patients with mild cognitive impairment (MCI) are thought to be in an early stage of Alzheimer's disease (AD). Resting-state functional magnetic resonance imaging reflects spontaneous brain activity and/or the endogenous/background neurophysiological process of the human brain. Regional homogeneity (ReHo) rapidly maps regional brain activity across the whole brain. In the present study, we used the ReHo index to explore whole brain spontaneous activity pattern in MCI. Our results showed that MCI subjects displayed an increased ReHo index in the paracentral lobe, precuneus, and postcentral and a decreased ReHo index in the medial temporal gyrus and hippocampus. Impairments in the medial temporal gyrus and hippocampus may serve as important markers distinguishing MCI from healthy aging. Moreover, the increased ReHo index observed in the postcentral and paracentral lobes might indicate compensation for the cognitive function losses in individuals with MCI.
Collapse
|
13
|
Altered spontaneous activity in the default-mode network and cognitive decline in chronic subcortical stroke. J Neurol Sci 2014; 347:193-8. [DOI: 10.1016/j.jns.2014.08.049] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Revised: 07/09/2014] [Accepted: 08/21/2014] [Indexed: 11/24/2022]
|
14
|
Korhonen V, Hiltunen T, Myllylä T, Wang X, Kantola J, Nikkinen J, Zang YF, LeVan P, Kiviniemi V. Synchronous multiscale neuroimaging environment for critically sampled physiological analysis of brain function: hepta-scan concept. Brain Connect 2014; 4:677-89. [PMID: 25131996 DOI: 10.1089/brain.2014.0258] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Functional connectivity of the resting-state networks of the brain is thought to be mediated by very-low-frequency fluctuations (VLFFs <0.1 Hz) in neuronal activity. However, vasomotor waves and cardiorespiratory pulsations influence indirect measures of brain function, such as the functional magnetic resonance imaging blood-oxygen-level-dependent (BOLD) signal. How strongly physiological oscillations correlate with spontaneous BOLD signals is not known, partially due to differences in the data-sampling rates of different methods. Recent ultrafast inverse imaging sequences, including magnetic resonance encephalography (MREG), enable critical sampling of these signals. In this study, we describe a multimodal concept, referred to as Hepta-scan, which incorporates synchronous MREG with scalp electroencephalography, near-infrared spectroscopy, noninvasive blood pressure, and anesthesia monitoring. Our preliminary results support the idea that, in the absence of aliased cardiorespiratory signals, VLFFs in the BOLD signal are affected by vasomotor and electrophysiological sources. Further, MREG signals showed a high correlation coefficient between the ventromedial default mode network (DMNvmpf) and electrophysiological signals, especially in the VLF range. Also, oxy- and deoxyhemoglobin and vasomotor waves were found to correlate with DMNvmpf. Intriguingly, usage of shorter time windows in these correlation measurements produced significantly (p<0.05) higher positive and negative correlation coefficients, suggesting temporal nonstationary behavior between the measurements. Focus on the VLF range strongly increased correlation strength.
