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Sunil S, Jiang J, Shah S, Kura S, Kilic K, Erdener SE, Ayata C, Devor A, Boas DA. Neurovascular coupling is preserved in chronic stroke recovery after targeted photothrombosis. Neuroimage Clin 2023; 38:103377. [PMID: 36948140 PMCID: PMC10034641 DOI: 10.1016/j.nicl.2023.103377] [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: 10/13/2022] [Revised: 03/07/2023] [Accepted: 03/09/2023] [Indexed: 03/17/2023]
Abstract
Functional neuroimaging, which measures hemodynamic responses to brain activity, has great potential for monitoring recovery in stroke patients and guiding rehabilitation during recovery. However, hemodynamic responses after stroke are almost always altered relative to responses in healthy subjects and it is still unclear if these alterations reflect the underlying brain physiology or if the alterations are purely due to vascular injury. In other words, we do not know the effect of stroke on neurovascular coupling and are therefore limited in our ability to use functional neuroimaging to accurately interpret stroke pathophysiology. To address this challenge, we simultaneously captured neural activity, through fluorescence calcium imaging, and hemodynamics, through intrinsic optical signal imaging, during longitudinal stroke recovery. Our data suggest that neurovascular coupling was preserved in the chronic phase of recovery (2 weeks and 4 weeks post-stoke) and resembled pre-stroke neurovascular coupling. This indicates that functional neuroimaging faithfully represents the underlying neural activity in chronic stroke. Further, neurovascular coupling in the sub-acute phase of stroke recovery was predictive of long-term behavioral outcomes. Stroke also resulted in increases in global brain oscillations, which showed distinct patterns between neural activity and hemodynamics. Increased neural excitability in the contralesional hemisphere was associated with increased contralesional intrahemispheric connectivity. Additionally, sub-acute increases in hemodynamic oscillations were associated with improved sensorimotor outcomes. Collectively, these results support the use of hemodynamic measures of brain activity post-stroke for predicting functional and behavioral outcomes.
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Affiliation(s)
- Smrithi Sunil
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA.
| | - John Jiang
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Shashwat Shah
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Sreekanth Kura
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Kivilcim Kilic
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Sefik Evren Erdener
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| | - Cenk Ayata
- Departments of Neurology and Radiology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Anna Devor
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA; Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, MA 02114, USA
| | - David A Boas
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA.
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Novi SL, Carvalho AC, Forti RM, Cendes F, Yasuda CL, Mesquita RC. Revealing the spatiotemporal requirements for accurate subject identification with resting-state functional connectivity: a simultaneous fNIRS-fMRI study. NEUROPHOTONICS 2023; 10:013510. [PMID: 36756003 PMCID: PMC9896013 DOI: 10.1117/1.nph.10.1.013510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 01/10/2023] [Indexed: 06/18/2023]
Abstract
SIGNIFICANCE Brain fingerprinting refers to identifying participants based on their functional patterns. Despite its success with functional magnetic resonance imaging (fMRI), brain fingerprinting with functional near-infrared spectroscopy (fNIRS) still lacks adequate validation. AIM We investigated how fNIRS-specific acquisition features (limited spatial information and nonneural contributions) influence resting-state functional connectivity (rsFC) patterns at the intra-subject level and, therefore, brain fingerprinting. APPROACH We performed multiple simultaneous fNIRS and fMRI measurements in 29 healthy participants at rest. Data were preprocessed following the best practices, including the removal of motion artifacts and global physiology. The rsFC maps were extracted with the Pearson correlation coefficient. Brain fingerprinting was tested with pairwise metrics and a simple linear classifier. RESULTS Our results show that average classification accuracy with fNIRS ranges from 75% to 98%, depending on the number of runs and brain regions used for classification. Under the right conditions, brain fingerprinting with fNIRS is close to the 99.9% accuracy found with fMRI. Overall, the classification accuracy is more impacted by the number of runs and the spatial coverage than the choice of the classification algorithm. CONCLUSIONS This work provides evidence that brain fingerprinting with fNIRS is robust and reliable for extracting unique individual features at the intra-subject level once relevant spatiotemporal constraints are correctly employed.
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Affiliation(s)
- Sergio L. Novi
- University of Campinas, “Gleb Wataghin” Institute of Physics, Campinas, Brazil
- Western University, Department of Physiology and Pharmacology, London, Ontario, Canada
| | - Alex C. Carvalho
- University of Campinas, “Gleb Wataghin” Institute of Physics, Campinas, Brazil
- University of Campinas, Laboratory of Neuroimaging, Campinas, Brazil
| | - R. M. Forti
- University of Campinas, “Gleb Wataghin” Institute of Physics, Campinas, Brazil
- The Children’s Hospital of Philadelphia, Division of Neurology, Philadelphia, Pennsylvania, United States
| | - Fernado Cendes
- Brazilian Institute of Neuroscience and Neurotechnology, Campinas, Brazil
- University of Campinas, School of Medical Sciences, Department of Neurology, Campinas, Brazil
| | - Clarissa L. Yasuda
- University of Campinas, Laboratory of Neuroimaging, Campinas, Brazil
- Brazilian Institute of Neuroscience and Neurotechnology, Campinas, Brazil
- University of Campinas, School of Medical Sciences, Department of Neurology, Campinas, Brazil
| | - Rickson C. Mesquita
- University of Campinas, “Gleb Wataghin” Institute of Physics, Campinas, Brazil
- Brazilian Institute of Neuroscience and Neurotechnology, Campinas, Brazil
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Jiang S, Carpenter LL, Jiang H. Optical neuroimaging: advancing transcranial magnetic stimulation treatments of psychiatric disorders. Vis Comput Ind Biomed Art 2022; 5:22. [PMID: 36071259 PMCID: PMC9452613 DOI: 10.1186/s42492-022-00119-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 08/22/2022] [Indexed: 11/10/2022] Open
Abstract
Transcranial magnetic stimulation (TMS) has been established as an important and effective treatment for various psychiatric disorders. However, its effectiveness has likely been limited due to the dearth of neuronavigational tools for targeting purposes, unclear ideal stimulation parameters, and a lack of knowledge regarding the physiological response of the brain to TMS in each psychiatric condition. Modern optical imaging modalities, such as functional near-infrared spectroscopy and diffuse optical tomography, are promising tools for the study of TMS optimization and functional targeting in psychiatric disorders. They possess a unique combination of high spatial and temporal resolutions, portability, real-time capability, and relatively low costs. In this mini-review, we discuss the advent of optical imaging techniques and their innovative use in several psychiatric conditions including depression, panic disorder, phobias, and eating disorders. With further investment and research in the development of these optical imaging approaches, their potential will be paramount for the advancement of TMS treatment protocols in psychiatry.
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Abdalmalak A, Novi SL, Kazazian K, Norton L, Benaglia T, Slessarev M, Debicki DB, Lawrence KS, Mesquita RC, Owen AM. Effects of Systemic Physiology on Mapping Resting-State Networks Using Functional Near-Infrared Spectroscopy. Front Neurosci 2022; 16:803297. [PMID: 35350556 PMCID: PMC8957952 DOI: 10.3389/fnins.2022.803297] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 02/07/2022] [Indexed: 12/11/2022] Open
Abstract
Resting-state functional connectivity (rsFC) has gained popularity mainly due to its simplicity and potential for providing insights into various brain disorders. In this vein, functional near-infrared spectroscopy (fNIRS) is an attractive choice due to its portability, flexibility, and low cost, allowing for bedside imaging of brain function. While promising, fNIRS suffers from non-neural signal contaminations (i.e., systemic physiological noise), which can increase correlation across fNIRS channels, leading to spurious rsFC networks. In the present work, we hypothesized that additional measurements with short channels, heart rate, mean arterial pressure, and end-tidal CO2 could provide a better understanding of the effects of systemic physiology on fNIRS-based resting-state networks. To test our hypothesis, we acquired 12 min of resting-state data from 10 healthy participants. Unlike previous studies, we investigated the efficacy of different pre-processing approaches in extracting resting-state networks. Our results are in agreement with previous studies and reinforce the fact that systemic physiology can overestimate rsFC. We expanded on previous work by showing that removal of systemic physiology decreases intra- and inter-subject variability, increasing the ability to detect neural changes in rsFC across groups and over longitudinal studies. Our results show that by removing systemic physiology, fNIRS can reproduce resting-state networks often reported with functional magnetic resonance imaging (fMRI). Finally, the present work details the effects of systemic physiology and outlines how to remove (or at least ameliorate) their contributions to fNIRS signals acquired at rest.
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Affiliation(s)
- Androu Abdalmalak
- Department of Physiology and Pharmacology, Western University, London, ON, Canada
- Brain and Mind Institute, Western University, London, ON, Canada
- *Correspondence: Androu Abdalmalak,
| | - Sergio L. Novi
- “Gleb Wataghin” Institute of Physics, University of Campinas, Campinas, Brazil
- *Correspondence: Androu Abdalmalak,
| | - Karnig Kazazian
- Brain and Mind Institute, Western University, London, ON, Canada
| | - Loretta Norton
- Department of Psychology, King’s University College at Western University, London, ON, Canada
| | - Tatiana Benaglia
- Institute of Mathematics, Statistics and Scientific Computing, University of Campinas, Campinas, Brazil
| | - Marat Slessarev
- Clinical Neurological Sciences, Western University, London, ON, Canada
| | - Derek B. Debicki
- Brain and Mind Institute, Western University, London, ON, Canada
- Clinical Neurological Sciences, Western University, London, ON, Canada
| | - Keith St. Lawrence
- Department of Medical Biophysics, Western University, London, ON, Canada
| | - Rickson C. Mesquita
- “Gleb Wataghin” Institute of Physics, University of Campinas, Campinas, Brazil
| | - Adrian M. Owen
- Department of Physiology and Pharmacology, Western University, London, ON, Canada
- Brain and Mind Institute, Western University, London, ON, Canada
- Department of Psychology, Western University, London, ON, Canada
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Maria A, Hirvi P, Kotilahti K, Heiskala J, Tuulari JJ, Karlsson L, Karlsson H, Nissilä I. Imaging affective and non-affective touch processing in two-year-old children. Neuroimage 2022; 251:118983. [PMID: 35149231 DOI: 10.1016/j.neuroimage.2022.118983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 12/22/2021] [Accepted: 02/07/2022] [Indexed: 10/19/2022] Open
Abstract
Touch is an important component of early parent-child interaction and plays a critical role in the socio-emotional development of children. However, there are limited studies on touch processing amongst children in the age range from one to three years. The present study used frequency-domain diffuse optical tomography (DOT) to investigate the processing of affective and non-affective touch over left frontotemporal brain areas contralateral to the stimulated forearm in two-year-old children. Affective touch was administered by a single stroke with a soft brush over the child's right dorsal forearm at 3 cm/s, while non-affective touch was provided by multiple brush strokes at 30 cm/s. We found that in the insula, the total haemoglobin (HbT) response to slow brushing was significantly greater than the response to fast brushing (slow > fast). Additionally, a region in the postcentral gyrus, Rolandic operculum and superior temporal gyrus exhibited greater response to fast brushing than slow brushing (fast > slow). These findings confirm that an adult-like pattern of haemodynamic responses to affective and non-affective touch can be recorded in two-year-old subjects using DOT. To improve the accuracy of modelling light transport in the two-year-old subjects, we used a published age-appropriate atlas and deformed it to match the exterior shape of each subject's head. We estimated the combined scalp and skull, and grey matter (GM) optical properties by fitting simulated data to calibrated and coupling error corrected phase and amplitude measurements. By utilizing a two-compartment cerebrospinal fluid (CSF) model, the accuracy of estimation of GM optical properties and the localization of activation in the insula was improved. The techniques presented in this paper can be used to study neural development of children at different ages and illustrate that the technology is well-tolerated by most two-year-old children and not excessively sensitive to subject movement. The study points the way towards exciting possibilities in functional imaging of deeper functional areas near sulci in small children.
