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Sengupta A, Wang F, Mishra A, Reed JL, Chen LM, Gore JC. Detection and characterization of resting state functional networks in squirrel monkey brain. Cereb Cortex Commun 2023; 4:tgad018. [PMID: 37753115 PMCID: PMC10518810 DOI: 10.1093/texcom/tgad018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 08/22/2023] [Accepted: 08/23/2023] [Indexed: 09/28/2023] Open
Abstract
Resting-state fMRI based on analyzing BOLD signals is widely used to derive functional networks in the brain and how they alter during disease or injury conditions. Resting-state networks can also be used to study brain functional connectomes across species, which provides insights into brain evolution. The squirrel monkey (SM) is a non-human primate (NHP) that is widely used as a preclinical model for experimental manipulations to understand the organization and functioning of the brain. We derived resting-state networks from the whole brain of anesthetized SMs using Independent Component Analysis of BOLD acquisitions. We detected 15 anatomically constrained resting-state networks localized in the cortical and subcortical regions as well as in the white-matter. Networks encompassing visual, somatosensory, executive control, sensorimotor, salience and default mode regions, and subcortical networks including the Hippocampus-Amygdala, thalamus, basal-ganglia and brainstem region correspond well with previously detected networks in humans and NHPs. The connectivity pattern between the networks also agrees well with previously reported seed-based resting-state connectivity of SM brain. This study demonstrates that SMs share remarkable homologous network organization with humans and other NHPs, thereby providing strong support for their suitability as a translational animal model for research and additional insight into brain evolution across species.
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Affiliation(s)
- Anirban Sengupta
- Vanderbilt University Institute of Imaging Science, Nashville, Vanderbilt University Medical Center, Nashville, TN, United States of America
- Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States of America
| | - Feng Wang
- Vanderbilt University Institute of Imaging Science, Nashville, Vanderbilt University Medical Center, Nashville, TN, United States of America
- Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States of America
| | - Arabinda Mishra
- Vanderbilt University Institute of Imaging Science, Nashville, Vanderbilt University Medical Center, Nashville, TN, United States of America
- Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States of America
| | - Jamie L Reed
- Vanderbilt University Institute of Imaging Science, Nashville, Vanderbilt University Medical Center, Nashville, TN, United States of America
- Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States of America
- Department of Psychology, Vanderbilt University, Nashville, TN, United States of America
| | - Li Min Chen
- Vanderbilt University Institute of Imaging Science, Nashville, Vanderbilt University Medical Center, Nashville, TN, United States of America
- Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States of America
- Biomedical Engineering, Vanderbilt University, Nashville, TN, United States of America
| | - John C Gore
- Vanderbilt University Institute of Imaging Science, Nashville, Vanderbilt University Medical Center, Nashville, TN, United States of America
- Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States of America
- Biomedical Engineering, Vanderbilt University, Nashville, TN, United States of America
- Department of Physics and Astronomy, Vanderbilt University, Nashville, TN, United States of America
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Ferris CF. Applications in Awake Animal Magnetic Resonance Imaging. Front Neurosci 2022; 16:854377. [PMID: 35450017 PMCID: PMC9017993 DOI: 10.3389/fnins.2022.854377] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 03/09/2022] [Indexed: 12/16/2022] Open
Abstract
There are numerous publications on methods and applications for awake functional MRI across different species, e.g., voles, rabbits, cats, dogs, and rhesus macaques. Each of these species, most obviously rhesus monkey, have general or unique attributes that provide a better understanding of the human condition. However, much of the work today is done on rodents. The growing number of small bore (≤30 cm) high field systems 7T- 11.7T favor the use of small animals. To that point, this review is primarily focused on rodents and their many applications in awake function MRI. Applications include, pharmacological MRI, drugs of abuse, sensory evoked stimuli, brain disorders, pain, social behavior, and fear.
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Gu Y, Wang L, Yang H, Wu Y, Kim K, Zhu Y, Androjna C, Zhu X, Chen Y, Zhong K, Yu X. Three-dimensional high-resolution T 1 and T 2 mapping of whole macaque brain at 9.4 T using magnetic resonance fingerprinting. Magn Reson Med 2022; 87:2901-2913. [PMID: 35129226 DOI: 10.1002/mrm.29181] [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: 12/08/2021] [Revised: 01/10/2022] [Accepted: 01/10/2022] [Indexed: 11/12/2022]
Abstract
PURPOSE Quantitative T1 and T2 mapping in non-human primates with whole-brain coverage is challenged by the requirement of sub-millimeter resolution and the inhomogeneity of the transmit magnetic field (B1 + ) covering a large field of view. The goal of the current study is to develop a magnetic resonance fingerprinting (MRF) method for simultaneous T1 and T2 mapping of the entire macaque brain within feasible scan time. METHODS A three-dimensional (3D) MRF sequence with both inversion- and T2 -preparation modules was developed and evaluated on a 9.4 T preclinical scanner. Data acquisition used a 3D stack-of-spirals trajectory, with undersampling along both the in-plane and the through-plane directions. The effect of B1 + inhomogeneity was accounted for by matching the acquired fingerprint to a dictionary simulated with the B1 + factors measured from a separate scan. In vitro and ex vivo studies were performed to evaluate the accuracy and the undersampling capacity of the MRF method. The application of the MRF method for in vivo, brain-wide T1 and T2 mapping was demonstrated on macaques at 4, 6, and 12 years of age. RESULTS The MRF method enabled highly repeatable T1 and T2 mapping at high spatial resolution (0.35 × 0.35 × 1 mm3 ) with an acceleration factor of 24. In vivo studies showed significant age-related T2 reduction in deep gray nuclei including the globus pallidus, the putamen, and the caudate nucleus. CONCLUSIONS This study demonstrates the first MRF study for brain-wide, multi-parametric quantification in non-human primates with sub-millimeter resolution.
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Affiliation(s)
- Yuning Gu
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
| | - Lulu Wang
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, China.,Anhui Province Key Laboratory of High Field Magnetic Resonance Imaging, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China
| | - Hongyi Yang
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, China.,Anhui Province Key Laboratory of High Field Magnetic Resonance Imaging, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China.,School of Graduate Studies, Science Island Branch, University of Science and Technology of China, Hefei, China
| | - Yun Wu
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, China.,Anhui Province Key Laboratory of High Field Magnetic Resonance Imaging, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China
| | - Kihwan Kim
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
| | - Yuran Zhu
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
| | - Charlie Androjna
- Center for Preclinical Magnetic Resonance Imaging, Cleveland Clinic Foundation, Cleveland, Ohio, USA
| | - Xiaofeng Zhu
- Department of Epidemiology and Biostatistics, Case Western Reserve University, Cleveland, Ohio, USA
| | - Yong Chen
- Department of Radiology, Case Western Reserve University, Cleveland, Ohio, USA
| | - Kai Zhong
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, China.,Anhui Province Key Laboratory of High Field Magnetic Resonance Imaging, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China.,Biomedical Engineering Department, Peking University, Beijing, China
| | - Xin Yu
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA.,Department of Radiology, Case Western Reserve University, Cleveland, Ohio, USA
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Basso MA, Frey S, Guerriero KA, Jarraya B, Kastner S, Koyano KW, Leopold DA, Murphy K, Poirier C, Pope W, Silva AC, Tansey G, Uhrig L. Using non-invasive neuroimaging to enhance the care, well-being and experimental outcomes of laboratory non-human primates (monkeys). Neuroimage 2021; 228:117667. [PMID: 33359353 PMCID: PMC8005297 DOI: 10.1016/j.neuroimage.2020.117667] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 12/16/2020] [Accepted: 12/17/2020] [Indexed: 02/09/2023] Open
Abstract
Over the past 10-20 years, neuroscience witnessed an explosion in the use of non-invasive imaging methods, particularly magnetic resonance imaging (MRI), to study brain structure and function. Simultaneously, with access to MRI in many research institutions, MRI has become an indispensable tool for researchers and veterinarians to guide improvements in surgical procedures and implants and thus, experimental as well as clinical outcomes, given that access to MRI also allows for improved diagnosis and monitoring for brain disease. As part of the PRIMEatE Data Exchange, we gathered expert scientists, veterinarians, and clinicians who treat humans, to provide an overview of the use of non-invasive imaging tools, primarily MRI, to enhance experimental and welfare outcomes for laboratory non-human primates engaged in neuroscientific experiments. We aimed to provide guidance for other researchers, scientists and veterinarians in the use of this powerful imaging technology as well as to foster a larger conversation and community of scientists and veterinarians with a shared goal of improving the well-being and experimental outcomes for laboratory animals.