Collapse
Affiliation(s)
- Vesa Korhonen
- 1 Department of Diagnostic Radiology, Institute of Diagnostics , Medical Research Center of Oulu, Oulu, Finland
| | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Liu Z, Wei W, Bai L, Dai R, You Y, Chen S, Tian J. Exploring the patterns of acupuncture on mild cognitive impairment patients using regional homogeneity. PLoS One 2014; 9:e99335. [PMID: 24968124 PMCID: PMC4072601 DOI: 10.1371/journal.pone.0099335] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Accepted: 05/12/2014] [Indexed: 11/18/2022] Open
Abstract
PURPOSE To investigate the different responses to acupuncture in MCI patients and age-matched healthy subjects reflected by the Regional Homogeneity (ReHo) indices. METHODS The experiment was performed at the acupoint KI3 in 12 MCI patients and 12 healthy controls, respectively. A novel non-repeated event-related (NRER) fMRI design paradigm was applied to separately detect neural activities related to different stages of acupuncture (pre-acupuncture resting state, needling manipulation and post-acupuncture resting state). ReHo values were calculated for MCI patients and healthy controls in pre- and post-acupuncture resting state. Then, a two-way ANCOVA with repeated measures with post-hoc two sample t-tests was performed to explore the different responses to acupuncture in the two groups. RESULTS The ANCOVA revealed a significant main effect of group, but no significant main effect of acupuncture and interactions between group and acupuncture. During the pre-acupuncture resting state, ReHo values increased in the precentral gyrus (PCG), superior frontal gyrus (SFG), and insula (INS) and decreased mainly in middle temporal gyrus (MTG), parahippocampal (PHIP) and cingulate cortex in MCI patients compared with healthy controls. Furthermore, we found that the regions including precuneus (PCUN), and cingulate cortex showed increased ReHo values for MCI patients following acupuncture. For healthy controls, the medial frontal gyrus, PCG, anterior cingulate cortex (ACC) and INS showed enhanced ReHo values following acupuncture. During the post-acupuncture resting state, MCI patients showed increased ReHo values mainly in the MTG, superior parietal lobule (SPL), middle frontal gyrus (MFG), supramarginal (SMG), and PCG, and decreased ReHo values mainly in the frontal regions, PHIP, and posterior cingulated cortex (PCC) compared to healthy controls. CONCLUSION Though we found some ReHo changes between MCI patients and healthy controls, the two-way ANCOVA results showed no significant effects after multiple corrections. Further study is needed to reveal the real acupuncture effects on MCI patients.
Collapse
Affiliation(s)
- Zhenyu Liu
- Key Laboratory of Molecular Imaging and Functional Imaging, Institute of Automation, Chinese Academy of Sciences, Beijing, China
| | - Wenjuan Wei
- Key Laboratory of Molecular Imaging and Functional Imaging, Institute of Automation, Chinese Academy of Sciences, Beijing, China
| | - Lijun Bai
- Key Laboratory of Molecular Imaging and Functional Imaging, Institute of Automation, Chinese Academy of Sciences, Beijing, China
| | - Ruwei Dai
- Key Laboratory of Molecular Imaging and Functional Imaging, Institute of Automation, Chinese Academy of Sciences, Beijing, China
| | - Youbo You
- Key Laboratory of Molecular Imaging and Functional Imaging, Institute of Automation, Chinese Academy of Sciences, Beijing, China
| | - Shangjie Chen
- Department of Acupuncture and Massage, Bao’an Hospital, Southern Medical University, Shenzhen, China
| | - Jie Tian
- Key Laboratory of Molecular Imaging and Functional Imaging, Institute of Automation, Chinese Academy of Sciences, Beijing, China
- Life Sciences Research Center, School of Life Sciences and Technology, Xidian University, Xi’an, Shaanxi, China
| |
Collapse
|
16
|
Wang L, Li K, Zhang Q, Zeng Y, Dai W, Su Y, Wang G, Tan Y, Jin Z, Yu X, Si T. Short-term effects of escitalopram on regional brain function in first-episode drug-naive patients with major depressive disorder assessed by resting-state functional magnetic resonance imaging. Psychol Med 2014; 44:1417-1426. [PMID: 23942213 DOI: 10.1017/s0033291713002031] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Most knowledge regarding the effects of antidepressant drugs is at the receptor level, distal from the nervous system effects that mediate their clinical efficacy. Using functional magnetic resonance imaging (fMRI), this study investigated the effects of escitalopram, a selective serotonin reuptake inhibitor (SSRI), on resting-state brain function in patients with major depressive disorder (MDD). METHOD Fourteen first-episode drug-naive MDD patients completed two fMRI scans before and after 8 weeks of escitalopram therapy. Scans were also acquired in 14 matched healthy subjects. Data were analyzed using the regional homogeneity (ReHo) approach. RESULTS Compared to controls, MDD patients before treatment demonstrated decreased ReHo in the frontal (right superior frontal gyrus), temporal (left middle and right inferior temporal gyri), parietal (right precuneus) and occipital (left superior occipital gyrus and right cuneus) cortices, and increased ReHo in the left dorsal medial prefrontal gyrus and left anterior lobe of the cerebellum. Compared to the unmedicated state, ReHo in the patients after treatment was decreased in the left dorsal medial prefrontal gyrus, the right insula and the bilateral thalamus, and increased in the right superior frontal gyrus. Compared to controls, patients after treatment displayed a ReHo decrease in the right precuneus and a ReHo increase in the left anterior lobe of the cerebellum. CONCLUSIONS Successful treatment with escitalopram may be associated with modulation of resting-state brain activity in regions within the fronto-limbic circuit. This study provides new insight into the effects of antidepressants on functional brain systems in MDD.