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Affiliation(s)
- Ambika Maria
- University of Turku, Department of Clinical Medicine, Turku Brain and Mind Center, FinnBrain Birth Cohort Study, Finland; University of Turku and Turku University Hospital, Department of Psychiatry, Finland
| | - Pauliina Hirvi
- Aalto University, Department of Neuroscience and Biomedical Engineering, P.O. Box 12200, AALTO FI-00076, Finland; Aalto University, Department of Mathematics and Systems Analysis, Finland
| | - Kalle Kotilahti
- Aalto University, Department of Neuroscience and Biomedical Engineering, P.O. Box 12200, AALTO FI-00076, Finland; University of Turku, Department of Clinical Medicine, Turku Brain and Mind Center, FinnBrain Birth Cohort Study, Finland
| | - Juha Heiskala
- HUS Medical Imaging Center, Clinical Neurophysiology; Clinical Neurosciences, Helsinki, University Hospital and University of Helsinki, Helsinki, Finland
| | - Jetro J Tuulari
- University of Turku, Department of Clinical Medicine, Turku Brain and Mind Center, FinnBrain Birth Cohort Study, Finland; University of Turku and Turku University Hospital, Department of Psychiatry, Finland; Turku Collegium for Science, Medicine and Technology, TCSMT, University of Turku, Finland
| | - Linnea Karlsson
- University of Turku, Department of Clinical Medicine, Turku Brain and Mind Center, FinnBrain Birth Cohort Study, Finland; University of Turku and Turku University Hospital, Department of Psychiatry, Finland; University of Turku and Turku University Hospital, Department of Paediatrics and Adolescent Medicine, Finland; Centre for Population Health Research, Turku University Hospital and University of Turku, Turku, Finland
| | - Hasse Karlsson
- University of Turku, Department of Clinical Medicine, Turku Brain and Mind Center, FinnBrain Birth Cohort Study, Finland; University of Turku and Turku University Hospital, Department of Psychiatry, Finland
| | - Ilkka Nissilä
- Aalto University, Department of Neuroscience and Biomedical Engineering, P.O. Box 12200, AALTO FI-00076, Finland.
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Ren Y, Cui G, Zhang X, Feng K, Yu C, Liu P. The promising fNIRS: Uncovering the function of prefrontal working memory networks based on multi-cognitive tasks. Front Psychiatry 2022; 13:985076. [PMID: 36386968 PMCID: PMC9640951 DOI: 10.3389/fpsyt.2022.985076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Accepted: 10/04/2022] [Indexed: 11/13/2022] Open
Abstract
The diversity of cognitive task paradigms using functional near-infrared spectroscopy (fNIRS) and the lack of theoretical explanations for these functional imaging atlases have greatly hindered the application of fNIRS in psychiatry. The fNIRS brain imaging based on multiple cognitive tasks could generally reflect the working patterns and neurovascular coupling changes in the prefrontal working memory network. By alternating the stimulation patterns of resting and task states, six typical symptom-related functional brain imaging waveforms related to psychiatric disorders are identified and three joint networks of the prefrontal working memory, namely, the attentional working memory primary coordination network, the perceptual content working memory secondary network, and the emotional-behavioral working memory executive network, are initially represented. This is the first attempt to characterize the cognitive, emotional, and behavioral regulation of the prefrontal working memory network using fNIRS, which may promote the application of fNIRS in clinical settings.
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Affiliation(s)
- Yufei Ren
- Department of Foreign Languages and Literatures, Tsinghua University, Beijing, China
| | - Gang Cui
- Department of Foreign Languages and Literatures, Tsinghua University, Beijing, China
| | - Xiaoqian Zhang
- Department of Psychiatry, Yuquan Hospital, Tsinghua University, Beijing, China
| | - Kun Feng
- Department of Psychiatry, Yuquan Hospital, Tsinghua University, Beijing, China
| | | | - Pozi Liu
- Department of Psychiatry, Yuquan Hospital, Tsinghua University, Beijing, China.,School of Clinical Medicine, Tsinghua University, Beijing, China
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Khan AF, Zhang F, Yuan H, Ding L. Brain-wide functional diffuse optical tomography of resting state networks. J Neural Eng 2021; 18. [PMID: 33946052 DOI: 10.1088/1741-2552/abfdf9] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Accepted: 05/04/2021] [Indexed: 02/07/2023]
Abstract
Objective.Diffuse optical tomography (DOT) has the potential in reconstructing resting state networks (RSNs) in human brains with high spatio-temporal resolutions and multiple contrasts. While several RSNs have been reported and successfully reconstructed using DOT, its full potential in recovering a collective set of distributed brain-wide networks with the number of RSNs close to those reported using functional magnetic resonance imaging (fMRI) has not been demonstrated.Approach.The present study developed a novel brain-wide DOT (BW-DOT) framework that integrates a cap-based whole-head optode placement system with multiple computational approaches, i.e. finite-element modeling, inverse source reconstruction, data-driven pattern recognition, and statistical correlation tomography, to reconstruct RSNs in dual contrasts of oxygenated (HbO) and deoxygenated hemoglobins (HbR).Main results.Our results from the proposed framework revealed a comprehensive set of RSNs and their subnetworks, which collectively cover almost the entire neocortical surface of the human brain, both at the group level and individual participants. The spatial patterns of these DOT RSNs suggest statistically significant similarities to fMRI RSN templates. Our results also reported the networks involving the medial prefrontal cortex and precuneus that had been missed in previous DOT studies. Furthermore, RSNs obtained from HbO and HbR suggest similarity in terms of both the number of RSN types reconstructed and their corresponding spatial patterns, while HbR RSNs show statistically more similarity to fMRI RSN templates and HbO RSNs indicate more bilateral patterns over two hemispheres. In addition, the BW-DOT framework allowed consistent reconstructions of RSNs across individuals and across recording sessions, indicating its high robustness and reproducibility, respectively.Significance.Our present results suggest the feasibility of using the BW-DOT, as a neuroimaging tool, in simultaneously mapping multiple RSNs and its potential values in studying RSNs, particularly in patient populations under diverse conditions and needs, due to its advantages in accessibility over fMRI.
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Affiliation(s)
- Ali F Khan
- Stephenson School of Biomedical Engineering, University of Oklahoma, Norman, OK, United States of America
| | - Fan Zhang
- Stephenson School of Biomedical Engineering, University of Oklahoma, Norman, OK, United States of America
| | - Han Yuan
- Stephenson School of Biomedical Engineering, University of Oklahoma, Norman, OK, United States of America.,Institute for Biomedical Engineering, Science, and Technology, University of Oklahoma, Norman, OK, United States of America
| | - Lei Ding
- Stephenson School of Biomedical Engineering, University of Oklahoma, Norman, OK, United States of America.,Institute for Biomedical Engineering, Science, and Technology, University of Oklahoma, Norman, OK, United States of America
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Optimal Spectral Combination of a Hyperspectral Camera for Intraoperative Hemodynamic and Metabolic Brain Mapping. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10155158] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Intraoperative optical imaging is a localization technique for the functional areas of the human brain cortex during neurosurgical procedures. These areas are assessed by monitoring the oxygenated (HbO2) and deoxygenated hemoglobin (Hb) concentration changes occurring in the brain. Sometimes, the functional status of the brain is assessed using metabolic biomarkers: the oxidative state of cytochrome-c-oxidase (oxCCO). A setup composed of a white light source and a hyperspectral or a standard RGB camera could be used to identify the functional areas. The choice of the best spectral configuration is still based on an empirical approach. We propose in this study a method to define the optimal spectral combinations of a commercial hyperspectral camera for the computation of hemodynamic and metabolic brain maps. The method is based on a Monte Carlo framework that simulates the acquisition of the intrinsic optical signal following a neuronal activation. The results indicate that the optimal spectral combination of a hyperspectral camera aims to accurately quantify the HbO2 (0.5% error), Hb (4.4% error), and oxCCO (15% error) responses in the brain following neuronal activation. We also show that RGB imaging is a low cost and accurate solution to compute Hb maps (4% error), but not accurate to compute HbO2 (48% error) or oxCCO (1036% error) maps.
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Mc Larney B, Hutter MA, Degtyaruk O, Deán-Ben XL, Razansky D. Monitoring of Stimulus Evoked Murine Somatosensory Cortex Hemodynamic Activity With Volumetric Multi-Spectral Optoacoustic Tomography. Front Neurosci 2020; 14:536. [PMID: 32581686 PMCID: PMC7283916 DOI: 10.3389/fnins.2020.00536] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 05/01/2020] [Indexed: 01/17/2023] Open
Abstract
Sensory stimulation is an attractive paradigm for studying brain activity using various optical-, ultrasound- and MRI-based functional neuroimaging methods. Optoacoustics has been recently suggested as a powerful new tool for scalable mapping of multiple hemodynamic parameters with rich contrast and previously unachievable spatio-temporal resolution. Yet, its utility for studying the processing of peripheral inputs at the whole brain level has so far not been quantified. We employed volumetric multi-spectral optoacoustic tomography (vMSOT) to non-invasively monitor the HbO, HbR, and HbT dynamics across the mouse somatosensory cortex evoked by electrical paw stimuli. We show that elevated contralateral activation is preserved in the HbO map (invisible to MRI) under isoflurane anesthesia. Brain activation is shown to be predominantly confined to the somatosensory cortex, with strongest activation in the hindpaw region of the contralateral sensorimotor cortex. Furthermore, vMSOT detected the presence of an initial dip in the contralateral hindpaw region in the delta HbO channel. Sensorimotor cortical activity was identified over all other regions in HbT and HbO but not in HbR. Pearson’s correlation mapping enabled localizing the response to the sensorimotor cortex further highlighting the ability of vMSOT to bridge over imaging performance deficiencies of other functional neuroimaging modalities.
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Affiliation(s)
- Benedict Mc Larney
- Faculty of Medicine, Technical University of Munich, Munich, Germany.,Institute for Biological and Medical Imaging, Helmholtz Center Munich, Munich, Germany
| | | | - Oleksiy Degtyaruk
- Institute for Biological and Medical Imaging, Helmholtz Center Munich, Munich, Germany.,Faculty of Medicine and Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
| | - Xosé Luís Deán-Ben
- Faculty of Medicine and Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland.,Institute for Biomedical Engineering and Department of Information Technology and Electrical Engineering, Eidgenössische Technische Hochschule (ETH) Zürich, Zurich, Switzerland
| | - Daniel Razansky
- Faculty of Medicine, Technical University of Munich, Munich, Germany.,Institute for Biological and Medical Imaging, Helmholtz Center Munich, Munich, Germany.,Faculty of Medicine and Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland.,Institute for Biomedical Engineering and Department of Information Technology and Electrical Engineering, Eidgenössische Technische Hochschule (ETH) Zürich, Zurich, Switzerland
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Maria A, Nissilä I, Shekhar S, Kotilahti K, Tuulari JJ, Hirvi P, Huotilainen M, Heiskala J, Karlsson L, Karlsson H. Relationship between maternal pregnancy-related anxiety and infant brain responses to emotional speech - a pilot study. J Affect Disord 2020; 262:62-70. [PMID: 31710930 DOI: 10.1016/j.jad.2019.10.047] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 09/09/2019] [Accepted: 10/28/2019] [Indexed: 01/24/2023]
Abstract
BACKGROUND Maternal pregnancy-related anxiety (PRA) is reportedly related to neurodevelopmental outcomes of infants. However, the relationship between maternal PRA and the processing of emotions in the infant brain has not been extensively studied with neuroimaging. The objective of the present pilot study is to investigate the relationship between maternal PRA and infant hemodynamic responses to emotional speech at two months of age. METHODS The study sample included 19 mother-infant dyads from a general sample of a population of Caucasian mothers. Self-reported Pregnancy-Related Anxiety Questionnaire (PRAQ-R2) data was collected from mothers during pregnancy at gestational weeks (gwks) 24 (N = 19) and 34 (N = 18). When their infants were two months old, the infants' brains functional responses to emotional speech in the left fronto-temporoparietal cortex were recorded using diffuse optical tomography (DOT). RESULTS Maternal PRAQ-R2 scores at gwk 24 correlated negatively with the total hemoglobin (HbT) responses to sad speech on both sides of the temporoparietal junction (Spearman's rank correlation coefficient ρ = -0.87). The correlation was significantly greater at gwk 24 than gwk 34 (ρ = -0.42). LIMITATIONS The field of view of the measurement did not include the right hemisphere or parts of the frontal cortex. The sample size is moderate and the mothers were relatively highly educated, thus there may be some differences between the study sample and the general population. CONCLUSIONS Maternal pregnancy-related anxiety may affect child brain emotion processing development. Further research is needed to understand the functional and developmental significance of the findings.