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Affiliation(s)
- M A Basso
- Fuster Laboratory of Cognitive Neuroscience, Department of Psychiatry and Biobehavioral Sciences UCLA Los Angeles CA 90095 USA
| | - S Frey
- Rogue Research, Inc. Montreal, QC, Canada
| | - K A Guerriero
- Washington National Primate Research Center University of Washington Seattle, WA USA
| | - B Jarraya
- Cognitive Neuroimaging Unit, INSERM, CEA, NeuroSpin center, 91191 Gif/Yvette, France; Université Paris-Saclay, UVSQ, Foch hospital, Paris, France
| | - S Kastner
- Princeton Neuroscience Institute & Department of Psychology Princeton University Princeton, NJ USA
| | - K W Koyano
- National Institute of Mental Health NIH Bethesda MD 20892 USA
| | - D A Leopold
- National Institute of Mental Health NIH Bethesda MD 20892 USA
| | - K Murphy
- Biosciences Institute and Centre for Behaviour and Evolution, Faculty of Medical Sciences Newcastle University Newcastle upon Tyne NE2 4HH United Kingdom UK
| | - C Poirier
- Biosciences Institute and Centre for Behaviour and Evolution, Faculty of Medical Sciences Newcastle University Newcastle upon Tyne NE2 4HH United Kingdom UK
| | - W Pope
- Department of Radiology UCLA Los Angeles, CA 90095 USA
| | - A C Silva
- Department of Neurobiology University of Pittsburgh, Pittsburgh PA 15261 USA
| | - G Tansey
- National Eye Institute NIH Bethesda MD 20892 USA
| | - L Uhrig
- Cognitive Neuroimaging Unit, INSERM, CEA, NeuroSpin center, 91191 Gif/Yvette, France
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Zhang X, Zhang J, Gao Y, Qian M, Qu S, Quan Z, Yu M, Chen X, Wang Y, Pan G, Adriany G, Roe AW. A 16-Channel Dense Array for In Vivo Animal Cortical MRI/fMRI on 7T Human Scanners. IEEE Trans Biomed Eng 2020; 68:1611-1618. [PMID: 32991277 DOI: 10.1109/tbme.2020.3027296] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
OBJECTIVE The purpose of the present study was to fabricate a novel RF coil exclusively for visualizing submillimeter tissue structure and probing neuronal activity in cerebral cortex over anesthetized and awake animals on 7T human scanners. METHODS A novel RF coil design has been proposed for visualizing submillimeter tissue structure and probing neuronal activity in cerebral cortex over anesthetized and awake animals on 7T human scanners: a local transmit coil was utilized to save space for auxiliary device installation; 16 receive-only loops were densely arranged over a 5 cm-diameter circular area, with a diameter of 1.3 cm for each loop. RESULTS In anesthetized macaque experiments, 60 μm T2*-weighted images were successfully obtained with cortical gyri and sulci exquisitely visualized; over awake macaques, bilateral activations of visual areas including V1, V2, V4, and MST were distinctly detected at 1 mm; over the cat, robust activations were recorded in areas 17 and 18 (V1 and V2) as well as in their connected area of lateral geniculate nucleus (LGN) at 0.3 mm resolution. CONCLUSION The promising brain imaging results along with flexibility in various size use of the presented design can be an effective and maneuverable solution to take one step close towards mesoscale cortical-related imaging. SIGNIFICANCE High-spatial-resolution brain imaging over large animals by using ultra-high-field (UHF) MRI will be helpful to understand and reveal functional brain organizations and the underlying mechanism in diseases.
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Gilbert KM, Schaeffer DJ, Zeman P, Diedrichsen J, Everling S, Martinez-Trujillo JC, Pruszynski JA, Menon RS. Concentric radiofrequency arrays to increase the statistical power of resting-state maps in monkeys. Neuroimage 2018; 178:287-294. [PMID: 29852280 DOI: 10.1016/j.neuroimage.2018.05.057] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 05/23/2018] [Accepted: 05/24/2018] [Indexed: 12/30/2022] Open
Abstract
The close homology of monkeys and humans has increased the prevalence of non-human-primate models in functional MRI studies of brain connectivity. To improve upon the attainable resolution in functional MRI studies, a commensurate increase in the sensitivity of the radiofrequency receiver coil is required to avoid a reduction in the statistical power of the analysis. Most receive coils are comprised of multiple loops distributed equidistantly over a surface to produce spatially independent sensitivity profiles. A larger number of smaller elements will in turn provide a higher signal-to-noise ratio (SNR) over the same field of view. As the loops become physically smaller, noise originating from the sample is reduced relative to noise originating from the coil. In this coil-noise-dominated regime, coil elements can have overlapping sensitivity profiles, yet still possess only mildly correlated noise. In this manuscript, we demonstrate that inductively decoupled, concentric coil arrays can improve temporal SNR when operating in the coil-noise-dominated regime-in contrast to what is expected for the more ubiquitous sample-noise-dominated array. A small, thin, 7-channel flexible coil is developed and operated in conjunction with an existing whole-head monkey coil. The mean and maximum noise correlation between the two arrays was 5% and 23%, respectively. When the flex coil was placed over the sensorimotor cortex, the temporal SNR improved by up to 2.3-fold in the peripheral cortex and up to 1.3-fold at a 2- to 3-cm depth within the brain. When the flex coil was placed over the frontal eye fields, resting-state maps showed substantially elevated sensitivity to correlations in the prefrontal cortex (54%), supplementary eye fields (39%), and anterior cingulate cortex (41%). The concentric-coil topology provided a pragmatic and robust means to significantly improve local temporal SNR and the statistical power of functional connectivity maps.
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Affiliation(s)
- Kyle M Gilbert
- Centre for Functional and Metabolic Mapping, The University of Western Ontario, London, Ontario, Canada.
| | - David J Schaeffer
- Centre for Functional and Metabolic Mapping, The University of Western Ontario, London, Ontario, Canada
| | - Peter Zeman
- Centre for Functional and Metabolic Mapping, The University of Western Ontario, London, Ontario, Canada
| | - Jörn Diedrichsen
- Department of Computer Science, The University of Western Ontario, London, Ontario, Canada
| | - Stefan Everling
- Centre for Functional and Metabolic Mapping, The University of Western Ontario, London, Ontario, Canada; Department of Physiology and Pharmacology, The University of Western Ontario, London, Ontario, Canada
| | - Julio C Martinez-Trujillo
- Department of Physiology and Pharmacology, The University of Western Ontario, London, Ontario, Canada
| | - J Andrew Pruszynski
- Department of Physiology and Pharmacology, The University of Western Ontario, London, Ontario, Canada
| | - Ravi S Menon
- Centre for Functional and Metabolic Mapping, The University of Western Ontario, London, Ontario, Canada
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Zhang W, Jiang X, Zhang S, Howell BR, Zhao Y, Zhang T, Guo L, Sanchez MM, Hu X, Liu T. Connectome-scale functional intrinsic connectivity networks in macaques. Neuroscience 2017; 364:1-14. [PMID: 28842187 DOI: 10.1016/j.neuroscience.2017.08.022] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 08/10/2017] [Accepted: 08/11/2017] [Indexed: 01/06/2023]
Abstract
There have been extensive studies of intrinsic connectivity networks (ICNs) in the human brains using resting-state functional magnetic resonance imaging (fMRI) in the literature. However, the functional organization of ICNs in macaque brains has been less explored so far, despite growing interests in the field. In this work, we propose a computational framework to identify connectome-scale group-wise consistent ICNs in macaques via sparse representation of whole-brain resting-state fMRI data. Experimental results demonstrate that 70 group-wise consistent ICNs are successfully identified in macaque brains via the proposed framework. These 70 ICNs are interpreted based on two publicly available parcellation maps of macaque brains and our work significantly expand currently known macaque ICNs already reported in the literature. In general, this set of connectome-scale group-wise consistent ICNs can potentially benefit a variety of studies in the neuroscience and brain-mapping fields, and they provide a foundation to better understand brain evolution in the future.