Collapse
Affiliation(s)
- L Wang
- Institute of Mental Health, Peking University, Beijing, China
| | - K Li
- Department of Radiology, 306 Hospital of People's Liberation Army, Beijing, China
| | - Q Zhang
- Mood Disorders Center, Beijing Anding Hospital, Capital Medical University, Beijing, China
| | - Y Zeng
- Department of Radiology, 306 Hospital of People's Liberation Army, Beijing, China
| | - W Dai
- Institute of Mental Health, Peking University, Beijing, China
| | - Y Su
- Institute of Mental Health, Peking University, Beijing, China
| | - G Wang
- Mood Disorders Center, Beijing Anding Hospital, Capital Medical University, Beijing, China
| | - Y Tan
- Center for Psychiatric Research, Beijing Huilongguan Hospital, Beijing, China
| | - Z Jin
- Department of Radiology, 306 Hospital of People's Liberation Army, Beijing, China
| | - X Yu
- Institute of Mental Health, Peking University, Beijing, China
| | - T Si
- Institute of Mental Health, Peking University, Beijing, China
| |
Collapse
|
17
|
Identify changes of brain regional homogeneity in bipolar disorder and unipolar depression using resting-state FMRI. PLoS One 2013. [PMID: 24324588 DOI: 10.1371/journal.pone.0079999.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND To identify changes in brain activation patterns in bipolar disorder (BD) and unipolar depression (UD) patients. METHODOLOGY/PRINCIPAL FINDINGS Resting-state fMRI scans of 16 healthy controls, 17 BD and 16 UD patients were obtained. T-test of normalized regional homogeneity (ReHo) was performed in a voxel-by-voxel manner. A combined threshold of á = 0.05, minimum cluster volume of V = 10503 mm(3) (389 voxels) were used to determine ReHo differences between groups. In UD group, fMRI revealed ReHo increases in the left middle occipital lobe, right inferior parietal lobule, right precuneus and left convolution; and ReHo decreases in the left parahippocampalgyrus, right precentralgyrus, left postcentralgyrus, left precentralgyrus and left cingulated. In BD group, ReHo increases in the right insular cortex, left middle frontal gyrus, left precuneus, left occipital lobe, left parietal, left superior frontal gyrus and left thalamus; and ReHo decreases in the right anterior lobe of cerebellum, pons, right precentralgyrus, left postcentralgyrus, left inferior frontal gyrus, and right cingulate. There were some overlaps in ReHo profiles between UD and BD groups, but a marked difference was seen in the thalamus of BD. CONCLUSIONS/SIGNIFICANCE The resting-state fMRI and ReHo mapping are a promising tool to assist the detection of functional deficits and distinguish clinical and pathophysiological signs of BD and UD.