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Affiliation(s)
- Ambika Maria
- University of Turku, Institute of Clinical Medicine, Turku Brain and Mind Center, FinnBrain Birth Cohort Study, Turku, Finland
| | - Ilkka Nissilä
- Aalto University, Department of Neuroscience and Biomedical Engineering, Finland.
| | - Shashank Shekhar
- University of Turku, Institute of Clinical Medicine, Turku Brain and Mind Center, FinnBrain Birth Cohort Study, Turku, Finland; University of Mississippi Medical Center, Department of Neurology, MS, USA
| | - Kalle Kotilahti
- Aalto University, Department of Neuroscience and Biomedical Engineering, Finland
| | - Jetro J Tuulari
- University of Turku, Institute of Clinical Medicine, Turku Brain and Mind Center, FinnBrain Birth Cohort Study, Turku, Finland; The Turku Collegium for Science and Medicine (TCSM); University of Oxford, Department of Psychiatry, Oxford, United Kingdom; University of Turku and Turku University Hospital, Department of Psychiatry, Turku, Finland
| | - Pauliina Hirvi
- Aalto University, Department of Neuroscience and Biomedical Engineering, Finland; Aalto University, Department of Mathematics and Systems Analysis, Finland
| | - Minna Huotilainen
- University of Turku, Institute of Clinical Medicine, Turku Brain and Mind Center, FinnBrain Birth Cohort Study, Turku, Finland; University of Helsinki, Faculty of Educational Sciences, CICERO Learning, Finland
| | - Juha Heiskala
- Helsinki University Central Hospital, Department of Clinical Neurophysiology, Finland
| | - Linnea Karlsson
- University of Turku, Institute of Clinical Medicine, Turku Brain and Mind Center, FinnBrain Birth Cohort Study, Turku, Finland; University of Turku and Turku University Hospital, Department of Child Psychiatry, Turku, Finland
| | - Hasse Karlsson
- University of Turku, Institute of Clinical Medicine, Turku Brain and Mind Center, FinnBrain Birth Cohort Study, Turku, Finland; University of Turku and Turku University Hospital, Department of Psychiatry, Turku, Finland
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11
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Leng H, Wang Y, Jhang DF, Chu TS, Tsao CH, Tsai CH, Giamundo S, Chen YY, Liao KW, Chuang CC, Ger TR, Chen LT, Liao LD. Characterization of a Fiber Bundle-Based Real-Time Ultrasound/Photoacoustic Imaging System and Its In Vivo Functional Imaging Applications. MICROMACHINES 2019; 10:mi10120820. [PMID: 31783545 PMCID: PMC6953120 DOI: 10.3390/mi10120820] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 11/19/2019] [Accepted: 11/22/2019] [Indexed: 12/17/2022]
Abstract
Photoacoustic (PA) imaging is an attractive technology for imaging biological tissues because it can capture both functional and structural information with satisfactory spatial resolution. Current commercially available PA imaging systems are limited by their bulky size or inflexible user interface. We present a new handheld real-time ultrasound/photoacoustic imaging system (HARP) consisting of a detachable, high-numerical-aperture (NA) fiber bundle-based illumination system integrated with an array-based ultrasound (US) transducer and a data acquisition platform. In this system, different PA probes can be used for different imaging applications by switching the transducers and the corresponding jackets to combine the fiber pads and transducer into a single probe. The intuitive user interface is a completely programmable MATLAB-based platform. In vitro phantom experiments were conducted to test the imaging performance of the developed PA system. Furthermore, we demonstrated (1) in vivo brain vasculature imaging, (2) in vivo imaging of real-time stimulus-evoked cortical hemodynamic changes during forepaw electrical stimulation, and (3) in vivo imaging of real-time cerebral pharmacokinetics in rats using the developed PA system. The overall purpose of this design concept for a customizable US/PA imaging system is to help overcome the diverse challenges faced by medical researchers performing both preclinical and clinical PA studies.
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Affiliation(s)
- He Leng
- Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, Zhunan Township, Miaoli County 35053, Taiwan; (H.L.); (D.-F.J.); (C.-H.T.)
| | - Yuhling Wang
- Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, Zhunan Township, Miaoli County 35053, Taiwan; (H.L.); (D.-F.J.); (C.-H.T.)
| | - De-Fu Jhang
- Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, Zhunan Township, Miaoli County 35053, Taiwan; (H.L.); (D.-F.J.); (C.-H.T.)
- Department of Biomedical Engineering, College of Engineering, Chung Yuan Christian University, Chung Li District, Taoyuan City 32023, Taiwan; (C.-C.C.)
| | - Tsung-Sheng Chu
- Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, Zhunan Township, Miaoli County 35053, Taiwan; (H.L.); (D.-F.J.); (C.-H.T.)
- Department of Biomedical Engineering, College of Engineering, Chung Yuan Christian University, Chung Li District, Taoyuan City 32023, Taiwan; (C.-C.C.)
| | - Chia-Hui Tsao
- Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, Zhunan Township, Miaoli County 35053, Taiwan; (H.L.); (D.-F.J.); (C.-H.T.)
| | - Chia-Hua Tsai
- Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, Zhunan Township, Miaoli County 35053, Taiwan; (H.L.); (D.-F.J.); (C.-H.T.)
| | | | - You-Yin Chen
- Department of Biomedical Engineering, National Yang Ming University, Taipei 112, Taiwan;
| | - Kuang-Wen Liao
- Department of Biological Science and Technology, National Chiao Tung University, Hsinchu 300, Taiwan;
| | - Chiung-Cheng Chuang
- Department of Biomedical Engineering, College of Engineering, Chung Yuan Christian University, Chung Li District, Taoyuan City 32023, Taiwan; (C.-C.C.)
| | - Tzong-Rong Ger
- Department of Biomedical Engineering, College of Engineering, Chung Yuan Christian University, Chung Li District, Taoyuan City 32023, Taiwan; (C.-C.C.)
| | - Li-Tzong Chen
- National Institute of Cancer Research, National Health Research Institutes, Zhunan Township, Miaoli County 35053, Taiwan;
| | - Lun-De Liao
- Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, Zhunan Township, Miaoli County 35053, Taiwan; (H.L.); (D.-F.J.); (C.-H.T.)
- Correspondence:
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12
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Dragojević T, Vidal Rosas EE, Hollmann JL, Culver JP, Justicia C, Durduran T. High-density speckle contrast optical tomography of cerebral blood flow response to functional stimuli in the rodent brain. NEUROPHOTONICS 2019; 6:045001. [PMID: 31620545 PMCID: PMC6782685 DOI: 10.1117/1.nph.6.4.045001] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 09/12/2019] [Indexed: 05/20/2023]
Abstract
Noninvasive, three-dimensional, and longitudinal imaging of cerebral blood flow (CBF) in small animal models and ultimately in humans has implications for fundamental research and clinical applications. It enables the study of phenomena such as brain development and learning and the effects of pathologies, with a clear vision for translation to humans. Speckle contrast optical tomography (SCOT) is an emerging optical method that aims to achieve this goal by directly measuring three-dimensional blood flow maps in deep tissue with a relatively inexpensive and simple system. High-density SCOT is developed to follow CBF changes in response to somatosensory cortex stimulation. Measurements are carried out through the intact skull on the rat brain. SCOT is able to follow individual trials in each brain hemisphere, where signal averaging resulted in comparable, cortical images to those of functional magnetic resonance images in spatial extent, location, and depth. Sham stimuli are utilized to demonstrate that the observed response is indeed due to local changes in the brain induced by forepaw stimulation. In developing and demonstrating the method, algorithms and analysis methods are developed. The results pave the way for longitudinal, nondestructive imaging in preclinical rodent models that can readily be translated to the human brain.
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Affiliation(s)
- Tanja Dragojević
- Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Barcelona, Spain
- Address all correspondence to Tanja Dragojević, E-mail:
| | - Ernesto E. Vidal Rosas
- Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Joseph L. Hollmann
- Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Joseph P. Culver
- Washington University, School of Medicine, Department of Radiology, St. Louis, Missouri, United States
- Washington University, Department of Physics, St. Louis, Missouri, United States
| | - Carles Justicia
- Institut d’Investigacions Biomèdiques de Barcelona, Consejo Superior de Investigaciones Científicas, Department of Brain Ischemia and Neurodegeneration, Barcelona, Spain
- Institut d’Investigacions Biomèdiques August Pi i Sunyer, Àrea de Neurociències, Barcelona, Spain
| | - Turgut Durduran
- Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats, Barcelona, Spain
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13
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Bauer AQ, Kraft AW, Baxter GA, Wright PW, Reisman MD, Bice AR, Park JJ, Bruchas MR, Snyder AZ, Lee JM, Culver JP. Effective Connectivity Measured Using Optogenetically Evoked Hemodynamic Signals Exhibits Topography Distinct from Resting State Functional Connectivity in the Mouse. Cereb Cortex 2018; 28:370-386. [PMID: 29136125 PMCID: PMC6057523 DOI: 10.1093/cercor/bhx298] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Indexed: 02/07/2023] Open
Abstract
Brain connectomics has expanded from histological assessment of axonal projection connectivity (APC) to encompass resting state functional connectivity (RS-FC). RS-FC analyses are efficient for whole-brain mapping, but attempts to explain aspects of RS-FC (e.g., interhemispheric RS-FC) based on APC have been only partially successful. Neuroimaging with hemoglobin alone lacks specificity for determining how activity in a population of cells contributes to RS-FC. Wide-field mapping of optogenetically defined connectivity could provide insights into the brain's structure-function relationship. We combined optogenetics with optical intrinsic signal imaging to create an efficient, optogenetic effective connectivity (Opto-EC) mapping assay. We examined EC patterns of excitatory neurons in awake, Thy1-ChR2 transgenic mice. These Thy1-based EC (Thy1-EC) patterns were evaluated against RS-FC over the cortex. Compared to RS-FC, Thy1-EC exhibited increased spatial specificity, reduced interhemispheric connectivity in regions with strong RS-FC, and appreciable connection strength asymmetry. Comparing the topography of Thy1-EC and RS-FC patterns to maps of APC revealed that Thy1-EC more closely resembled APC than did RS-FC. The more general method of Opto-EC mapping with hemoglobin can be determined for 100 sites in single animals in under an hour, and is amenable to other neuroimaging modalities. Opto-EC mapping represents a powerful strategy for examining evolving connectivity-related circuit plasticity.
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Affiliation(s)
- Adam Q Bauer
- Department of Radiology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Andrew W Kraft
- Department of Neurology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Grant A Baxter
- Department of Radiology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Patrick W Wright
- Department of Radiology, Washington University School of Medicine, Saint Louis, MO 63110, USA.,Department of Biomedical Engineering, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Matthew D Reisman
- Department of Physics, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Annie R Bice
- Department of Radiology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Jasmine J Park
- Department of Radiology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Michael R Bruchas
- Department of Biomedical Engineering, Washington University School of Medicine, Saint Louis, MO 63110, USA.,Department of Anesthesiology, Washington University School of Medicine, Saint Louis, MO 63110, USA.,Department of Neuroscience, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Abraham Z Snyder
- Department of Radiology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Jin-Moo Lee
- Department of Radiology, Washington University School of Medicine, Saint Louis, MO 63110, USA.,Department of Neurology, Washington University School of Medicine, Saint Louis, MO 63110, USA.,Department of Biomedical Engineering, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Joseph P Culver
- Department of Radiology, Washington University School of Medicine, Saint Louis, MO 63110, USA.,Department of Biomedical Engineering, Washington University School of Medicine, Saint Louis, MO 63110, USA.,Department of Physics, Washington University School of Medicine, Saint Louis, MO 63110, USA
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14
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Petridou N, Siero JCW. Laminar fMRI: What can the time domain tell us? Neuroimage 2017; 197:761-771. [PMID: 28736308 DOI: 10.1016/j.neuroimage.2017.07.040] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 07/06/2017] [Accepted: 07/19/2017] [Indexed: 01/30/2023] Open
Abstract
The rapid developments in functional MRI (fMRI) acquisition methods and hardware technologies in recent years, particularly at high field (≥7 T), have enabled unparalleled visualization of functional detail at a laminar or columnar level, bringing fMRI close to the intrinsic resolution of brain function. These advances highlight the potential of high resolution fMRI to be a valuable tool to study the fundamental processing performed in cortical micro-circuits, and their interactions such as feedforward and feedback processes. Notably, because fMRI measures neuronal activity via hemodynamics, the ultimate resolution it affords depends on the spatial specificity of hemodynamics to neuronal activity at a detailed spatial scale, and by the evolution of this specificity over time. Several laminar (≤1 mm spatial resolution) fMRI studies have examined spatial characteristics of the measured hemodynamic signals across cortical depth, in light of understanding or improving the spatial specificity of laminar fMRI. Few studies have examined temporal features of the hemodynamic response across cortical depth. Temporal features of the hemodynamic response offer an additional means to improve the specificity of fMRI, and could help target neuronal processes and neurovascular coupling relationships across laminae, for example by differences in the onset times of the response across cortical depth. In this review, we discuss factors that affect the timing of neuronal and hemodynamic responses across laminae, touching on the neuronal laminar organization, and focusing on the laminar vascular organization. We provide an overview of hemodynamics across the cortical vascular tree based on optical imaging studies, and review temporal aspects of hemodynamics that have been examined across cortical depth in high spatiotemporal resolution fMRI studies. Last, we discuss the limits and potential of high spatiotemporal resolution fMRI to study laminar neurovascular coupling and neuronal processes.