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Affiliation(s)
- Wei Zhang
- Cortical Architecture Imaging and Discovery Lab, Department of Computer Science and Bioimaging Research Center, The University of Georgia, Athens, GA, USA
| | - Xi Jiang
- Cortical Architecture Imaging and Discovery Lab, Department of Computer Science and Bioimaging Research Center, The University of Georgia, Athens, GA, USA
| | - Shu Zhang
- Cortical Architecture Imaging and Discovery Lab, Department of Computer Science and Bioimaging Research Center, The University of Georgia, Athens, GA, USA
| | - Brittany R Howell
- Department of Psychiatry & Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, USA; Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA; Institute of Child Development, University of Minnesota, Minneapolis, MN, USA
| | - Yu Zhao
- Cortical Architecture Imaging and Discovery Lab, Department of Computer Science and Bioimaging Research Center, The University of Georgia, Athens, GA, USA
| | - Tuo Zhang
- School of Automation, Northwestern Polytechnical University, Xi'an, PR China; Cortical Architecture Imaging and Discovery Lab, Department of Computer Science and Bioimaging Research Center, The University of Georgia, Athens, GA, USA
| | - Lei Guo
- School of Automation, Northwestern Polytechnical University, Xi'an, PR China
| | - Mar M Sanchez
- Department of Psychiatry & Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, USA; Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA
| | - Xiaoping Hu
- Department of Bioengineering, UC Riverside, CA, USA
| | - Tianming Liu
- Cortical Architecture Imaging and Discovery Lab, Department of Computer Science and Bioimaging Research Center, The University of Georgia, Athens, GA, USA.
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Gilbert KM, Gati JS, Barker K, Everling S, Menon RS. Optimized parallel transmit and receive radiofrequency coil for ultrahigh-field MRI of monkeys. Neuroimage 2016; 125:153-161. [DOI: 10.1016/j.neuroimage.2015.10.048] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Revised: 10/08/2015] [Accepted: 10/19/2015] [Indexed: 12/14/2022] Open
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Abstract
In 1998 several groups reported the feasibility of fMRI experiments in monkeys, with the goal to bridge the gap between invasive nonhuman primate studies and human functional imaging. These studies yielded critical insights in the neuronal underpinnings of the BOLD signal. Furthermore, the technology has been successful in guiding electrophysiological recordings and identifying focal perturbation targets. Finally, invaluable information was obtained concerning human brain evolution. We here provide a comprehensive overview of awake monkey fMRI studies mainly confined to the visual system. We review the latest insights about the topographic organization of monkey visual cortex and discuss the spatial relationships between retinotopy and category- and feature-selective clusters. We briefly discuss the functional layout of parietal and frontal cortex and continue with a summary of some fascinating functional and effective connectivity studies. Finally, we review recent comparative fMRI experiments and speculate about the future of nonhuman primate imaging.
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Affiliation(s)
- Wim Vanduffel
- Laboratory for Neuro- and Psychophysiology, KU Leuven Medical School, Campus Gasthuisberg, Leuven, 3000, Belgium; Department of Radiology, Harvard Medical School, Boston, MA 02129, USA; A.A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA 02129, USA.
| | - Qi Zhu
- Laboratory for Neuro- and Psychophysiology, KU Leuven Medical School, Campus Gasthuisberg, Leuven, 3000, Belgium
| | - Guy A Orban
- Laboratory for Neuro- and Psychophysiology, KU Leuven Medical School, Campus Gasthuisberg, Leuven, 3000, Belgium; Department of Neuroscience, University of Parma, Parma, 43125, Italy
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Seah S, Asad ABA, Baumgartner R, Feng D, Williams DS, Manigbas E, Beaver JD, Reese T, Henry B, Evelhoch JL, Chin CL. Investigation of cross-species translatability of pharmacological MRI in awake nonhuman primate - a buprenorphine challenge study. PLoS One 2014; 9:e110432. [PMID: 25337714 PMCID: PMC4206294 DOI: 10.1371/journal.pone.0110432] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 09/22/2014] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Pharmacological MRI (phMRI) is a neuroimaging technique where drug-induced hemodynamic responses can represent a pharmacodynamic biomarker to delineate underlying biological consequences of drug actions. In most preclinical studies, animals are anesthetized during image acquisition to minimize movement. However, it has been demonstrated anesthesia could attenuate basal neuronal activity, which can confound interpretation of drug-induced brain activation patterns. Significant efforts have been made to establish awake imaging in rodents and nonhuman primates (NHP). Whilst various platforms have been developed for imaging awake NHP, comparison and validation of phMRI data as translational biomarkers across species remain to be explored. METHODOLOGY We have established an awake NHP imaging model that encompasses comprehensive acclimation procedures with a dedicated animal restrainer. Using a cerebral blood volume (CBV)-based phMRI approach, we have determined differential responses of brain activation elicited by the systemic administration of buprenorphine (0.03 mg/kg i.v.), a partial µ-opioid receptor agonist, in the same animal under awake and anesthetized conditions. Additionally, region-of-interest analyses were performed to determine regional drug-induced CBV time-course data and corresponding area-under-curve (AUC) values from brain areas with high density of µ-opioid receptors. PRINCIPAL FINDINGS In awake NHPs, group-level analyses revealed buprenorphine significantly activated brain regions including, thalamus, striatum, frontal and cingulate cortices (paired t-test, versus saline vehicle, p<0.05, n = 4). This observation is strikingly consistent with µ-opioid receptor distribution depicted by [6-O-[(11)C]methyl]buprenorphine ([(11)C]BPN) positron emission tomography imaging study in baboons. Furthermore, our findings are consistent with previous buprenorphine phMRI studies in humans and conscious rats which collectively demonstrate the cross-species translatability of awake imaging. Conversely, no significant change in activated brain regions was found in the same animals imaged under the anesthetized condition. CONCLUSIONS Our data highlight the utility and importance of awake NHP imaging as a translational imaging biomarker for drug research.
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Affiliation(s)
- Stephanie Seah
- Imaging, Merck & Co. Inc., West Point, Pennsylvania, United States of America
- Translational Medicine Research Centre, MSD, Singapore, Singapore
| | - Abu Bakar Ali Asad
- Imaging, Merck & Co. Inc., West Point, Pennsylvania, United States of America
- Translational Medicine Research Centre, MSD, Singapore, Singapore
| | - Richard Baumgartner
- Biostatistics and Research Decision Sciences, Merck & Co. Inc., Rahway, New Jersey, United States of America
| | - Dai Feng
- Biostatistics and Research Decision Sciences, Merck & Co. Inc., Rahway, New Jersey, United States of America
| | - Donald S. Williams
- Imaging, Merck & Co. Inc., West Point, Pennsylvania, United States of America
| | | | | | - Torsten Reese
- Translational Medicine Research Centre, MSD, Singapore, Singapore
| | - Brian Henry
- Translational Medicine Research Centre, MSD, Singapore, Singapore
| | - Jeffrey L. Evelhoch
- Imaging, Merck & Co. Inc., West Point, Pennsylvania, United States of America
| | - Chih-Liang Chin
- Imaging, Merck & Co. Inc., West Point, Pennsylvania, United States of America
- Translational Medicine Research Centre, MSD, Singapore, Singapore
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Orban GA, Zhu Q, Vanduffel W. The transition in the ventral stream from feature to real-world entity representations. Front Psychol 2014; 5:695. [PMID: 25071663 PMCID: PMC4079243 DOI: 10.3389/fpsyg.2014.00695] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Accepted: 06/16/2014] [Indexed: 11/29/2022] Open
Abstract
We propose that the ventral visual pathway of human and non-human primates is organized into three levels: (1) ventral retinotopic cortex including what is known as TEO in the monkey but corresponds to V4A and PITd/v, and the phPIT cluster in humans, (2) area TE in the monkey and its homolog LOC and neighboring fusiform regions, and more speculatively, (3) TGv in the monkey and its possible human equivalent, the temporal pole. We attribute to these levels the visual representations of features, partial real-world entities (RWEs), and known, complete RWEs, respectively. Furthermore, we propose that the middle level, TE and its homolog, is organized into three parallel substreams, lower bank STS, dorsal convexity of TE, and ventral convexity of TE, as are their corresponding human regions. These presumably process shape in depth, 2D shape and material properties, respectively, to construct RWE representations.