Collapse
|
18
|
Liang MJ, Zhou Q, Yang KR, Yang XL, Fang J, Chen WL, Huang Z. Identify changes of brain regional homogeneity in bipolar disorder and unipolar depression using resting-state FMRI. PLoS One 2013; 8:e79999. [PMID: 24324588 PMCID: PMC3851159 DOI: 10.1371/journal.pone.0079999] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Accepted: 09/28/2013] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND To identify changes in brain activation patterns in bipolar disorder (BD) and unipolar depression (UD) patients. METHODOLOGY/PRINCIPAL FINDINGS Resting-state fMRI scans of 16 healthy controls, 17 BD and 16 UD patients were obtained. T-test of normalized regional homogeneity (ReHo) was performed in a voxel-by-voxel manner. A combined threshold of á = 0.05, minimum cluster volume of V = 10503 mm(3) (389 voxels) were used to determine ReHo differences between groups. In UD group, fMRI revealed ReHo increases in the left middle occipital lobe, right inferior parietal lobule, right precuneus and left convolution; and ReHo decreases in the left parahippocampalgyrus, right precentralgyrus, left postcentralgyrus, left precentralgyrus and left cingulated. In BD group, ReHo increases in the right insular cortex, left middle frontal gyrus, left precuneus, left occipital lobe, left parietal, left superior frontal gyrus and left thalamus; and ReHo decreases in the right anterior lobe of cerebellum, pons, right precentralgyrus, left postcentralgyrus, left inferior frontal gyrus, and right cingulate. There were some overlaps in ReHo profiles between UD and BD groups, but a marked difference was seen in the thalamus of BD. CONCLUSIONS/SIGNIFICANCE The resting-state fMRI and ReHo mapping are a promising tool to assist the detection of functional deficits and distinguish clinical and pathophysiological signs of BD and UD.
Collapse
Affiliation(s)
- Min-Jie Liang
- Medical Imaging Center, First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, China
| | - Quan Zhou
- Medical Imaging Center, First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, China
| | - Kan-Rong Yang
- Medical Imaging Center, First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, China
| | - Xiao-Ling Yang
- Medical Imaging Center, First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, China
| | - Jin Fang
- Medical Imaging Center, First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, China
| | - Wen-Li Chen
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, South China Normal University, Guangzhou, Guangdong, China
| | - Zheng Huang
- Department of Electronic Engineering and CAPT Laboratory, University of Colorado Denver, Aurora, Colorado, United States of America
| |
Collapse
|
19
|
Lin X, Ding K, Liu Y, Yan X, Song S, Jiang T. Altered spontaneous activity in anisometropic amblyopia subjects: revealed by resting-state FMRI. PLoS One 2012; 7:e43373. [PMID: 22937041 PMCID: PMC3427333 DOI: 10.1371/journal.pone.0043373] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Accepted: 07/23/2012] [Indexed: 11/19/2022] Open
Abstract
Amblyopia, also known as lazy eye, usually occurs during early childhood and results in poor or blurred vision. Recent neuroimaging studies have found cortical structural/functional abnormalities in amblyopia. However, until now, it was still not known whether the spontaneous activity of the brain changes in amblyopia subjects. In the present study, regional homogeneity (ReHo), a measure of the homogeneity of functional magnetic resonance imaging signals, was used for the first time to investigate changes in resting-state local spontaneous brain activity in individuals with anisometropic amblyopia. Compared with age- and gender-matched subjects with normal vision, the anisometropic amblyopia subjects showed decreased ReHo of spontaneous brain activity in the right precuneus, the left medial prefrontal cortex, the left inferior frontal gyrus, and the left cerebellum, and increased ReHo of spontaneous brain activity was found in the bilateral conjunction area of the postcentral and precentral gyri, the left paracentral lobule, the left superior temporal gyrus, the left fusiform gyrus, the conjunction area of the right insula, putamen and the right middle occipital gyrus. The observed decreases in ReHo may reflect decreased visuo-motor processing ability, and the increases in ReHo in the somatosensory cortices, the motor areas and the auditory area may indicate compensatory plasticity in amblyopia.