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Affiliation(s)
- Natalia Petridou
- Radiology, University Medical Centre Utrecht, Utrecht, The Netherlands.
| | - Jeroen C W Siero
- Radiology, University Medical Centre Utrecht, Utrecht, The Netherlands; Spinoza Centre for Neuroimaging, Amsterdam, The Netherlands
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15
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Sawosz P, Wojtkiewicz S, Kacprzak M, Weigl W, Borowska-Solonynko A, Krajewski P, Bejm K, Milej D, Ciszek B, Maniewski R, Liebert A. Human skull translucency: post mortem studies. BIOMEDICAL OPTICS EXPRESS 2016; 7:5010-5020. [PMID: 28018721 PMCID: PMC5175548 DOI: 10.1364/boe.7.005010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 10/27/2016] [Accepted: 10/28/2016] [Indexed: 05/10/2023]
Abstract
Measurements of optical translucency of human skulls were carried out. An incandescent light source and a CCD camera were used to measure the distribution of light transmitted through the skull in 10 subjects post-mortem. We noticed that intra-individual differences in optical translucency may be up to 100 times but inter-individual translucency differences across the skull reach 105 times. Based on the measurement results, a "theoretical" experiment was simulated. Monte-Carlo calculations were used in order to evaluate the influence of the differences in optical translucency of the skull on results of NIRS measurements. In these calculations a functional stimulation was done, in which the oxyhemoglobin and deoxyhemoglobin concentrations in the brain cortex change by 5μM and -5μM respectively. The maximal discrepancies between assumed hemoglobin concentration changes and hemoglobin concentration changes estimated with Monte-Carlo simulation may reach 50% depending of the translucency of the skull.
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Affiliation(s)
- P Sawosz
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| | - S Wojtkiewicz
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| | - M Kacprzak
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| | - W Weigl
- Department of Surgical Sciences/Anaesthesiology and Intensive Care, Uppsala University, Akademiska Hospital, Uppsala, Sweden
| | | | - P Krajewski
- Forensic Medicine Department, Medical University of Warsaw, Warsaw, Poland
| | - K Bejm
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| | - D Milej
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| | - B Ciszek
- Department of Descriptive and Clinical Anatomy, Medical University of Warsaw, Warsaw, Poland
| | - R Maniewski
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| | - A Liebert
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
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16
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Liao LD, Li ML, Lai HY, Chen YY, Thakor NV. Study of neurovascular coupling functions for transient focal cerebral ischemia in rats using electrocorticography functional photoacoustic microscopy (ECoG-fPAM). ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2015; 2013:1799-802. [PMID: 24110058 DOI: 10.1109/embc.2013.6609871] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Recently, the functional photoacoustic microscopy (fPAM) system has been proven to be a reliable imaging technique for measuring the total hemoglobin concentration (HbT), cerebral blood volume (CBV) and hemoglobin oxygen saturation (SO2) in single cerebral blood vessels of rats. In this study, we report for the first time the combination of electrocorticography (ECoG) recordings and fPAM (ECoG-fPAM) to investigate functional hemodynamic changes and neuro-vascular coupling in single cortical arterioles of rats with electrical forepaw stimulation after photothrombotic stroke. Because of the optical focusing nature of our fPAM system, photo-induced ischemic stroke targeting on single cortical arterioles can be easily conducted with simple adaptation. Functional cerebral HbT, CBV and SO2 changes associated with the induced stroke in selected arterioles from the anterior cerebral artery system were imaged with a 36 × 65-µm spatial resolution. The ECoG-fPAM system complements existing imaging techniques and has the potential to offer a favorable tool for explicitly studying cerebral hemodynamics and neuro-vascular coupling in small animal models of photo-induced ischemic stroke.
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17
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Abstract
Functional magnetic resonance imaging (fMRI) provides a unique view of the working human mind. The blood-oxygen-level-dependent (BOLD) signal, detected in fMRI, reflects changes in deoxyhemoglobin driven by localized changes in brain blood flow and blood oxygenation, which are coupled to underlying neuronal activity by a process termed neurovascular coupling. Over the past 10 years, a range of cellular mechanisms, including astrocytes, pericytes, and interneurons, have been proposed to play a role in functional neurovascular coupling. However, the field remains conflicted over the relative importance of each process, while key spatiotemporal features of BOLD response remain unexplained. Here, we review current candidate neurovascular coupling mechanisms and propose that previously overlooked involvement of the vascular endothelium may provide a more complete picture of how blood flow is controlled in the brain. We also explore the possibility and consequences of conditions in which neurovascular coupling may be altered, including during postnatal development, pathological states, and aging, noting relevance to both stimulus-evoked and resting-state fMRI studies.
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Affiliation(s)
- Elizabeth M C Hillman
- Departments of Biomedical Engineering and Radiology and the Kavli Institute for Brain Science, Columbia University, New York, NY 10027;
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18
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Meyer T, Sobottka SB, Kirsch M, Schackert G, Steinmeier R, Koch E, Morgenstern U. Intraoperative optical imaging of functional brain areas for improved image-guided surgery. ACTA ACUST UNITED AC 2014; 58:225-36. [PMID: 23729529 DOI: 10.1515/bmt-2012-0072] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Accepted: 04/03/2013] [Indexed: 11/15/2022]
Abstract
Intraoperative optical imaging of intrinsic signals can improve the localization of functional areas of the cortex. On the basis of a review of the current state of technology, a setup was developed and evaluated. The aim was to implement an easy-to-use and robust imaging setup that can be used in clinical routine with standard hardware equipment (surgical microscope, high-resolution camera, stimulator for peripheral nerve stimulation) and custom-made software for intraoperative and postoperative data analysis. Evaluation of different light sources (halogen, xenon) showed a sufficient temporal behavior of xenon light without using a stabilized power supply. Spatial binning (2×2) of the camera reduces temporal variations in the images by preserving a high spatial resolution. The setup was tested in eight patients. Images were acquired continuously for 9 min with alternating 30-s rest and 30-s stimulation conditions. Intraoperative measurement and visualization of high-resolution two-dimensional activity maps could be achieved in <15 min. The detected functional regions corresponded with anatomical and electrophysiological validation. The integration of optical imaging in clinical routine could successfully be achieved using standard hardware, which improves guidance for the surgeon during interventions near the eloquent areas of the brain.
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Affiliation(s)
- Tobias Meyer
- Institute of Biomedical Engineering, Faculty of Electrical Engineering and Information Technology, Dresden University of Technology, Dresden, Germany.
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19
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Liao LD, Orellana J, Liu YH, Lin YR, Vipin A, Thakor NV, Shen K, Wilder-Smith E. Imaging of temperature dependent hemodynamics in the rat sciatic nerve by functional photoacoustic microscopy. Biomed Eng Online 2013; 12:120. [PMID: 24245952 PMCID: PMC4225521 DOI: 10.1186/1475-925x-12-120] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Accepted: 10/09/2013] [Indexed: 02/08/2023] Open
Abstract
Background Vascular hemodynamics is central to the regulation of neuro-metabolism and plays important roles in peripheral nerves diseases and their prevention. However, at present there are only a few techniques capable of directly measuring peripheral nerve vascular hemodynamics. Method Here, we investigate the use of dark-field functional photoacoustic microscopy (fPAM) for intrinsic visualizing of the relative hemodynamics of the rat sciatic nerve in response to localized temperature modulation (i.e., cooling and rewarming). Results and conclusion Our main results show that the relative functional total hemoglobin concentration (HbT) is more significantly correlated with localized temperature changes than the hemoglobin oxygen saturation (SO2) changes in the sciatic nerve. Our study also indicates that the relative HbT changes are better markers of neuronal activation than SO2 during nerve temperature changes. Our results show that fPAM is a promising candidate for in vivo imaging of peripheral nerve hemodynamics without the use of contrast agents. Additionally, this technique may shed light on the neuroprotective effect of hypothermia on peripheral nerves by visualizing their intrinsic hemodynamics.
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Affiliation(s)
| | | | | | | | | | | | - Kaiquan Shen
- Singapore Institute for Neurotechnology (SINAPSE), National University of Singapore, 28 Medical Drive, #05-COR, Singapore 117456, Singapore.
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20
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Cutini S, Scarpa F, Scatturin P, Dell'Acqua R, Zorzi M. Number-space interactions in the human parietal cortex: Enlightening the SNARC effect with functional near-infrared spectroscopy. ACTA ACUST UNITED AC 2012; 24:444-51. [PMID: 23081883 DOI: 10.1093/cercor/bhs321] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Interactions between numbers and space have become a major issue in cognitive neuroscience, because they suggest that numerical representations might be deeply rooted in cortical networks that also subserve spatial cognition. The spatial-numerical association of response codes (SNARC) is the most robust and widely replicated demonstration of the link between numbers and space: in magnitude comparison or parity judgments, participants' reaction times to small numbers are faster with left than right effectors, whereas the converse is found for large numbers. However, despite the massive body of research on number-space interactions, the nature of the SNARC effect remains controversial and no study to date has identified its hemodynamic correlates. Using functional near-infrared spectroscopy, we found a hemodynamic signature of the SNARC effect in the bilateral intraparietal sulcus, a core region for numerical magnitude representation, and left angular gyrus (ANG), a region implicated in verbal number processing. Activation of intraparietal sulcus was also modulated by numerical distance. Our findings point to number semantics as cognitive locus of number-space interactions, thereby revealing the intrinsic spatial nature of numerical magnitude representation. Moreover, the involvement of left ANG is consistent with the mediating role of verbal/cultural factors in shaping interactions between numbers and space.
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Affiliation(s)
- Simone Cutini
- Department of General Psychology, University of Padova, Venice 35131, Italy
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21
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Szűcs D, Killikelly C, Cutini S. Event-related near-infrared spectroscopy detects conflict in the motor cortex in a Stroop task. Brain Res 2012; 1477:27-36. [DOI: 10.1016/j.brainres.2012.08.023] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Revised: 07/17/2012] [Accepted: 08/13/2012] [Indexed: 10/28/2022]
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Cheng R, Shang Y, Hayes D, Saha SP, Yu G. Noninvasive optical evaluation of spontaneous low frequency oscillations in cerebral hemodynamics. Neuroimage 2012; 62:1445-54. [DOI: 10.1016/j.neuroimage.2012.05.069] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2012] [Revised: 05/11/2012] [Accepted: 05/24/2012] [Indexed: 01/15/2023] Open
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Liao LD, Lin CT, Shih YYI, Lai HY, Zhao WT, Duong TQ, Chang JY, Chen YY, Li ML. Investigation of the cerebral hemodynamic response function in single blood vessels by functional photoacoustic microscopy. JOURNAL OF BIOMEDICAL OPTICS 2012; 17:061210. [PMID: 22734740 PMCID: PMC4023648 DOI: 10.1117/1.jbo.17.6.061210] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Revised: 12/22/2011] [Accepted: 01/16/2012] [Indexed: 05/29/2023]
Abstract
The specificity of the hemodynamic response function (HRF) is determined spatially by the vascular architecture and temporally by the evolution of hemodynamic changes. Here, we used functional photoacoustic microscopy (fPAM) to investigate single cerebral blood vessels of rats after left forepaw stimulation. In this system, we analyzed the spatiotemporal evolution of the HRFs of the total hemoglobin concentration (HbT), cerebral blood volume (CBV), and hemoglobin oxygen saturation (SO(2)). Changes in specific cerebral vessels corresponding to various electrical stimulation intensities and durations were bilaterally imaged with 36 × 65-μm(2) spatial resolution. Stimulation intensities of 1, 2, 6, and 10 mA were applied for periods of 5 or 15 s. Our results show that the relative functional changes in HbT, CBV, and SO(2) are highly dependent not only on the intensity of the stimulation, but also on its duration. Additionally, the duration of the stimulation has a strong influence on the spatiotemporal characteristics of the HRF as shorter stimuli elicit responses only in the local vasculature (smaller arterioles), whereas longer stimuli lead to greater vascular supply and drainage. This study suggests that the current fPAM system is reliable for studying relative cerebral hemodynamic changes, as well as for offering new insights into the dynamics of functional cerebral hemodynamic changes in small animals.