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Affiliation(s)
- Guy A Orban
- Department of Neuroscience, University of Parma Parma, Italy
| | - Qi Zhu
- Laboratorium voor Neuro-en Psychofysiologie, Department of Neuroscience KU Leuven, Leuven, Belgium
| | - Wim Vanduffel
- Laboratorium voor Neuro-en Psychofysiologie, Department of Neuroscience KU Leuven, Leuven, Belgium
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Papoti D, Yen CCC, Mackel JB, Merkle H, Silva AC. An embedded four-channel receive-only RF coil array for fMRI experiments of the somatosensory pathway in conscious awake marmosets. NMR IN BIOMEDICINE 2013; 26:1395-1402. [PMID: 23696219 PMCID: PMC4200535 DOI: 10.1002/nbm.2965] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Revised: 03/22/2013] [Accepted: 03/25/2013] [Indexed: 06/01/2023]
Abstract
fMRI has established itself as the main research tool in neuroscience and brain cognitive research. The common marmoset (Callithrix jacchus) is a non-human primate model of increasing interest in biomedical research. However, commercial MRI coils for marmosets are not generally available. The present work describes the design and construction of a four-channel receive-only surface RF coil array with excellent signal-to-noise ratio (SNR) specifically optimized for fMRI experiments in awake marmosets in response to somatosensory stimulation. The array was designed as part of a helmet-based head restraint system used to prevent motion during the scans. High SNR was obtained by building the coil array using a thin and flexible substrate glued to the inner surface of the restraint helmet, so as to minimize the distance between the array elements and the somatosensory cortex. Decoupling between coil elements was achieved by partial geometrical overlapping and by connecting them to home-built low-input-impedance preamplifiers. In vivo images show excellent coverage of the brain cortical surface with high sensitivity near the somatosensory cortex. Embedding the coil elements within the restraint helmet allowed fMRI data in response to somatosensory stimulation to be collected with high sensitivity and reproducibility in conscious, awake marmosets.
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Affiliation(s)
| | | | | | | | - Afonso C. Silva
- Address for correspondence: Afonso C. Silva, Ph.D., Chief, Cerebral Microcirculation Unit, Laboratory of Functional and Molecular Imaging, National Institute of neurological Disorders and Stroke, National Institutes of Health, 10 Center Drive MSC 1065, Building 10, Room B1D106, Bethesda, MD, 20892-1065, USA, Phone: +1-301-402-9703, Fax: +1-301-480-2558,
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Hadj-Bouziane F, Monfardini E, Guedj C, Gardechaux G, Hynaux C, Farnè A, Meunier M. The helmet head restraint system: a viable solution for resting state fMRI in awake monkeys. Neuroimage 2013; 86:536-43. [PMID: 24121168 DOI: 10.1016/j.neuroimage.2013.09.068] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Revised: 09/23/2013] [Accepted: 09/25/2013] [Indexed: 11/18/2022] Open
Abstract
In monkey neuroimaging, head restraint is currently achieved via surgical implants. Eradicating such invasive head restraint from otherwise non-invasive monkey studies could represent a substantial progress in terms of Reduction and Refinement. Two non-invasive helmet-based methods are available but they are used exclusively by the pioneering research groups who designed them. In the absence of independent replication, they have had little impact in replacing the surgical implants. Here, we built a modified version of the helmet system proposed by Srihasam et al. (2010 NeuroImage, 51(1), 267-73) and tested it for resting state fMRI in awake monkeys. Extremely vulnerable to motion artifacts, resting state fMRI represents a decisive test for non-invasive head restraint systems. We compared two monkeys restrained with the helmet to one monkey with a surgically implanted head post using both a seed-based approach and an independent component analysis. Technically, the helmet system proved relatively easy to develop. Scientifically, although it allowed more extensive movements than the head post system, the helmet proved viable for resting state fMRI, in particular when combined with the independent component analysis that deals more effectively with movement-related noise than the seed-based approach. We also discuss the pros and cons of such device in light of the European Union new 2013 regulation on non-human primate research and its firm Reduction and Refinement requests.
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Affiliation(s)
- Fadila Hadj-Bouziane
- INSERM, U1028, CNRS UMR5292, Lyon Neuroscience Research Center, ImpAct Team, Lyon F-69000, France; University UCBL Lyon 1, F-69000, France.
| | - Elisabetta Monfardini
- INSERM, U1028, CNRS UMR5292, Lyon Neuroscience Research Center, ImpAct Team, Lyon F-69000, France; University UCBL Lyon 1, F-69000, France; Institut de Médecine Environnementale, Paris F-75007, France
| | - Carole Guedj
- INSERM, U1028, CNRS UMR5292, Lyon Neuroscience Research Center, ImpAct Team, Lyon F-69000, France; University UCBL Lyon 1, F-69000, France
| | - Gislène Gardechaux
- INSERM, U1028, CNRS UMR5292, Lyon Neuroscience Research Center, ImpAct Team, Lyon F-69000, France; University UCBL Lyon 1, F-69000, France
| | - Clément Hynaux
- INSERM, U1028, CNRS UMR5292, Lyon Neuroscience Research Center, ImpAct Team, Lyon F-69000, France; University UCBL Lyon 1, F-69000, France
| | - Alessandro Farnè
- INSERM, U1028, CNRS UMR5292, Lyon Neuroscience Research Center, ImpAct Team, Lyon F-69000, France; University UCBL Lyon 1, F-69000, France
| | - Martine Meunier
- INSERM, U1028, CNRS UMR5292, Lyon Neuroscience Research Center, ImpAct Team, Lyon F-69000, France; University UCBL Lyon 1, F-69000, France
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14
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Ma M, Qian C, Li Y, Zuo Z, Liu Z. Setup and data analysis for functional magnetic resonance imaging of awake cat visual cortex. Neurosci Bull 2013; 29:588-602. [PMID: 23765516 DOI: 10.1007/s12264-013-1349-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Accepted: 02/17/2013] [Indexed: 10/26/2022] Open
Abstract
Functional magnetic resonance imaging (fMRI) is one of the most commonly used methods in cognitive neuroscience on humans. In recent decades, fMRI has also been used in the awake monkey experiments to localize functional brain areas and to compare the functional differences between human and monkey brains. Several procedures and paradigms have been developed to maintain proper head fixation and to perform motion control training. In this study, we extended the application of fMRI to awake cats without training, receiving a flickering checkerboard visual stimulus projected to a screen in front of them in a block-design paradigm. We found that body movement-induced non-rigid motion introduced artifacts into the functional scans, especially those around the eye and neck. To correct for these artifacts, we developed two methods: one for general experimental design, and the other for studies of whether a checkerboard task could be used as a localizer to optimize the motion-correction parameters. The results demonstrated that, with proper animal fixation and motion correction procedures, it is possible to perform fMRI experiments with untrained awake cats.