Collapse
Affiliation(s)
- Xiaoming Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Kun Ding
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Yong Liu
- LIAMA Center for Computational Medicine, National Laboratory of Pattern Recognition, Institute of Automation, The Chinese Academy of Sciences, Beijing, China
| | - Xiaohe Yan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Shaojie Song
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Tianzi Jiang
- LIAMA Center for Computational Medicine, National Laboratory of Pattern Recognition, Institute of Automation, The Chinese Academy of Sciences, Beijing, China
- Key Laboratory for NeuroInformation of Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China
- The Queensland Brain Institute, The University of Queensland, Brisbane, Queensland, Australia
| |
Collapse
|
20
|
Zhang Z, Liu Y, Jiang T, Zhou B, An N, Dai H, Wang P, Niu Y, Wang L, Zhang X. Altered spontaneous activity in Alzheimer's disease and mild cognitive impairment revealed by Regional Homogeneity. Neuroimage 2011; 59:1429-40. [PMID: 21907292 DOI: 10.1016/j.neuroimage.2011.08.049] [Citation(s) in RCA: 201] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2011] [Revised: 08/14/2011] [Accepted: 08/17/2011] [Indexed: 11/26/2022] Open
Abstract
Alzheimer's disease (AD), the most prevalent cause of dementia in the elderly, is characterized by progressive cognitive and intellectual deficits. Most patients with mild cognitive impairment (MCI) are thought to be in a very early stage of AD. Resting-state functional magnetic resonance imaging reflects spontaneous brain activities and/or the endogenous/background neurophysiological process of the human brain. Regional Homogeneity (ReHo) can provide a fast method for mapping regional activity across the whole brain. Little has been previously published about where or how spontaneous activity differs between MCI and AD, although many previous fMRI studies have shown that the activity pattern is altered in MCI/AD. In the present study, we first used the ReHo method to explore differences in regional spontaneous activities throughout the whole brain between normal controls (NC) and people with MCI and with AD. A one-way ANOVA was performed to determine the regions in which the ReHo differs between the three groups, and then a post hoc analysis was performed to evaluate differences in the pattern among the three groups. Finally a correlation analysis was done between the ReHo index of these regions and clinical variables in order to evaluate the relationship between ReHo and cognitive measures in the AD and MCI groups. An exploratory classification analysis also demonstrated that ReHo measures were able to correctly separate subjects in 71.4% of the cases. Altered brain spontaneous activations were found in the medial prefrontal cortex, the bilateral posterior cingulate gyrus/precuneus and the left inferior parietal lobule (IPL) in both MCI and AD. In MCI, the ReHo index in the left IPL was higher than that of the NC, which could indicate the presence of a compensatory mechanism in MCI. More obviously, the correlation analysis indicated that the lower the memory and other cognitive abilities, the lower the ReHo in patients with MCI and AD. Combining our findings with the results in earlier studies, we propose that the spontaneous activity pattern in the resting state could potentially be used as a clinical marker for MCI/AD.
Collapse
Affiliation(s)
- Zengqiang Zhang
- Department of Neurology, Institute of Geriatrics and Gerontology, Chinese PLA General Hospital, Beijing 100853, China
| | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Waters-Metenier SL, Toulopoulou T. Qualifying brain functional MRI parameters as endophenotypes in schizophrenia. FUTURE NEUROLOGY 2010. [DOI: 10.2217/fnl.10.68] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Although the genetic contribution to schizophrenia pathogenesis has been well established, with an approximate heritability of 81%, the endeavor to elucidate the complex genetic architecture of schizophrenia has met limited success. ‘Endophenotypes’, or ‘intermediate phenotypes’, are more restricted constructs of genetic risk than the clinical manifestations hitherto employed by molecular geneticists. They are, putatively, intermediate in the pathophysiological pathway between genetic variation and clinical phenomenology and can possibly be used to assist in the elucidation of genetic diathesis for schizophrenia. In this article, we present the current evidence that supports functional MRI parameters as promising candidate endophenotypes in schizophrenia.