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Affiliation(s)
- Lun-De Liao
- National Chiao Tung University, Department of Electrical Engineering, Hsinchu, Taiwan
- National Chiao Tung University, Brain Research Center, Hsinchu, Taiwan
| | - Chin-Teng Lin
- National Chiao Tung University, Department of Electrical Engineering, Hsinchu, Taiwan
- National Chiao Tung University, Brain Research Center, Hsinchu, Taiwan
| | - Yen-Yu I. Shih
- University of Texas Health Science Center at San Antonio, Research Imaging Institute, San Antonio, Texas
| | - Hsin-Yi Lai
- National Chiao Tung University, Department of Electrical Engineering, Hsinchu, Taiwan
| | - Wan-Ting Zhao
- National Taiwan University, Institute of Zoology, Taipei, Taiwan
| | - Timothy Q. Duong
- University of Texas Health Science Center at San Antonio, Research Imaging Institute, San Antonio, Texas
| | - Jyh-Yeong Chang
- National Chiao Tung University, Department of Electrical Engineering, Hsinchu, Taiwan
| | - You-Yin Chen
- National Chiao Tung University, Department of Electrical Engineering, Hsinchu, Taiwan
- National Yang Ming University, Department of Biomedical Engineering, Taipei, Taiwan
| | - Meng-Lin Li
- National Tsing Hua University, Department of Electrical Engineering, Hsinchu, Taiwan
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Liao LD, Lin CT, Shih YYI, Duong TQ, Lai HY, Wang PH, Wu R, Tsang S, Chang JY, Li ML, Chen YY. Transcranial imaging of functional cerebral hemodynamic changes in single blood vessels using in vivo photoacoustic microscopy. J Cereb Blood Flow Metab 2012; 32:938-51. [PMID: 22472612 PMCID: PMC3367230 DOI: 10.1038/jcbfm.2012.42] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Optical imaging of changes in total hemoglobin concentration (HbT), cerebral blood volume (CBV), and hemoglobin oxygen saturation (SO(2)) provides a means to investigate brain hemodynamic regulation. However, high-resolution transcranial imaging remains challenging. In this study, we applied a novel functional photoacoustic microscopy technique to probe the responses of single cortical vessels to left forepaw electrical stimulation in mice with intact skulls. Functional changes in HbT, CBV, and SO(2) in the superior sagittal sinus and different-sized arterioles from the anterior cerebral artery system were bilaterally imaged with unambiguous 36 × 65-μm(2) spatial resolution. In addition, an early decrease of SO(2) in single blood vessels during activation (i.e., 'the initial dip') was observed. Our results indicate that the initial dip occurred specifically in small arterioles of activated regions but not in large veins. This technique complements other existing imaging approaches for the investigation of the hemodynamic responses in single cerebral blood vessels.
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Affiliation(s)
- Lun-De Liao
- Department of Electrical Engineering, National Chiao Tung University, Hsinchu, Taiwan
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25
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Dehaes M, Kazemi K, Pélégrini-Issac M, Grebe R, Benali H, Wallois F. Quantitative effect of the neonatal fontanel on synthetic near infrared spectroscopy measurements. Hum Brain Mapp 2011; 34:878-89. [PMID: 22109808 DOI: 10.1002/hbm.21483] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Revised: 09/05/2011] [Accepted: 09/06/2011] [Indexed: 01/07/2023] Open
Abstract
Near infrared spectroscopy (NIRS) is a functional imaging technique allowing measurement of local cerebral oxygenation. This modality is particularly adapted to critically ill neonates, as it can be used at the bedside and is a suitable and noninvasive tool for carrying out longitudinal studies. However, NIRS is sensitive to the imaged medium and consequently to the optical properties of biological tissues in which photons propagate. In this study, the effect of the neonatal fontanel was investigated by predicting photon propagation using a probabilistic Monte Carlo approach. Two anatomical newborn head models were created from computed tomography and magnetic resonance images: (1) a realistic model including the fontanel tissue and (2) a model in which the fontanel was replaced by skull tissue. Quantitative change in absorption due to simulated activation was compared for the two models for specific regions of activation and optical arrays simulated in the temporal area. A correction factor was computed to quantify the effect of the fontanel and defined by the ratio between the true and recovered change. The results show that recovered changes in absorption were more precise when determined with the anatomical model including the fontanel. The results suggest that the fontanel should be taken into account in quantification of NIRS responses to avoid misinterpretation in experiments involving temporal areas, such as language or auditory studies.
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Affiliation(s)
- Mathieu Dehaes
- GRAMFC, UPJV, EA 4293, Laboratoire de Neurophysiologie, Amiens, France.
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26
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Gagnon L, Yücel MA, Dehaes M, Cooper RJ, Perdue KL, Selb J, Huppert TJ, Hoge RD, Boas DA. Quantification of the cortical contribution to the NIRS signal over the motor cortex using concurrent NIRS-fMRI measurements. Neuroimage 2011; 59:3933-40. [PMID: 22036999 DOI: 10.1016/j.neuroimage.2011.10.054] [Citation(s) in RCA: 141] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Revised: 10/04/2011] [Accepted: 10/17/2011] [Indexed: 11/19/2022] Open
Abstract
Near-Infrared Spectroscopy (NIRS) measures the functional hemodynamic response occurring at the surface of the cortex. Large pial veins are located above the surface of the cerebral cortex. Following activation, these veins exhibit oxygenation changes but their volume likely stays constant. The back-reflection geometry of the NIRS measurement renders the signal very sensitive to these superficial pial veins. As such, the measured NIRS signal contains contributions from both the cortical region as well as the pial vasculature. In this work, the cortical contribution to the NIRS signal was investigated using (1) Monte Carlo simulations over a realistic geometry constructed from anatomical and vascular MRI and (2) multimodal NIRS-BOLD recordings during motor stimulation. A good agreement was found between the simulations and the modeling analysis of in vivo measurements. Our results suggest that the cortical contribution to the deoxyhemoglobin signal change (ΔHbR) is equal to 16-22% of the cortical contribution to the total hemoglobin signal change (ΔHbT). Similarly, the cortical contribution of the oxyhemoglobin signal change (ΔHbO) is equal to 73-79% of the cortical contribution to the ΔHbT signal. These results suggest that ΔHbT is far less sensitive to pial vein contamination and therefore, it is likely that the ΔHbT signal provides better spatial specificity and should be used instead of ΔHbO or ΔHbR to map cerebral activity with NIRS. While different stimuli will result in different pial vein contributions, our finger tapping results do reveal the importance of considering the pial contribution.
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Affiliation(s)
- Louis Gagnon
- Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA.
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27
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van Raaij ME, Lindvere L, Dorr A, He J, Sahota B, Foster FS, Stefanovic B. Functional micro-ultrasound imaging of rodent cerebral hemodynamics. Neuroimage 2011; 58:100-8. [PMID: 21704715 DOI: 10.1016/j.neuroimage.2011.05.088] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2011] [Revised: 04/11/2011] [Accepted: 05/23/2011] [Indexed: 11/16/2022] Open
Abstract
Healthy cerebral microcirculation is crucial to neuronal functioning. We present a new method to investigate microvascular hemodynamics in living rodent brain through a focal cranial window based on high-frequency ultrasound imaging. The method has a temporal resolution of 40ms, and a 100μm in-plane and 600μm through-plane spatial resolution. We use a commercially available high-frequency ultrasound imaging system to quantify changes in the relative cerebral blood volume (CBV) by measuring the scattered signal intensity from an ultrasound contrast agent circulating in the vasculature. Generalized linear model analysis is then used to produce effect size and significance maps of changes in cerebral blood volume upon electrical stimulation of the forepaw. We observe larger CBV increases in the forelimb representation of the primary somatosensory cortex than in the deep gray matter with stimuli as short as 2s (5.1 ± 1.3% vs. 3.3 ± 0.6%). We also investigate the temporal evolution of the blood volume changes in cortical and subcortical gray matter, pial vessels and subcortical major vessels, and show shorter response onset times in the parenchymal regions than in the neighboring large vessels (1.6 ± 1.0s vs. 2.6 ± 1.3s in the cortex for a 10 second stimulus protocol). This method, which we termed functional micro-ultrasound imaging or fMUS, is a novel, highly accessible, and cost-effective way of imaging rodent brain microvascular topology and hemodynamics in vivo at 100micron resolution over a 1-by-1cm field of view with 10s-100s frames per second that opens up a new set of questions regarding brain function in preclinical models of health and disease.
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Affiliation(s)
- Martijn E van Raaij
- Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, ON, Canada.
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28
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Shang Y, Cheng R, Dong L, Ryan SJ, Saha SP, Yu G. Cerebral monitoring during carotid endarterectomy using near-infrared diffuse optical spectroscopies and electroencephalogram. Phys Med Biol 2011; 56:3015-32. [PMID: 21508444 DOI: 10.1088/0031-9155/56/10/008] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Intraoperative monitoring of cerebral hemodynamics during carotid endarterectomy (CEA) provides essential information for detecting cerebral hypoperfusion induced by temporary internal carotid artery (ICA) clamping and post-CEA hyperperfusion syndrome. This study tests the feasibility and sensitivity of a novel dual-wavelength near-infrared diffuse correlation spectroscopy technique in detecting cerebral blood flow (CBF) and cerebral oxygenation in patients undergoing CEA. Two fiber-optic probes were taped on both sides of the forehead for cerebral hemodynamic measurements, and the instantaneous decreases in CBF and electroencephalogram (EEG) alpha-band power during ICA clamping were compared to test the measurement sensitivities of the two techniques. The ICA clamps resulted in significant CBF decreases (-24.7 ± 7.3%) accompanied with cerebral deoxygenation at the surgical sides (n = 12). The post-CEA CBF were significantly higher (+43.2 ± 16.9%) than the pre-CEA CBF. The CBF responses to ICA clamping were significantly faster, larger and more sensitive than EEG responses. Simultaneous monitoring of CBF, cerebral oxygenation and EEG power provides a comprehensive evaluation of cerebral physiological status, thus showing potential for the adoption of acute interventions (e.g., shunting, medications) during CEA to reduce the risks of severe cerebral ischemia and cerebral hyperperfusion syndrome.
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Affiliation(s)
- Yu Shang
- Center for Biomedical Engineering, University of Kentucky, KY, USA
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29
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Dehaes M, Gagnon L, Lesage F, Pélégrini-Issac M, Vignaud A, Valabrègue R, Grebe R, Wallois F, Benali H. Quantitative investigation of the effect of the extra-cerebral vasculature in diffuse optical imaging: a simulation study. BIOMEDICAL OPTICS EXPRESS 2011; 2:680-95. [PMID: 21412472 PMCID: PMC3047372 DOI: 10.1364/boe.2.000680] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2010] [Revised: 02/10/2011] [Accepted: 02/10/2011] [Indexed: 05/25/2023]
Abstract
Diffuse optical imaging (DOI) is a non invasive technique allowing the recovery of hemodynamic changes in the brain. Due to the diffusive nature of photon propagation in turbid media and the fact that cerebral tissues are located around 1.5 cm under the adult human scalp, DOI measurements are subject to partial volume errors. DOI measurements are also sensitive to large pial vessels because oxygenated and deoxygenated hemoglobin are the dominant chromophores in the near infrared window. In this study, the effect of the extra-cerebral vasculature in proximity of the sagittal sinus was investigated for its impact on DOI measurements simulated over the human adult visual cortex. Numerical Monte Carlo simulations were performed on two specific models of the human head derived from magnetic resonance imaging (MRI) scans. The first model included the extra-cerebral vasculature in which constant hemoglobin concentrations were assumed while the second did not. The screening effect of the vasculature was quantified by comparing recovered hemoglobin changes from each model for different optical arrays and regions of activation. A correction factor accounting for the difference between the recovered and the simulated hemoglobin changes was computed in each case. The results show that changes in hemoglobin concentration are better estimated when the extra-cerebral vasculature is modeled and the correction factors obtained in this case were at least 1.4-fold lower. The effect of the vasculature was also examined in a high-density diffuse optical tomography configuration. In this case, the difference between changes in hemoglobin concentration recovered with each model was reduced down to 10%.