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Affiliation(s)
- Manxiu Ma
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
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15
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Logothetis NK. Intracortical recordings and fMRI: an attempt to study operational modules and networks simultaneously. Neuroimage 2012; 62:962-9. [PMID: 22248575 DOI: 10.1016/j.neuroimage.2012.01.033] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Revised: 12/22/2011] [Accepted: 01/01/2012] [Indexed: 11/26/2022] Open
Abstract
The brain can be envisaged as a complex adaptive system. It is characterized by a very high structural complexity and by massive connectivity, both of which change and evolve in response to experience. Information related to sensors and effectors is processed in both a parallel and a hierarchical fashion; the connectivity between different hierarchical levels is bidirectional, and its effectiveness is continuously controlled by specific associational and neuromodulatory centers. When questions are addressed at the level of a distributed, large-scale whole system such as that underlying perception and cognition, it is not clear what should be considered as an elementary operational unit because the behavior of integral, aggregate systems is always emergent and most often remains unpredicted by the behaviors of single cells. To localize and comprehend the neural mechanisms underlying our perceptual or cognitive capacities, concurrent studies of microcircuits, of local and long-range interconnectivity between small assemblies, and of the synergistic activity of larger neuronal populations are called for. In other words, multimodal methodologies that include invasive neuroscientific methods as well as global neuroimaging techniques are required, such as the various functional aspects of magnetic resonance imaging. These facts were the driving force behind the decision to begin animal-MRI in my lab. The wonderful idea of the editors of NeuroImage to publish a Special Issue commemorating 20years of functional fMRI provides me with the opportunity of sharing not only our first moments of frustration with the readers, but also our successful results.
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16
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Dubowitz DJ, Scadeng M. A frameless stereotaxic MRI technique for macaque neuroscience studies. Open Neuroimag J 2011; 5:198-205. [PMID: 22253662 PMCID: PMC3257065 DOI: 10.2174/1874440001105010198] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Revised: 01/06/2011] [Accepted: 01/14/2011] [Indexed: 12/03/2022] Open
Abstract
MRI has achieved widespread use for preplanning neuroscience procedures for non-human primate studies. However, orienting imaging studies in stereotaxic space has relied primarily on using a stereotaxic frame or co-registering fiducial markers with the neuroimaging. In this study, we present a simple approach in which the MRI dataset is aligned to the bony landmarks that define the Frankfurt stereotaxic baseline plane, without the need for a stereotaxic frame or additional external fiducials. To facilitate localizing the bony landmarks (infraorbital margin, external bony auditory meatus) on the MRI scans additional imaging landmarks (mid ocular plane, temporomandibular joint) are discussed that provide supplementary and readily visible points of reference. The frameless MRI stereotaxic technique was evaluated in 8 rhesus macaque monkeys using 3D fast gradient echo MRI images with 0.7mm isotropic resolution. 1) Difference in stereotaxic coordinates of fiducial markers was compared between a traditional stereotaxic frame and the frameless MRI technique (n=2). 2) Differences in stereotaxic coordinates for cerebral regions were compared between the frameless MRI technique and MRI obtained with the animal positioned in a MRI-compatible stereotaxic frame (n=4). 3) The frameless MRI technique was further refined to prescribe electrode penetrations within a dural recording chamber in stereotaxic coordinates relative to the electrode microdrive. Differences in MRI coordinates were compared with the electrode microdrive (n=3). Mean localization of fiducial markers differed by 1.6 +/- 0.6 mm between the frameless MRI technique and a traditional stereotaxic frame. Between the frameless technique and an MRI-compatible stereotaxic frame, localization of cerebral anatomy differed by 2.8 +/- 2.2 mm with the primary source of error being a pitch-up rotation in the sagittal plane. This localization difference was reduced to 0.5 +/- 0.6 mm when this rotation was removed. Frameless MRI coordinates for electrode tracts within the dural recording chamber were within 0.5mm +/- 0.2 mm of the electrode microdrive readings. This simple technique provides the ability to accurately plan surgery and neurophysiological recordings in an individual animal, and to define the location of cerebral anatomy and electrode or injection tracts using publically available software, and without the need for dedicated MRI-compatible localization hardware. The reduced need for deep anesthesia (a necessity with traditional stereotaxic frames) makes the technique more amenable for functional MRI studies. Since each animal provides the bony landmarks to define their own stereotaxic space, this technique is readily applicable to other species.
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Affiliation(s)
- David J Dubowitz
- Center for Functional Magnetic Resonance Imaging, Department of Radiology, University of California San Diego, La Jolla, CA 92093-0677, USA
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17
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Chen G, Wang F, Dillenburger BC, Friedman RM, Chen LM, Gore JC, Avison MJ, Roe AW. Functional magnetic resonance imaging of awake monkeys: some approaches for improving imaging quality. Magn Reson Imaging 2011; 30:36-47. [PMID: 22055855 DOI: 10.1016/j.mri.2011.09.010] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Revised: 08/03/2011] [Accepted: 09/13/2011] [Indexed: 11/16/2022]
Abstract
Functional magnetic resonance imaging (fMRI) at high magnetic field strength can suffer from serious degradation of image quality because of motion and physiological noise, as well as spatial distortions and signal losses due to susceptibility effects. Overcoming such limitations is essential for sensitive detection and reliable interpretation of fMRI data. These issues are particularly problematic in studies of awake animals. As part of our initial efforts to study functional brain activations in awake, behaving monkeys using fMRI at 4.7 T, we have developed acquisition and analysis procedures to improve image quality with encouraging results. We evaluated the influence of two main variables on image quality. First, we show how important the level of behavioral training is for obtaining good data stability and high temporal signal-to-noise ratios. In initial sessions, our typical scan session lasted 1.5 h, partitioned into short (<10 min) runs. During reward periods and breaks between runs, the monkey exhibited movements resulting in considerable image misregistrations. After a few months of extensive behavioral training, we were able to increase the length of individual runs and the total length of each session. The monkey learned to wait until the end of a block for fluid reward, resulting in longer periods of continuous acquisition. Each additional 60 training sessions extended the duration of each session by 60 min, culminating, after about 140 training sessions, in sessions that last about 4 h. As a result, the average translational movement decreased from over 500 μm to less than 80 μm, a displacement close to that observed in anesthetized monkeys scanned in a 7-T horizontal scanner. Another major source of distortion at high fields arises from susceptibility variations. To reduce such artifacts, we used segmented gradient-echo echo-planar imaging (EPI) sequences. Increasing the number of segments significantly decreased susceptibility artifacts and image distortion. Comparisons of images from functional runs using four segments with those using a single-shot EPI sequence revealed a roughly twofold improvement in functional signal-to-noise-ratio and 50% decrease in distortion. These methods enabled reliable detection of neural activation and permitted blood-oxygenation-level-dependent-based mapping of early visual areas in monkeys using a volume coil. In summary, both extensive behavioral training of monkeys and application of segmented gradient-echo EPI sequence improved signal-to-noise ratio and image quality. Understanding the effects these factors have is important for the application of high field imaging methods to the detection of submillimeter functional structures in the awake monkey brain.