Collapse
Affiliation(s)
- Sheena Lindsey Waters-Metenier
- Department of Psychosis Studies, King’s College London, King’s Health Partners, Institute of Psychiatry, London SE5 8AF, UK
| | | |
Collapse
|
22
|
Littow H, Elseoud AA, Haapea M, Isohanni M, Moilanen I, Mankinen K, Nikkinen J, Rahko J, Rantala H, Remes J, Starck T, Tervonen O, Veijola J, Beckmann C, Kiviniemi VJ. Age-Related Differences in Functional Nodes of the Brain Cortex - A High Model Order Group ICA Study. Front Syst Neurosci 2010; 4. [PMID: 20953235 PMCID: PMC2955419 DOI: 10.3389/fnsys.2010.00032] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2010] [Accepted: 06/18/2010] [Indexed: 12/03/2022] Open
Abstract
Functional MRI measured with blood oxygen dependent (BOLD) contrast in the absence of intermittent tasks reflects spontaneous activity of so-called resting state networks (RSN) of the brain. Group level independent component analysis (ICA) of BOLD data can separate the human brain cortex into 42 independent RSNs. In this study we evaluated age-related effects from primary motor and sensory, and, higher level control RSNs. One hundred sixty-eight healthy subjects were scanned and divided into three groups: 55 adolescents (ADO, 13.2 ± 2.4 years), 59 young adults (YA, 22.2 ± 0.6 years), and 54 older adults (OA, 42.7 ± 0.5 years), all with normal IQ. High model order group probabilistic ICA components (70) were calculated and dual-regression analysis was used to compare 21 RSN's spatial differences between groups. The power spectra were derived from individual ICA mixing matrix time series of the group analyses for frequency domain analysis. We show that primary sensory and motor networks tend to alter more in younger age groups, whereas associative and higher level cognitive networks consolidate and re-arrange until older adulthood. The change has a common trend: both spatial extent and the low frequency power of the RSN's reduce with increasing age. We interpret these result as a sign of normal pruning via focusing of activity to less distributed local hubs.
Collapse
Affiliation(s)
- Harri Littow
- Department of Diagnostic Radiology, Oulu University Hospital Oulu, Finland
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Zhou Y, Wang K, Liu Y, Song M, Song SW, Jiang T. Spontaneous brain activity observed with functional magnetic resonance imaging as a potential biomarker in neuropsychiatric disorders. Cogn Neurodyn 2010; 4:275-94. [PMID: 22132039 DOI: 10.1007/s11571-010-9126-9] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2010] [Revised: 07/18/2010] [Accepted: 07/21/2010] [Indexed: 12/01/2022] Open
Abstract
As functional magnetic resonance imaging (fMRI) studies have yielded increasing amounts of information about the brain's spontaneous activity, they have revealed fMRI's potential to locate changes in brain hemodynamics that are associated with neuropsychiatric disorders. In this paper, we review studies that support the notion that changes in brain spontaneous activity observed by fMRI can be used as potential biomarkers for diagnosis and treatment evaluation in neuropsychiatric disorders. We first review the methods used to study spontaneous activity from the perspectives of (1) the properties of local spontaneous activity, (2) the spatial pattern of spontaneous activity, and (3) the topological properties of brain networks. We also summarize the major findings associated with major neuropsychiatric disorders obtained using these methods. Then we review the pilot studies that have used spontaneous activity to discriminate patients from normal controls. Finally, we discuss current challenges and potential research directions to further elucidate the clinical use of spontaneous brain activity in neuropsychiatric disorders.