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Affiliation(s)
- Mathieu Dehaes
- Inserm, UPMC Univ Paris 06, UMR-S 678, LIF & LINeM, Paris, France
- Université de Picardie Jules Verne, GRAMFC, EA 4293, Amiens, France
- Present address: Division of Newborn Medicine, Department of Medicine, Children's Hospital Boston and Harvard Medical School, 300 Longwood Avenue, Boston, Massachusetts 02115, phone: +1-857-218-5142, fax: +1-617-730-4671, USA
| | - Louis Gagnon
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts 02129, USA
- Harvard-MIT Division of Health Sciences and Technology, Cambridge, Massachusetts USA
| | - Frédéric Lesage
- École Polytechnique de Montréal, Département de génie électrique, Montréal, Canada
| | | | | | | | - Reinhard Grebe
- Université de Picardie Jules Verne, GRAMFC, EA 4293, Amiens, France
| | - Fabrice Wallois
- Université de Picardie Jules Verne, GRAMFC, EA 4293, Amiens, France
| | - Habib Benali
- Inserm, UPMC Univ Paris 06, UMR-S 678, LIF & LINeM, Paris, France
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30
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White BR, Bauer AQ, Snyder AZ, Schlaggar BL, Lee JM, Culver JP. Imaging of functional connectivity in the mouse brain. PLoS One 2011; 6:e16322. [PMID: 21283729 PMCID: PMC3024435 DOI: 10.1371/journal.pone.0016322] [Citation(s) in RCA: 168] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Accepted: 12/11/2010] [Indexed: 11/19/2022] Open
Abstract
Functional neuroimaging (e.g., with fMRI) has been difficult to perform in mice, making it challenging to translate between human fMRI studies and molecular and genetic mechanisms. A method to easily perform large-scale functional neuroimaging in mice would enable the discovery of functional correlates of genetic manipulations and bridge with mouse models of disease. To satisfy this need, we combined resting-state functional connectivity mapping with optical intrinsic signal imaging (fcOIS). We demonstrate functional connectivity in mice through highly detailed fcOIS mapping of resting-state networks across most of the cerebral cortex. Synthesis of multiple network connectivity patterns through iterative parcellation and clustering provides a comprehensive map of the functional neuroarchitecture and demonstrates identification of the major functional regions of the mouse cerebral cortex. The method relies on simple and relatively inexpensive camera-based equipment, does not require exogenous contrast agents and involves only reflection of the scalp (the skull remains intact) making it minimally invasive. In principle, fcOIS allows new paradigms linking human neuroscience with the power of molecular/genetic manipulations in mouse models.
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Affiliation(s)
- Brian R. White
- Department of Physics, Washington University, St. Louis, Missouri, United States of America
- Department of Radiology, Washington University, St. Louis, Missouri, United States of America
| | - Adam Q. Bauer
- Department of Radiology, Washington University, St. Louis, Missouri, United States of America
| | - Abraham Z. Snyder
- Department of Radiology, Washington University, St. Louis, Missouri, United States of America
- Department of Neurology, Washington University, St. Louis, Missouri, United States of America
| | - Bradley L. Schlaggar
- Department of Radiology, Washington University, St. Louis, Missouri, United States of America
- Department of Neurology, Washington University, St. Louis, Missouri, United States of America
- Department of Anatomy and Neurobiology, Washington University, St. Louis, Missouri, United States of America
- Department of Pediatrics, Washington University, St. Louis, Missouri, United States of America
| | - Jin-Moo Lee
- Department of Neurology, Washington University, St. Louis, Missouri, United States of America
| | - Joseph P. Culver
- Department of Physics, Washington University, St. Louis, Missouri, United States of America
- Department of Radiology, Washington University, St. Louis, Missouri, United States of America
- Department of Biomedical Engineering, Washington University, St. Louis, Missouri, United States of America
- * E-mail:
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31
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Cutini S, Scarpa F, Scatturin P, Jolicœur P, Pluchino P, Zorzi M, Dell'Acqua R. A hemodynamic correlate of lateralized visual short-term memories. Neuropsychologia 2010; 49:1611-21. [PMID: 21163274 DOI: 10.1016/j.neuropsychologia.2010.12.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2010] [Revised: 11/27/2010] [Accepted: 12/06/2010] [Indexed: 11/30/2022]
Abstract
Neuroimaging studies attempting to isolate the neural substrate of visual short-term memory in humans have concentrated on the behavior of neurons populating the posterior part of the parietal cortex as a possible source of visual short-term memory capacity limits. Using a standard change-detection task, fMRI studies have shown that maintenance of bilaterally encoded objects elicited bilateral increases of hemodynamic activation in the intra-parietal and intra-occipital sulci (IPS-IOS) proportional to the number of objects retained in visual short-term memory. We used a spatially cued variant of the change-detection task to record hemodynamic responses to unilaterally encoded objects using functional near-infrared spectroscopy (fNIRS). Electrophysiological studies that employed this task have shown that maintenance of unilaterally encoded objects elicited posterior unilateral (contralateral) increase in event-related negativity proportional to the number of objects retained in visual short-term memory. We therefore examined whether contralateral increases in oxy-hemoglobin concentration correlated with the number of retained objects. Contrary to the idea that bilateral increases in BOLD responses and unilateral increases in event-related negativity may be different reflections of the same underlying neural/functional processing, memory-related increases in oxy-hemoglobin concentration were found bilaterally even when objects had to be encoded unilaterally. The present findings suggest that EEG and fMRI/fNIRS techniques reveal distinct neural signatures of the mechanisms supporting visual short-term memory.
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Affiliation(s)
- Simone Cutini
- Department of Developmental Psychology, University of Padova, Padova, Italy
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32
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Scarpa F, Cutini S, Scatturin P, Dell'Acqua R, Sparacino G. Bayesian filtering of human brain hemodynamic activity elicited by visual short-term maintenance recorded through functional near-infrared spectroscopy (fNIRS). OPTICS EXPRESS 2010; 18:26550-26568. [PMID: 21165006 DOI: 10.1364/oe.18.026550] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Functional near-infrared spectroscopy (fNIRS) is a neuroimaging technique that measures changes in oxy-hemoglobin (ΔHbO) and deoxy-hemoglobin (ΔHbR) concentration associated with brain activity. The signal acquired with fNIRS is naturally affected by disturbances engendering from ongoing physiological activity (e.g., cardiac, respiratory, Mayer wave) and random measurement noise. Despite its several drawbacks, the so-called conventional averaging (CA) is still widely used to estimate the hemodynamic response function (HRF) from noisy signal. One such drawback is related to the number of trials necessary to derive stable HRF functions adopting the CA approach, which must be substantial (N >> 50). In this work, a pre-processing procedure to remove artifacts followed by the application of a non-parametric Bayesian approach is proposed that capitalizes on a priori available knowledge about HRF and noise. Results with the proposed Bayesian approach were compared with CA and with a straightforward band-pass filtering approach. On simulated data, a five times lower estimation error on HRF was obtained with respect to that obtained by CA, and 2.5 times lower than that obtained by band pass filtering. On real data, the improvement achieved by the present method was attested by an increase in the contrast to noise ratio (CNR) and by a reduced variability in single trial estimation. An application of the present Bayesian approach is illustrated that was optimized to monitor changes in hemodynamic activity reflecting variations in visual short-term memory load in humans, which are notoriously hard to detect using functional magnetic resonance imaging (fMRI). In particular, statistical analyses of HRFs recorded during a memory task established with high reliability the crucial role of the intraparietal sulcus and the intra-occipital sulcus in posterior areas of the human brain in visual short-term memory maintenance.
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Affiliation(s)
- F Scarpa
- Department of Developmental Psychology, University of Padova, Via Venezia 8, Padova 35131, Italy.
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33
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Chen BR, Bouchard MB, McCaslin AFH, Burgess SA, Hillman EMC. High-speed vascular dynamics of the hemodynamic response. Neuroimage 2010; 54:1021-30. [PMID: 20858545 DOI: 10.1016/j.neuroimage.2010.09.036] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2010] [Revised: 09/03/2010] [Accepted: 09/14/2010] [Indexed: 11/20/2022] Open
Abstract
While a range of cellular mechanisms have been proposed to underlie control of neurovascular coupling, a comprehensive, reconciliatory model has yet to be determined. To fit with such a model, it is essential that candidate mechanisms exhibit reaction times, spatial ranges, and speeds of propagation that are consistent with the vascular manifestations of the 'hemodynamic response'. Understanding these vascular dynamics is therefore a critical step towards developing a robust model of neurovascular coupling. In this study, we utilize high-speed optical imaging of exposed rodent somatosensory cortex to explore and characterize the spatiotemporal dynamics of surface vessels during functional hyperemia. Our high-speed, high-resolution optical imaging approach allows us to study the hemodynamic response independently in individual vessels, and in discrete regions of the parenchyma with enough resolution to precisely characterize subtle spatial and temporal features of the response. Specifically, we explore when and where the first hemodynamic changes occur in response to stimuli, the direction and speed at which these changes propagate in arterioles and regions of the parenchyma, and the relative timing at which each of these compartments returns to its original baseline state. From these results, we are able to conclude that the hemodynamic response appears to initiate in the parenchyma and then spreads rapidly to surface arterioles. Following the initial onset we find evidence that the response spreads spatially outwards via the dilation of targeted arterioles. This propagation of vasodilation is independent of the direction of blood flow within each arteriole. We also find evidence of a decay phase that acts with a more uniform spatial dependence, rather than along targeted vessels, causing the periphery of the responding region to return to baseline first. We hypothesize that different underlying cellular mechanisms/signaling pathways are responsible for the response initiation and the response decay. Our results advance the fundamental understanding of the hemodynamic response, as well as our ability to evaluate potential cellular mechanisms for their involvement in neurovascular coupling.
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Affiliation(s)
- Brenda R Chen
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA.
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34
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Mesquita RC, Franceschini MA, Boas DA. Resting state functional connectivity of the whole head with near-infrared spectroscopy. BIOMEDICAL OPTICS EXPRESS 2010; 1:324-336. [PMID: 21258470 PMCID: PMC3005169 DOI: 10.1364/boe.1.000324] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2010] [Revised: 06/24/2010] [Accepted: 07/27/2010] [Indexed: 05/18/2023]
Abstract
Resting state connectivity aims to identify spontaneous cerebral hemodynamic fluctuations that reflect neuronal activity at rest. In this study, we investigated the spatial-temporal correlation of hemoglobin concentration signals over the whole head during the resting state. By choosing a source-detector pair as a seed, we calculated the correlation value between its time course and the time course of all other source-detector combinations, and projected them onto a topographic map. In all subjects, we found robust spatial interactions in agreement with previous fMRI and NIRS findings. Strong correlations between the two opposite hemispheres were seen for both sensorimotor and visual cortices. Correlations in the prefrontal cortex were more heterogeneous and dependent on the hemodynamic contrast. HbT provided robust, well defined maps, suggesting that this contrast may be used to better localize functional connectivity. The effects of global systemic physiology were also investigated, particularly low frequency blood pressure oscillations which give rise to broad regions of high correlation and mislead interpretation of the results. These results confirm the feasibility of using functional connectivity with optical methods during the resting state, and validate its use to investigate cortical interactions across the whole head.