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Affiliation(s)
- Gang Chen
- Department of Psychology, Vanderbilt University, Nashville, TN 37203, USA
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18
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Lau C, Zhou IY, Cheung MM, Chan KC, Wu EX. BOLD temporal dynamics of rat superior colliculus and lateral geniculate nucleus following short duration visual stimulation. PLoS One 2011; 6:e18914. [PMID: 21559482 PMCID: PMC3084720 DOI: 10.1371/journal.pone.0018914] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2010] [Accepted: 03/24/2011] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND The superior colliculus (SC) and lateral geniculate nucleus (LGN) are important subcortical structures for vision. Much of our understanding of vision was obtained using invasive and small field of view (FOV) techniques. In this study, we use non-invasive, large FOV blood oxygenation level-dependent (BOLD) fMRI to measure the SC and LGN's response temporal dynamics following short duration (1 s) visual stimulation. METHODOLOGY/PRINCIPAL FINDINGS Experiments are performed at 7 tesla on Sprague Dawley rats stimulated in one eye with flashing light. Gradient-echo and spin-echo sequences are used to provide complementary information. An anatomical image is acquired from one rat after injection of monocrystalline iron oxide nanoparticles (MION), a blood vessel contrast agent. BOLD responses are concentrated in the contralateral SC and LGN. The SC BOLD signal measured with gradient-echo rises to 50% of maximum amplitude (PEAK) 0.2±0.2 s before the LGN signal (p<0.05). The LGN signal returns to 50% of PEAK 1.4±1.2 s before the SC signal (p<0.05). These results indicate the SC signal rises faster than the LGN signal but settles slower. Spin-echo results support these findings. The post-MION image shows the SC and LGN lie beneath large blood vessels. This subcortical vasculature is similar to that in the cortex, which also lies beneath large vessels. The LGN lies closer to the large vessels than much of the SC. CONCLUSIONS/SIGNIFICANCE The differences in response timing between SC and LGN are very similar to those between deep and shallow cortical layers following electrical stimulation, which are related to depth-dependent blood vessel dilation rates. This combined with the similarities in vasculature between subcortex and cortex suggest the SC and LGN timing differences are also related to depth-dependent dilation rates. This study shows for the first time that BOLD responses in the rat SC and LGN following short duration visual stimulation are temporally different.
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Affiliation(s)
- Condon Lau
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Pokfulam, Hong Kong, Special Administrative Region, China
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong, Special Administrative Region, China
| | - Iris Y. Zhou
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Pokfulam, Hong Kong, Special Administrative Region, China
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong, Special Administrative Region, China
| | - Matthew M. Cheung
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Pokfulam, Hong Kong, Special Administrative Region, China
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong, Special Administrative Region, China
| | - Kevin C. Chan
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Pokfulam, Hong Kong, Special Administrative Region, China
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong, Special Administrative Region, China
| | - Ed X. Wu
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Pokfulam, Hong Kong, Special Administrative Region, China
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong, Special Administrative Region, China
- Department of Anatomy, The University of Hong Kong, Pokfulam, Hong Kong, Special Administrative Region, China
- Department of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, Special Administrative Region, China
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19
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Silva AC, Liu JV, Hirano Y, Leoni RF, Merkle H, Mackel JB, Zhang XF, Nascimento GC, Stefanovic B. Longitudinal functional magnetic resonance imaging in animal models. Methods Mol Biol 2011; 711:281-302. [PMID: 21279608 PMCID: PMC4748954 DOI: 10.1007/978-1-61737-992-5_14] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Functional magnetic resonance imaging (fMRI) has had an essential role in furthering our understanding of brain physiology and function. fMRI techniques are nowadays widely applied in neuroscience research, as well as in translational and clinical studies. The use of animal models in fMRI studies has been fundamental in helping elucidate the mechanisms of cerebral blood-flow regulation, and in the exploration of basic neuroscience questions, such as the mechanisms of perception, behavior, and cognition. Because animals are inherently non-compliant, most fMRI performed to date have required the use of anesthesia, which interferes with brain function and compromises interpretability and applicability of results to our understanding of human brain function. An alternative approach that eliminates the need for anesthesia involves training the animal to tolerate physical restraint during the data acquisition. In the present chapter, we review these two different approaches to obtaining fMRI data from animal models, with a specific focus on the acquisition of longitudinal data from the same subjects.
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Affiliation(s)
- Afonso C Silva
- Cerebral Microcirculation Unit, Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA.
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20
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Stoewer S, Ku SP, Goense J, Steudel T, Logothetis NK, Duncan J, Sigala N. Frontoparietal activity with minimal decision and control in the awake macaque at 7 T. Magn Reson Imaging 2010; 28:1120-8. [DOI: 10.1016/j.mri.2009.12.024] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2009] [Revised: 12/16/2009] [Accepted: 12/21/2009] [Indexed: 10/19/2022]
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21
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Murnane KS, Howell LL. Development of an apparatus and methodology for conducting functional magnetic resonance imaging (fMRI) with pharmacological stimuli in conscious rhesus monkeys. J Neurosci Methods 2010; 191:11-20. [PMID: 20566353 PMCID: PMC2915932 DOI: 10.1016/j.jneumeth.2010.06.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2010] [Revised: 04/28/2010] [Accepted: 06/01/2010] [Indexed: 11/23/2022]
Abstract
Functional magnetic resonance imaging (fMRI) is a technique with significant potential to advance our understanding of multiple brain systems. However, when human subjects undergo fMRI studies they are typically conscious whereas pre-clinical fMRI studies typically utilize anesthesia, which complicates comparisons across studies. Therefore, we have developed an apparatus suitable for imaging conscious rhesus monkeys. In order to minimize subject stress and spatial motion, each subject was acclimated to the necessary procedures over several months. The effectiveness of this process was then evaluated, in fully trained subjects, by quantifying objective physiological measures. These physiological metrics were stable both within and across sessions and did not differ from when these same subjects were immobilized using standard primate handling procedures. Subject motion and blood oxygenation level dependent (BOLD) fMRI measurements were then evaluated by scanning subjects under three different conditions: the absence of stimulation, presentation of a visual stimulus, or administration of intravenous (i.v.) cocaine (0.3mg/kg). Spatial motion differed neither by condition nor along the three principal axes. In addition, maximum translational and rotational motion never exceeded one half of the voxel size (0.75 mm) or 1.5 degrees, respectively. Furthermore, the localization of changes in blood oxygenation closely matched those reported in previous studies using similar stimuli. These findings document the feasibility of fMRI data collection in conscious rhesus monkeys using these procedures and allow for the further study of the neural effects of psychoactive drugs.
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Affiliation(s)
- Kevin Sean Murnane
- Division of Neuroscience, Yerkes National Primate Research Center, Atlanta, GA USA
| | - Leonard Lee Howell
- Division of Neuroscience, Yerkes National Primate Research Center, Atlanta, GA USA
- Department of Psychiatry and Behavioral Sciences, Emory University, Atlanta, GA, USA
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22
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Functional magnetic resonance imaging of awake behaving macaques. Methods 2010; 50:178-88. [DOI: 10.1016/j.ymeth.2009.08.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2009] [Accepted: 08/09/2009] [Indexed: 11/19/2022] Open
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23
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Srihasam K, Sullivan K, Savage T, Livingstone MS. Noninvasive functional MRI in alert monkeys. Neuroimage 2010; 51:267-73. [PMID: 20116433 DOI: 10.1016/j.neuroimage.2010.01.082] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2009] [Revised: 12/24/2009] [Accepted: 01/22/2010] [Indexed: 11/26/2022] Open
Abstract
Functional magnetic resonance imaging (fMRI) is now widely used to study human brain function. Alert monkey fMRI experiments have been used to localize functions and to compare the workings of the human and monkey brains. Monkey fMRI poses considerable challenges because of the monkey's small brain and naturally uncooperative disposition. While training can encourage monkeys to be more obliging during scanning, the usual procedure is to hold the monkey's head motionless by means of a surgically implanted head post. Such implants are invasive and require regular maintenance. In order to overcome these problems we developed a technique for holding monkeys' heads motionless during scanning using a custom-fitted plastic helmet, a chin strap, and a mild suction supplied by a vacuum blower. This vacuum helmet method is totally noninvasive and has shown no adverse effects after repeated use for several months. The motion of a trained monkey's head in the helmet during scanning was comparable to that of a trained monkey implanted with a conventional head post.