Collapse
|
24
|
Hlinka J, Alexakis C, Diukova A, Liddle PF, Auer DP. Slow EEG pattern predicts reduced intrinsic functional connectivity in the default mode network: an inter-subject analysis. Neuroimage 2010; 53:239-46. [PMID: 20538065 DOI: 10.1016/j.neuroimage.2010.06.002] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2009] [Revised: 05/15/2010] [Accepted: 06/02/2010] [Indexed: 10/19/2022] Open
Abstract
The last two decades have witnessed great progress in mapping neural networks associated with task-induced brain activation. More recently, identification of resting state networks (RSN) paved the way to investigate spontaneous task-unrelated brain activity. The cardinal features characterising RSN are low-frequency fluctuations of blood oxygenation level dependent (BOLD) signals synchronised between spatially distinct, but functionally connected brain areas. Simultaneous EEG/fMRI has been previously deployed to study the neurophysiological signature of RSN by comparing EEG power with BOLD amplitudes. We hypothesised that band-limited EEG power may be directly related to network-specific functional connectivity (FC) of BOLD signal time courses. Hence, we studied the association between individual EEG signature and FC in a core RSN, the so-called default mode network (DMN). Combined EEG/fMRI data of 20 healthy volunteers collected during a 15-minute rest period were analysed. Using an inter-subject analysis design, we demonstrated a network and frequency specific relation between RSN FC and EEG. In a multiple regression model, EEG band-powers explained 70% of DMN FC variance, with significant partial correlations of DMN FC to delta (r=-0.73) and beta (r=0.53) power. The identified EEG pattern has been previously associated with increased alertness. Conversely, an established EEG-derived sedation index (spectral edge frequency SEF95) closely correlated with DMN FC. The study presents an approach that opens a new perspective to EEG/fMRI correlation. Direct evidence was provided for a distinct neurophysiological correlate of DMN FC. This finding further validates the biological relevance of network-specific intrinsic FC and provides an initial neurophysiological basis for interpreting studies of DMN FC alterations.
Collapse
Affiliation(s)
- Jaroslav Hlinka
- Division of Academic Radiology, School of Clinical Sciences, University of Nottingham, Nottingham, UK.
| | | | | | | | | |
Collapse
|
25
|
Kiviniemi V, Starck T, Remes J, Long X, Nikkinen J, Haapea M, Veijola J, Moilanen I, Isohanni M, Zang YF, Tervonen O. Functional segmentation of the brain cortex using high model order group PICA. Hum Brain Mapp 2010; 30:3865-86. [PMID: 19507160 DOI: 10.1002/hbm.20813] [Citation(s) in RCA: 283] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Baseline activity of resting state brain networks (RSN) in a resting subject has become one of the fastest growing research topics in neuroimaging. It has been shown that up to 12 RSNs can be differentiated using an independent component analysis (ICA) of the blood oxygen level dependent (BOLD) resting state data. In this study, we investigate how many RSN signal sources can be separated from the entire brain cortex using high dimension ICA analysis from a group dataset. Group data from 55 subjects was analyzed using temporal concatenation and a probabilistic independent component analysis algorithm. ICA repeatability testing verified that 60 of the 70 computed components were robustly detectable. Forty-two independent signal sources were identifiable as RSN, and 28 were related to artifacts or other noninterest sources (non-RSN). The depicted RSNs bore a closer match to functional neuroanatomy than the previously reported RSN components. The non-RSN sources have significantly lower temporal intersource connectivity than the RSN (P < 0.0003). We conclude that the high model order ICA of the group BOLD data enables functional segmentation of the brain cortex. The method enables new approaches to causality and connectivity analysis with more specific anatomical details.
Collapse
Affiliation(s)
- Vesa Kiviniemi
- Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Seghier ML, Hüppi PS. The role of functional magnetic resonance imaging in the study of brain development, injury, and recovery in the newborn. Semin Perinatol 2010; 34:79-86. [PMID: 20109975 DOI: 10.1053/j.semperi.2009.10.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Development of brain functions and the structural-functional correlates of brain injury remain difficult to evaluate in the young infant. Thus, new noninvasive methods capable of early functional diagnosis are needed. This review describes the use of functional magnetic resonance imaging (fMRI) for studying localization of brain function in the developing brain when standard clinical investigations are not available or conclusive. This promising neuroimaging technique has been successfully used in healthy newborns and in newborns with brain injury using different paradigms, including passive visual, somato-sensorial, and auditory stimulation. We summarize the major findings of previous fMRI studies in young infants, describe ongoing methodological challenges, and propose exciting future developments in using resting-state protocols and functional connectivity techniques to assist in evaluating early life brain function and its recovery from injury.