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Affiliation(s)
- Rickson C. Mesquita
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital,
Charlestown, MA 02129, USA
- Department of Physics & Astronomy, University of Pennsylvania, 209 South 33rd St., Philadelphia, PA 19104, USA
| | - Maria A. Franceschini
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital,
Charlestown, MA 02129, USA
| | - David A. Boas
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital,
Charlestown, MA 02129, USA
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35
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Liao SM, Gregg NM, White BR, Zeff BW, Bjerkaas KA, Inder TE, Culver JP. Neonatal hemodynamic response to visual cortex activity: high-density near-infrared spectroscopy study. JOURNAL OF BIOMEDICAL OPTICS 2010; 15:026010. [PMID: 20459255 PMCID: PMC2874048 DOI: 10.1117/1.3369809] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2009] [Revised: 01/14/2010] [Accepted: 01/26/2010] [Indexed: 05/18/2023]
Abstract
The neurodevelopmental outcome of neonatal intensive care unit (NICU) infants is a major clinical concern with many infants displaying neurobehavioral deficits in childhood. Functional neuroimaging may provide early recognition of neural deficits in high-risk infants. Near-infrared spectroscopy (NIRS) has the advantage of providing functional neuroimaging in infants at the bedside. However, limitations in traditional NIRS have included contamination from superficial vascular dynamics in the scalp. Furthermore, controversy exists over the nature of normal vascular, responses in infants. To address these issues, we extend the use of novel high-density NIRS arrays with multiple source-detector distances and a superficial signal regression technique to infants. Evaluations of healthy term-born infants within the first three days of life are performed without sedation using a visual stimulus. We find that the regression technique significantly improves brain activation signal quality. Furthermore, in six out of eight infants, both oxy- and total hemoglobin increases while deoxyhemoglobin decreases, suggesting that, at term, the neurovascular coupling in the visual cortex is similar to that found in healthy adults. These results demonstrate the feasibility of using high-density NIRS arrays in infants to improve signal quality through superficial signal regression, and provide a foundation for further development of high-density NIRS as a clinical tool.
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Affiliation(s)
- Steve M Liao
- Washington University School of Medicine, Department of Pediatrics and Department of Neurology and Department of Radiology, St. Louis, Missouri 63110, USA
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36
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Spatiotemporal precision and hemodynamic mechanism of optical point spreads in alert primates. Proc Natl Acad Sci U S A 2009; 106:18390-5. [PMID: 19828443 DOI: 10.1073/pnas.0905509106] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In functional brain imaging there is controversy over which hemodynamic signal best represents neural activity. Intrinsic signal optical imaging (ISOI) suggests that the best signal is the early darkening observed at wavelengths absorbed preferentially by deoxyhemoglobin (HbR). It is assumed that this darkening or "initial dip" reports local conversion of oxyhemoglobin (HbO) to HbR, i.e., oxygen consumption caused by local neural activity, thus giving the most specific measure of such activity. The blood volume signal, by contrast, is believed to be more delayed and less specific. Here, we used multiwavelength ISOI to simultaneously map oxygenation and blood volume [i.e., total hemoglobin (HbT)] in primary visual cortex (V1) of the alert macaque. We found that the hemodynamic "point spread," i.e., impulse response to a minimal visual stimulus, was as rapid and retinotopically specific when imaged by using blood volume as when using the initial dip. Quantitative separation of the imaged signal into HbR, HbO, and HbT showed, moreover, that the initial dip was dominated by a fast local increase in HbT, with no increase in HbR. We found only a delayed HbR decrease that was broader in retinotopic spread than HbO or HbT. Further, we show that the multiphasic time course of typical ISOI signals and the strength of the initial dip may reflect the temporal interplay of monophasic HbO, HbR, and HbT signals. Characterizing the hemodynamic response is important for understanding neurovascular coupling and elucidating the physiological basis of imaging techniques such as fMRI.
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37
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Haemodynamic changes during seizure-like activity in a neonate: A simultaneous AC EEG-SPIR and high-resolution DC EEG recording. Neurophysiol Clin 2009; 39:217-27. [DOI: 10.1016/j.neucli.2009.08.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2009] [Revised: 07/09/2009] [Accepted: 08/10/2009] [Indexed: 11/23/2022] Open
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38
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White BR, Snyder AZ, Cohen AL, Petersen SE, Raich-le ME, Schlaggar BL, Culver JP. Resting-state functional connectivity in the human brain revealed with diffuse optical tomography. Neuroimage 2009; 47:148-56. [PMID: 19344773 PMCID: PMC2699418 DOI: 10.1016/j.neuroimage.2009.03.058] [Citation(s) in RCA: 195] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2009] [Revised: 03/12/2009] [Accepted: 03/20/2009] [Indexed: 11/21/2022] Open
Abstract
Mapping resting-state networks allows insight into the brain's functional architecture and physiology and has rapidly become important in contemporary neuroscience research. Diffuse optical tomography (DOT) is an emerging functional neuroimaging technique with the advantages, relative to functional magnetic resonance imaging (fMRI), of portability and the ability to simultaneously measure both oxy- and deoxyhemoglobin. Previous optical studies have evaluated the temporal features of spontaneous resting brain signals. Herein, we develop techniques for spatially mapping functional connectivity with DOT (fc-DOT). Simultaneous imaging over the motor and visual cortices yielded robust correlation maps reproducing the expected functional neural architecture. The localization of the maps was confirmed with task-response studies and with subject-matched fc-MRI. These fc-DOT methods provide a task-less approach to mapping brain function in populations that were previously difficult to research. Our advances may permit new studies of early childhood development and of unconscious patients. In addition, the comprehensive hemoglobin contrasts of fc-DOT enable innovative studies of the biophysical origin of the functional connectivity signal.
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Affiliation(s)
- Brian R. White
- Department of Radiology, Washington University, St. Louis, MO 63110
- Department of Physics, Washington University, St. Louis, MO 63110
| | - Abraham Z. Snyder
- Department of Radiology, Washington University, St. Louis, MO 63110
- Department of Neurology, Washington University, St. Louis, MO 63110
| | | | - Steven E. Petersen
- Department of Radiology, Washington University, St. Louis, MO 63110
- Department of Neurology, Washington University, St. Louis, MO 63110
- Department of Anatomy and Neurobiology, Washington University, St. Louis, MO 63110
- Department of Psychology, Washington University, St. Louis, MO 63110
| | - Marcus E. Raich-le
- Department of Radiology, Washington University, St. Louis, MO 63110
- Department of Neurology, Washington University, St. Louis, MO 63110
- Department of Anatomy and Neurobiology, Washington University, St. Louis, MO 63110
- Department of Biomedical Engineering, Washington University, St. Louis, MO 63110
| | - Bradley L. Schlaggar
- Department of Radiology, Washington University, St. Louis, MO 63110
- Department of Neurology, Washington University, St. Louis, MO 63110
- Department of Anatomy and Neurobiology, Washington University, St. Louis, MO 63110
- Department of Pediatrics, Washington University, St. Louis, MO 63110
| | - Joseph P. Culver
- Department of Radiology, Washington University, St. Louis, MO 63110
- Department of Physics, Washington University, St. Louis, MO 63110
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39
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Ma H, Zhao M, Suh M, Schwartz TH. Hemodynamic surrogates for excitatory membrane potential change during interictal epileptiform events in rat neocortex. J Neurophysiol 2009; 101:2550-62. [PMID: 19244357 DOI: 10.1152/jn.90694.2008] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Hemodynamic changes in the brain are often used as surrogates for epileptic neuronal activity in both the laboratory and the clinic (e.g., intrinsic signal, functional magnetic resonance imaging and single-photon emission computed tomography) in spite of the fact that perfusion-based signals have been shown to overestimate the population of spiking neurons. In addition, mechanisms of neurovascular coupling that apply during normal cortical processing may not be relevant in pathological circumstances such as epilepsy. For these reasons, we investigated the spatiotemporal dynamics of epileptic neurovascular coupling using voltage-sensitive dyes (VSDs) to generate spatial maps of excitatory membrane activity and intrinsic optical spectroscopy (IOS) to measure deoxy-hemoglobin and total hemoglobin, i.e., cerebral blood volume (CBV), in vivo during interictal spikes in rat neocortex to examine their spatiotemporal correlations. We hypothesized that the IOS signal would correlate spatially with subthreshold excitatory activity, which involves a larger area of cortex than suprathreshold neuronal spiking. However, we found that both perfusion and oximetric signals spatially overshot the extent of the excitatory VSD signal by approximately 2x. Nevertheless, a high correlation could be found at specific time points in the evolution and dissolution of the hemodynamic signals. The increase in deoxy-hemoglobin reached the highest correlation with the excitatory VSD signal earlier than CBV signals although CBV signals correlated equally well at certain time points. The amplitude of the hemodynamic signals had a linear correlation with the amplitude of the VSD signals except for small nonlinearities in the very center of the focus and in the periphery of the surround, indicating a tight spatial coupling. Our data suggest that hemodynamic signals can accurately define the spatial extent of excitatory interictal epileptiform subthreshold membrane activity at specific time points in their evolution.
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Affiliation(s)
- Hongtao Ma
- Dept. of Neurological Surgery, Weill Medical College of Cornell University, New York Presbyterian Hospital, New York, NY 10065, USA.
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40
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Multimodal measurements of blood plasma and red blood cell volumes during functional brain activation. J Cereb Blood Flow Metab 2009; 29:19-24. [PMID: 18766196 PMCID: PMC2714270 DOI: 10.1038/jcbfm.2008.100] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
As an alternative to functional magnetic resonance imaging (fMRI) with blood oxygenation level dependent (BOLD) contrast, cerebral blood volume (CBV)-weighted fMRI with intravascular contrast agents in animal models have become popular. In this study, dynamic measurements of CBV were performed by magnetic resonance imaging (MRI) and laser-Doppler flowmetry (LDF) in alpha-chloralose anesthetized rats during forepaw stimulation. All recordings were localized to the contralateral primary somatosensory cortex as revealed by BOLD at 11.7 T. Ultra-small superparamagnetic iron oxide (15 mg/kg)--a plasma-borne MRI contrast agent with a half-life of several hours in blood circulation--was used to quantify changes in magnetic field inhomogeneity in blood plasma. The LDF backscattered laser light (805 nm), which reflects the amount of red blood cells, was used to measure alterations in the non-plasma compartment. Dynamic and layer-specific comparisons of the two CBV signals during functional hyperemia revealed excellent correlations (>0.86). These results suggest that CBV measurements from either compartment may be used to reflect dynamic changes in total CBV. Furthermore, by assuming steady-state mass balance and negligible counter flow, these results indicate that volume hematocrit is not appreciably affected during functional activation.
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41
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Pharmacological MRI in animal models: A useful tool for 5-HT research? Neuropharmacology 2008; 55:1038-47. [DOI: 10.1016/j.neuropharm.2008.08.014] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2008] [Revised: 08/06/2008] [Accepted: 08/07/2008] [Indexed: 01/19/2023]
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42
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Cutini S, Scatturin P, Menon E, Bisiacchi PS, Gamberini L, Zorzi M, Dell'Acqua R. Selective activation of the superior frontal gyrus in task-switching: An event-related fNIRS study. Neuroimage 2008; 42:945-55. [PMID: 18586525 DOI: 10.1016/j.neuroimage.2008.05.013] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2008] [Revised: 05/05/2008] [Accepted: 05/06/2008] [Indexed: 11/15/2022] Open
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43
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Franceschini MA, Nissilä I, Wu W, Diamond SG, Bonmassar G, Boas DA. Coupling between somatosensory evoked potentials and hemodynamic response in the rat. Neuroimage 2008; 41:189-203. [PMID: 18420425 DOI: 10.1016/j.neuroimage.2008.02.061] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2008] [Revised: 02/27/2008] [Accepted: 02/28/2008] [Indexed: 11/28/2022] Open
Abstract
We studied the relationship between somatosensory evoked potentials (SEP) recorded with scalp electroencephalography (EEG) and hemoglobin responses recorded non-invasively with diffuse optical imaging (DOI) during parametrically varied electrical forepaw stimulation in rats. Using these macroscopic techniques we verified that the hemodynamic response is not linearly coupled to the somatosensory evoked potentials, and that a power or threshold law best describes the coupling between SEP and the hemoglobin response, in agreement with the results of most invasive studies. We decompose the SEP response in three components (P1, N1, and P2) to determine which best predicts the hemoglobin response. We found that N1 and P2 predict the hemoglobin response significantly better than P1 and the input stimuli (S). Previous electrophysiology studies reported in the literature show that P1 originates in layer IV directly from thalamocortical afferents, while N1 and P2 originate in layers I and II and reflect the majority of local cortico-cortical interactions. Our results suggest that the evoked hemoglobin response is driven by the cortical synaptic activity and not by direct thalamic input. The N1 and P2 components, and not P1, need to be considered to correctly interpret neurovascular coupling.