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Affiliation(s)
- Krishna Srihasam
- Department of Neurobiology, Harvard Medical School, 220 Longwood Ave., Boston, MA 02115, USA
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24
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Rilling JK. Neuroscientific approaches and applications within anthropology. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2009; Suppl 47:2-32. [PMID: 19003891 DOI: 10.1002/ajpa.20947] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Many of the most distinctive attributes of our species are a product of our brains. To understand the function, development, variability, and evolution of the human brain, we must engage with the field of neuroscience. Neuroscientific methods can be used to investigate research topics that are of special interest to anthropologists, such as the neural bases of primate behavioral diversity, human brain evolution, and human brain development. Traditional neuroscience methods had to rely on investigation of postmortem brains, as well as invasive studies in living nonhuman primates. However, recent neuroimaging methods have made it possible to compare living human and nonhuman primate brains using noninvasive techniques such as structural and functional magnetic resonance imaging, positron emission tomography, and diffusion tensor imaging. These methods are providing an integrated picture of brain structure and function that was not previously available. With a combination of these traditional and modern neuroscience methods, we are beginning to explore and understand the neural bases of some of the most distinctive cognitive and behavioral attributes of the human species, including language, tool use, altruism, and mental self-projection, and we can now begin to propose plausible scenarios by which the neural substrates supporting these human specializations evolved from pre-existing neural circuitry serving related functions in common ancestors we shared with the living nonhuman primates. Consideration of the process of neurodevelopment suggests plausible mechanisms by which the highly encephalized human brain might have evolved. Neurodevelopmental studies also demonstrate that experience can shape both brain structure and function, providing a mechanism by which people of different cultures learn to act and think differently. Finally, not only can anthropologists benefit from neuroscience, neuroscience can benefit from the more sophisticated concept of evolution that anthropology offers, including an appreciation of evolutionary diversity as well as consideration of the process by which the human brain was formed during evolution.
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Affiliation(s)
- James K Rilling
- Department of Anthropology, Emory University, Atlanta, GA 30322, USA.
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25
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Nader MA, Czoty PW. Brain Imaging in Nonhuman Primates: Insights into Drug Addiction. ILAR J 2008; 49:89-102. [DOI: 10.1093/ilar.49.1.89] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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26
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Oeltermann A, Ku SP, Logothetis NK. A novel functional magnetic resonance imaging compatible search-coil eye-tracking system. Magn Reson Imaging 2007; 25:913-22. [PMID: 17482787 DOI: 10.1016/j.mri.2007.02.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/11/2007] [Indexed: 10/23/2022]
Abstract
Measuring eye movements (EMs) using the search-coil eye-tracking technique is superior to video-based infrared methods [Collewijn H, van der Mark F, Jansen TC. Precise recording of human eye movements. Vision Res 1975;15(3):447-50], which suffer from the instability of pupil size, blinking behavior and lower temporal resolution. However, no conventional functional magnetic resonance imaging (fMRI)-compatible search-coil eye tracker exists. The main problems for such a technique are the interaction between the transmitter coils and the magnetic gradients used for imaging as well as the limited amount of space in a scanner. Here we present an approach to overcome these problems and we demonstrate a method to record EMs in an MRI scanner using a search coil. The system described has a spatial resolution of 0.07 degrees (visual angle) and a high temporal resolution (22 kHz). The transmitter coils are integrated into the visual presentation system and the control/analysis unit is portable, which enables us to integrate the eye tracker with an MRI scanner. Our tests demonstrate low noise in the recorded eye traces and scanning with minimal artifact. Furthermore, the induced current in the search coil caused by the RF pulses does not lead to measurable heating. Altogether, this MR-compatible search-coil eye tracker can be used to precisely monitor EMs with high spatial and temporal resolution during fMRI. It can therefore be of great importance for studies requiring accurate fixation of a target, or measurement and study of the subject's oculomotor system.
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Affiliation(s)
- Axel Oeltermann
- Max Planck Institute for Biological Cybernetics, 72076 Tuebingen, Germany.
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27
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Keliris GA, Shmuel A, Ku SP, Pfeuffer J, Oeltermann A, Steudel T, Logothetis NK. Robust controlled functional MRI in alert monkeys at high magnetic field: effects of jaw and body movements. Neuroimage 2007; 36:550-70. [PMID: 17509896 DOI: 10.1016/j.neuroimage.2007.02.057] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2006] [Revised: 02/09/2007] [Accepted: 02/27/2007] [Indexed: 11/30/2022] Open
Abstract
The use of functional magnetic resonance imaging (fMRI) in alert non-human primates is of great potential for research in systems neuroscience. It can be combined with invasive techniques and afford better understanding of non-invasively acquired brain imaging signals in humans. However, the difficulties in optimal application of alert monkey fMRI are multi-faceted, especially at high magnetic fields where the effects of motion and of changes in B0 are greatly amplified. To overcome these difficulties, strict behavioral controls and elaborate animal-training are needed. Here, we introduce a number of hardware developments, quantify the effect of movements on fMRI data, and present procedures for animal training and scanning for well-controlled and artifact-reduced alert monkey fMRI at high magnetic field. In particular, we describe systems for monitoring jaw and body movements, and for accurately tracking eye movements. A link between body and jaw movement and MRI image artifacts is established, showing that relying on the immobilization of an animal's head is not sufficient for high-quality imaging. Quantitative analysis showed that body and jaw movement events caused large instabilities in fMRI time series. On average, body movement events caused larger instabilities than jaw movement events. Residual baseline brain image position and signal amplitude shifts were observed after the jaw and body movement events ended. Based on these findings, we introduce a novel behavioral paradigm that relies on training the monkeys to stay still during long trials. A corresponding analysis method discards all data that were not obtained during the movement-free periods. The baseline position and amplitude shifts are overcome by motion correction and trial-by-trial signal normalization. The advantages of the presented method over conventional scanning and analysis are demonstrated with data obtained at 7 T. It is anticipated that the techniques presented here will prove useful for alert monkey fMRI at any magnetic field.
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Affiliation(s)
- Georgios A Keliris
- Max Planck Institute for Biological Cybernetics, Spemannstr. 38, 72076 Tuebingen, Germany
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28
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Padberg J, Krubitzer L. Thalamocortical connections of anterior and posterior parietal cortical areas in New World titi monkeys. J Comp Neurol 2006; 497:416-35. [PMID: 16736469 DOI: 10.1002/cne.21005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We examined the thalamocortical connections of electrophysiologically identified locations in the hand and forelimb representations in areas 3b, 1, and 5 in the New World titi monkeys (Callicebus moloch), and of area 7b/AIP. Labeled cells and terminals in the thalamus resulting from the injections were related to architectonic boundaries. As in previous studies in primates, the hand representation of area 3b has dense, restricted projections predominantly from the lateral division of the ventral posterior nucleus (VPl). Projections to area 1 were highly convergent from several thalamic nuclei including the ventral lateral nucleus (VL), anterior pulvinar (PA), VPl, and the superior division of the ventral posterior nucleus (VPs). In cortex immediately caudal to area 1, what we term area 5, thalamocortical connections were also highly convergent and predominantly from nuclei of the thalamus associated with motor, visual, or somatic processing such as VL, the medial pulvinar (PM), and PA, respectively; with moderate projections from VP, central lateral nucleus (CL), lateral posterior nucleus (LP), and VPs. Finally, thalamocortical connections of area 7b/AIP were from a range of nuclei including PA, PM, LP/LD, VL, CL, PL, and CM. The current data support two conclusions drawn from previous studies in titi monkeys and other primates. First, cortex caudal to area 1 in New World monkeys is more like area 5 than area 2. Second, the presence of thalamic input to area 5 from both motor nuclei and somatosensory nuclei of the thalamus, suggests that area 5 could be considered a highly specialized sensorimotor area.
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Affiliation(s)
- Jeffrey Padberg
- Center for Neuroscience and Department of Psychology, University of California-Davis, Davis, California 95616, USA
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Gamlin PD, Ward MK, Bolding MS, Grossmann JK, Twieg DB. Developing functional magnetic resonance imaging techniques for alert macaque monkeys. Methods 2006; 38:210-20. [PMID: 16481198 DOI: 10.1016/j.ymeth.2005.08.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/15/2005] [Indexed: 12/30/2022] Open
Abstract
Functional magnetic resonance imaging (fMRI) has developed rapidly into a major non-invasive tool for studying the human brain. However, due to a variety of technical difficulties, it has yet to be widely adopted for use in alert, trained non-human primates. Our laboratory has been developing techniques for such fMRI studies. As background, we first consider basic principles of fMRI imaging, experimental design, and post-processing. We discuss appropriate MRI system hardware and components for conducting fMRI studies in alert macaques, and the animal preparation and behavior necessary for optimal experiments. Finally, we consider alternative fMRI techniques using exogenous contrast agents, arterial spin labeling, and more direct measures of neural activation.