Collapse
Affiliation(s)
- Mohamed L Seghier
- Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, London, United Kingdom.
| | | |
Collapse
|
27
|
|
28
|
Kiviniemi V, Remes J, Starck T, Nikkinen J, Haapea M, Silven O, Tervonen O. Mapping Transient Hyperventilation Induced Alterations with Estimates of the Multi-Scale Dynamics of BOLD Signal. Front Neuroinform 2009; 3:18. [PMID: 19636388 PMCID: PMC2715265 DOI: 10.3389/neuro.11.018.2009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2009] [Accepted: 06/22/2009] [Indexed: 11/24/2022] Open
Abstract
Temporal blood oxygen level dependent (BOLD) contrast signals in functional MRI during rest may be characterized by power spectral distribution (PSD) trends of the form 1/f(alpha). Trends with 1/f characteristics comprise fractal properties with repeating oscillation patterns in multiple time scales. Estimates of the fractal properties enable the quantification of phenomena that may otherwise be difficult to measure, such as transient, non-linear changes. In this study it was hypothesized that the fractal metrics of 1/f BOLD signal trends can map changes related to dynamic, multi-scale alterations in cerebral blood flow (CBF) after a transient hyperventilation challenge. Twenty-three normal adults were imaged in a resting-state before and after hyperventilation. Different variables (1/f trend constant alpha, fractal dimension D(f), and, Hurst exponent H) characterizing the trends were measured from BOLD signals. The results show that fractal metrics of the BOLD signal follow the fractional Gaussian noise model, even during the dynamic CBF change that follows hyperventilation. The most dominant effect on the fractal metrics was detected in grey matter, in line with previous hyperventilation vaso-reactivity studies. The alpha was able to differentiate also blood vessels from grey matter changes. D(f) was most sensitive to grey matter. H correlated with default mode network areas before hyperventilation but this pattern vanished after hyperventilation due to a global increase in H. In the future, resting-state fMRI combined with fractal metrics of the BOLD signal may be used for analyzing multi-scale alterations of cerebral blood flow.
Collapse
Affiliation(s)
- Vesa Kiviniemi
- Department of Diagnostic Radiology, Oulu University HospitalOulu, Finland
| | - Jukka Remes
- Department of Diagnostic Radiology, Oulu University HospitalOulu, Finland
- Department of Information and Electrical Engineering, University of OuluOulu, Finland
| | - Tuomo Starck
- Department of Diagnostic Radiology, Oulu University HospitalOulu, Finland
| | - Juha Nikkinen
- Department of Diagnostic Radiology, Oulu University HospitalOulu, Finland
| | - Marianne Haapea
- Department of Diagnostic Radiology, Oulu University HospitalOulu, Finland
| | - Olli Silven
- Department of Information and Electrical Engineering, University of OuluOulu, Finland
| | - Osmo Tervonen
- Department of Diagnostic Radiology, Oulu University HospitalOulu, Finland
| |
Collapse
|
29
|
Bandettini PA, Bullmore E. Endogenous oscillations and networks in functional magnetic resonance imaging. Hum Brain Mapp 2008; 29:737-9. [PMID: 18465798 PMCID: PMC2715869 DOI: 10.1002/hbm.20607] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Peter A. Bandettini
- Section on Functional Imaging Methods, Laboratory of Brain and Cognition, National Institute of Mental Health, Bethesda, Maryland
| | - Ed Bullmore
- Brain Mapping Unit and Behavioural and Clinical Neurosciences Institute, University of Cambridge, Cambridge, United Kingdom
| |
Collapse
|