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Affiliation(s)
- Maria Angela Franceschini
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, 13th Street Bldg. 149 (room 2301), Charlestown, MA 02129, USA.
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44
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A vascular anatomical network model of the spatio-temporal response to brain activation. Neuroimage 2008; 40:1116-29. [PMID: 18289880 DOI: 10.1016/j.neuroimage.2007.12.061] [Citation(s) in RCA: 166] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2007] [Revised: 12/01/2007] [Accepted: 12/30/2007] [Indexed: 11/23/2022] Open
Abstract
Neuronal activity-induced changes in vascular tone and oxygen consumption result in a dynamic evolution of blood flow, volume, and oxygenation. Functional neuroimaging techniques, such as functional magnetic resonance imaging, optical imaging, and PET, provide indirect measures of the neural-induced vascular dynamics driving the blood parameters. Models connecting changes in vascular tone and oxygen consumption to observed changes in the blood parameters are needed to guide more quantitative physiological interpretation of these functional neuroimaging modalities. Effective lumped-parameter vascular balloon and Windkessel models have been developed for this purpose, but the lumping of the complex vascular network into a series of arterioles, capillaries, and venules allows only qualitative interpretation. We have therefore developed a parallel vascular anatomical network (VAN) model based on microscopically measurable properties to improve quantitative interpretation of the vascular response. The model, derived from measured physical properties, predicts baseline blood pressure and oxygen saturation distributions and dynamic responses consistent with literature. Furthermore, the VAN model allows investigation of spatial features of the dynamic vascular and oxygen response to neuronal activity. We find that a passive surround negative vascular response ("negative BOLD") is predicted, but that it underestimates recently observed surround negativity suggesting that additional active surround vasoconstriction is required to explain the experimental data.
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45
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Berwick J, Johnston D, Jones M, Martindale J, Martin C, Kennerley AJ, Redgrave P, Mayhew JEW. Fine detail of neurovascular coupling revealed by spatiotemporal analysis of the hemodynamic response to single whisker stimulation in rat barrel cortex. J Neurophysiol 2007; 99:787-98. [PMID: 18046008 DOI: 10.1152/jn.00658.2007] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The spatial resolution of hemodynamic-based neuroimaging techniques, including functional magnetic resonance imaging, is limited by the degree to which neurons regulate their blood supply on a fine scale. Here we investigated the spatial detail of neurovascular events with a combination of high spatiotemporal resolution two-dimensional spectroscopic optical imaging, multichannel electrode recordings and cytochrome oxidase histology in the rodent whisker barrel field. After mechanical stimulation of a single whisker, we found two spatially distinct cortical hemodynamic responses: a transient response in the "upstream" branches of surface arteries and a later highly localized increase in blood volume centered on the activated cortical column. Although the spatial representation of this localized response exceeded that of a single "barrel," the spread of hemodynamic activity accurately reflected the neural response in neighboring columns rather than being due to a passive "overspill." These data confirm hemodynamics are capable of providing accurate "single-condition" maps of neural activity.
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Affiliation(s)
- J Berwick
- Department of Psychology, University of Sheffield, Sheffield S10 2TN, UK.
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46
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Zeff BW, White BR, Dehghani H, Schlaggar BL, Culver JP. Retinotopic mapping of adult human visual cortex with high-density diffuse optical tomography. Proc Natl Acad Sci U S A 2007; 104:12169-74. [PMID: 17616584 PMCID: PMC1924577 DOI: 10.1073/pnas.0611266104] [Citation(s) in RCA: 229] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2006] [Indexed: 11/18/2022] Open
Abstract
Functional neuroimaging is a vital element of neuroscience and cognitive research and, increasingly, is an important clinical tool. Diffuse optical imaging is an emerging, noninvasive technique with unique portability and hemodynamic contrast capabilities for mapping brain function in young subjects and subjects in enriched or clinical environments. We have developed a high-performance, high-density diffuse optical tomography (DOT) system that overcomes previous limitations and enables superior image quality. We show herein the utility of the DOT system by presenting functional hemodynamic maps of the adult human visual cortex. The functional brain images have a high contrast-to-noise ratio, allowing visualization of individual activations and highly repeatable mapping within and across subjects. With the improved spatial resolution and localization, we were able to image functional responses of 1.7 cm in extent and shifts of <1 cm. Cortical maps of angle and eccentricity in the visual field are consistent with retinotopic studies using functional MRI and positron-emission tomography. These results demonstrate that high-density DOT is a practical and powerful tool for mapping function in the human cortex.
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Affiliation(s)
- Benjamin W. Zeff
- *Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110
| | - Brian R. White
- Department of Physics and School of Medicine, Washington University, St. Louis, MO 63130; and
| | - Hamid Dehghani
- Department of Physics, University of Exeter, Exeter EX4 4QJ, United Kingdom
| | - Bradley L. Schlaggar
- *Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110
| | - Joseph P. Culver
- *Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110
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47
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Depth-resolved optical imaging and microscopy of vascular compartment dynamics during somatosensory stimulation. Neuroimage 2007; 35:89-104. [PMID: 17222567 DOI: 10.1016/j.neuroimage.2006.11.032] [Citation(s) in RCA: 199] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2006] [Revised: 10/26/2006] [Accepted: 11/17/2006] [Indexed: 10/23/2022] Open
Abstract
The cortical hemodynamic response to somatosensory stimulus is investigated at the level of individual vascular compartments using both depth-resolved optical imaging and in-vivo two-photon microscopy. We utilize a new imaging and spatiotemporal analysis approach that exploits the different characteristic dynamics of responding arteries, arterioles, capillaries and veins to isolate their three-dimensional spatial extent within the cortex. This spatial delineation is validated using vascular casts. Temporal delineation is supported by in-vivo two-photon microscopy of the temporal dynamics and vascular mechanisms of the arteriolar and venous responses. Using these techniques we have been able to characterize the roles of the different vascular compartments in generating and controlling the hemodynamic response to somatosensory stimulus. We find that changes in arteriolar total hemoglobin concentration agree well with arteriolar dilation dynamics, which in turn correspond closely with changes in venous blood flow. For 4-s stimuli, we see only small changes in venous hemoglobin concentration, and do not detect measurable dilation or ballooning in the veins. Instead, we see significant evidence of capillary hyperemia. We compare our findings to historical observations of the composite hemodynamic response from other modalities including functional magnetic resonance imaging. Implications of our results are discussed with respect to mathematical models of cortical hemodynamics, and to current theories on the mechanisms underlying neurovascular coupling. We also conclude that our spatiotemporal analysis approach is capable of isolating and localizing signals from the capillary bed local to neuronal activation, and holds promise for improving the specificity of other hemodynamic imaging modalities.
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48
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Luo W, Li P, Chen S, Zeng S, Luo Q. Differentiating hemodynamic responses in rat primary somatosensory cortex during non-noxious and noxious electrical stimulation by optical imaging. Brain Res 2006; 1133:67-77. [PMID: 17196176 DOI: 10.1016/j.brainres.2006.09.111] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2006] [Revised: 09/21/2006] [Accepted: 09/21/2006] [Indexed: 09/30/2022]
Abstract
Nociception in the primary somatosensory (S1) cortex remains in need of further elucidation. The spatiotemporal comparison on changes of the cerebral blood volume evoked by graded peripheral electrical stimulation was performed in rat contralateral somatosensory cortex with optical intrinsic signal imaging (OISI, optical reflectance at 550 nm). Non-noxious electrical stimulus was applied with 5 Hz pulses (0.5 ms peak duration) for 2 s at the threshold current for muscle twitch, while noxious stimulus was delivered at currents of 10x and 20x amplitude of the predetermined threshold. Although the dimensions of peak response defined in the spatial domain (cerebral blood volume increase) in the S1 cortex presented no significant difference under non-/noxious stimuli, its early response component (about 1 s after stimulation onset) revealed by OISI technique was suggested to differentiate the loci of activated cortical region due to different stimulation in this study. The magnitude and duration of the optical intrinsic signal (OIS) response was found increasing with the varying stimulus intensity. Regions activated by the delivery of a noxious stimulus were surrounded by a ring of inverted optical intrinsic signal, the amplitude of that was inversely proportional to the strength of the optical signal attributable to activation. Intense stimuli significantly augmented the inverted optical signal in magnitude and spatial extent. These results indicated that noxious stimulation evoked different response patterns in the contralateral S1 cortex. The magnitude-dependent inverted optical signal might contribute to the differentiation of nociceptive input in the S1 cortex.
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Affiliation(s)
- Weihua Luo
- Key Laboratory of Biomedical Photonics of Ministry of Education-Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, PR China
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Okamoto M, Dan H, Singh AK, Hayakawa F, Jurcak V, Suzuki T, Kohyama K, Dan I. Prefrontal activity during flavor difference test: Application of functional near-infrared spectroscopy to sensory evaluation studies. Appetite 2006; 47:220-32. [PMID: 16797780 DOI: 10.1016/j.appet.2006.04.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2006] [Revised: 04/04/2006] [Accepted: 04/14/2006] [Indexed: 11/16/2022]
Abstract
Sensory evaluation (SE) of food attributes involves various levels of cognitive functions, yet not much has been studied about its neural basis. Using multi-channel functional near-infrared spectroscopy (fNIRS), we examined the activation of the anterior portion of the lateral prefrontal cortex (LPFC) of 12 healthy volunteers during the SE of tea samples. The experimental task used corresponded to the early phase of the same-different test, and required subjects to attentively taste tea samples and memorize their flavors. To isolate activation associated with the cognitive functions involved in the task, we contrasted the results with those achieved by a control (Ctl) task during which subjects held familiar tea samples in their mouths without actively evaluating their flavor. We probabilistically registered the fNIRS data to the Montreal Neurological Institute standard brain space to examine the results as they correspond with other published neuroimaging studies. We found significant activation in the left LPFC and in the right inferior frontal gyrus. The activation pattern was consistent with earlier studies on encoding of other sensory stimuli, with cortical regions supposed to be involved in semantic and perceptual processing. This research makes a start on characterizing the cognitive process employed during SE from the neuroimaging perspective.
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Affiliation(s)
- Masako Okamoto
- National Food Research Institute, 2-1-12 Kannondai, Tsukuba 305-8642, Japan
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50
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Guilfoyle DN, Hrabe J. Interleaved snapshot echo planar imaging of mouse brain at 7.0 T. NMR IN BIOMEDICINE 2006; 19:108-15. [PMID: 16411168 DOI: 10.1002/nbm.1009] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Single-shot echo planar imaging (EPI) of a mouse brain at high field is very challenging. Large susceptibility-induced gradients affect much of the brain volume, causing severe image deformations and signal loss. Segmented EPI and other conventional multi-shot approaches alleviate these problems but suffer from lower temporal resolution and motion artifacts. We demonstrate that interleaved snapshot EPI represents a simple and robust alternative approach and one that is particularly suitable for high-field T2*-weighted functional imaging of a mouse brain. Similarly to segmented multi-shot techniques, it significantly reduces the susceptibility-related artifacts. At the same time, it preserves the high temporal resolution and the snapshot capability of a conventional EPI by acquiring entire image within a single TR period. We discuss implementation details of the interleaved snapshot EPI sequence and the trade-offs involved between the imaging efficiency, the number of interleaved excitation-acquisition blocks and the artifact reduction. To document the sequence utility, murine brain in vivo imaging with the interleaved snapshot EPI method was compared with a conventional EPI. We found that at least five interleaved blocks were necessary to restore the signal in most cortical areas. We also show that a standard global shimming procedure provides sufficient homogeneity for multi-slice interleaved snapshot EPI acquisition. In contrast, the conventional EPI of comparable image quality would be limited to a single slice with highly optimized local shim. Finally, an in vitro comparison with turbo FLASH acquisition shows the interleaved snapshot EPI to have superior time resolution and signal-to-noise ratio.
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Affiliation(s)
- David N Guilfoyle
- Center for Advanced Brain Imaging, Nathan S. Kline Institute for Psychiatric Research, 140 Old Orangeburg Road, Orangeburg, NY 10962, USA.
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