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Affiliation(s)
- Paul D Gamlin
- Department of Vision Sciences, Center for the Development of Functional Imaging, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
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Joseph JE, Powell DK, Andersen AH, Bhatt RS, Dunlap MK, Foldes ST, Forman E, Hardy PA, Steinmetz NA, Zhang Z. fMRI in alert, behaving monkeys: an adaptation of the human infant familiarization novelty preference procedure. J Neurosci Methods 2006; 157:10-24. [PMID: 16675025 DOI: 10.1016/j.jneumeth.2006.03.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2005] [Revised: 03/21/2006] [Accepted: 03/24/2006] [Indexed: 11/30/2022]
Abstract
Functional magnetic resonance imaging (fMRI) is increasingly used in non-human primate research. In the present study, we adapt the familiarization-novelty preference (FNP) procedure used in human infant research to examine visual behavior in alert, unanaesthetized rhesus monkeys that were acclimated to the fMRI environment, but did not undergo behavioral training. In keeping with the typical FNP paradigm, we recorded eye movements (looking time and number of fixations) while monkeys viewed a series of four identical pictures (familiarization phase) followed by two different pictures (novelty phase). Number of fixations and looking time both increased during the novelty phase, thereby demonstrating visual discrimination of the new from the old picture. Importantly, discrimination did not occur on catch trials in which six identical pictures were presented. Moreover, brain activation in the amygdala was more strongly associated with the novelty phase than with the familiarization phase. In addition, magnitude of brain activation in the amygdala was correlated with the behavioral effect of visual discrimination. These findings demonstrate the feasibility of using eye movements as an index of visual discrimination in untrained monkeys during fMRI scanning. This methodological approach helps to extend the repertoire of research tools for fMRI in non-human primates.
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Affiliation(s)
- Jane E Joseph
- Department of Anatomy and Neurobiology, University of Kentucky, Lexington, KY, USA.
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31
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Ferris CF, Febo M, Luo F, Schmidt K, Brevard M, Harder JA, Kulkarni P, Messenger T, King JA. Functional magnetic resonance imaging in conscious animals: a new tool in behavioural neuroscience research. J Neuroendocrinol 2006; 18:307-18. [PMID: 16629829 PMCID: PMC1448699 DOI: 10.1111/j.1365-2826.2006.01424.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- C F Ferris
- Center for Comparative Neuroimaging, Department of Psychiatry, University of Massachusetts Medical School, Worcester, MA 01655, USA.
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32
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Raz A, Lieber B, Soliman F, Buhle J, Posner J, Peterson BS, Posner MI. Ecological nuances in functional magnetic resonance imaging (fMRI): psychological stressors, posture, and hydrostatics. Neuroimage 2005; 25:1-7. [PMID: 15734338 DOI: 10.1016/j.neuroimage.2004.11.015] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2004] [Revised: 11/09/2004] [Accepted: 11/10/2004] [Indexed: 11/22/2022] Open
Abstract
Brain imaging techniques such as functional magnetic resonance imaging (fMRI) have forged an impressive link between psychology and neuroscience. Whereas most experiments in cognitive psychology require participants to perform while sitting upright in front of display devices, fMRI obliges participants to perform cognitive tasks while lying supine and motionless inside a narrow bore. In addition to introducing psychological and physical stressors, such as loud thumps and head restraints, fMRI procedures also alter brain hydrostatics. The ecological factors associated with current fMRI technology, such as supine posture, may skew cognitive processing and influence hemodynamic and electrophysiological measurements, especially in extreme age groups and pathological populations. Recognizing the central role of fMRI in unraveling the neural mechanisms of cognition, we outline ways to address these limitations.
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Affiliation(s)
- Amir Raz
- MRI Unit, Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York State Psychiatric Institute, 1051 Riverside Drive, Box 74, New York, NY 10032, USA.
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Austin VC, Blamire AM, Allers KA, Sharp T, Styles P, Matthews PM, Sibson NR. Confounding effects of anesthesia on functional activation in rodent brain: a study of halothane and α-chloralose anesthesia. Neuroimage 2005; 24:92-100. [PMID: 15588600 DOI: 10.1016/j.neuroimage.2004.08.011] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2004] [Revised: 08/09/2004] [Accepted: 08/10/2004] [Indexed: 11/29/2022] Open
Abstract
Functional magnetic resonance imaging (fMRI) in animal models provides a platform for more extensive investigation of drug effects and underlying physiological mechanisms than is possible in humans. However, it is usually necessary for the animal to be anesthetized. In this study, we have used a rat model of direct cortical stimulation to investigate the effects of anesthesia in rodent fMRI. Specifically, we have sought to answer two questions (i) what is the relationship between baseline neuronal activity and the BOLD response to stimulation under halothane anesthesia? And (ii) how does the BOLD response change after transferring from halothane to the commonly used anesthetic alpha-chloralose? In the first set of experiments, we found no significant differences in the amplitude of the BOLD response at the different halothane doses studied, despite electroencephalography (EEG) recordings indicating a dose-dependent reduction in baseline neuronal activity with increasing halothane levels. In the second set of experiments, a reduction in the spatial extent of the BOLD response was apparent immediately after transfer from halothane to alpha-chloralose anesthesia, although no change in the peak signal change was evident. However, several hours after transfer to alpha-chloralose, a significant increase in both the spatial extent and peak height of the BOLD response was observed, as well as an increased sensitivity to secondary cortical and subcortical activation. These findings suggest that, although alpha-chloralose anesthesia is associated with a greater BOLD response for a fixed stimulus relative to halothane, there is substantial variation in the extent and magnitude of the response over time that could introduce considerable variability in studies using this anesthetic.
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Affiliation(s)
- V C Austin
- Experimental Neuroimaging Group, Department of Biochemistry, University of Oxford, Oxford, UK
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34
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Pinsk MA, Moore T, Richter MC, Gross CG, Kastner S. Methods for functional magnetic resonance imaging in normal and lesioned behaving monkeys. J Neurosci Methods 2004; 143:179-95. [PMID: 15814151 DOI: 10.1016/j.jneumeth.2004.10.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2004] [Revised: 10/06/2004] [Accepted: 10/06/2004] [Indexed: 11/26/2022]
Abstract
Methods for performing functional magnetic resonance imaging (fMRI) studies in behaving and lesioned monkeys using a human MR scanner are reported. Materials for head implant surgery were selected based on tests for magnetic susceptibility. A primate chair with a rigid head fixation system and a mock scanner environment for training were developed. To perform controlled visual studies, monkeys were trained to maintain fixation for several minutes using a novel training technique that utilized continuous juice rewards. A surface coil was used to acquire anatomical and functional images in four monkeys, one with a partial lesion of striate cortex. High-resolution anatomical images were used after non-uniform intensity correction to create cortical surface reconstructions of both lesioned and normal hemispheres. Our methods were confirmed in two visual experiments, in which functional activations were obtained during both free viewing and fixation conditions. In one experiment, face-selective activity was found in the fundus and banks of the superior temporal sulcus and the middle temporal gyrus in monkeys viewing pictures of faces and objects while maintaining fixation. In a second experiment, regions in occipital, parietal, and frontal cortex were activated in lesioned and normal animals viewing a cartoon movie. Importantly, in the animal with the striate lesion, fMRI signals were obtained in the immediate vicinity of the lesion. Our results extend those previously reported by providing a detailed account of the technique and by demonstrating the feasibility of fMRI in monkeys with lesions.
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Affiliation(s)
- Mark A Pinsk
- Department of Psychology, Princeton University, Green Hall, NJ 08544, USA
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Tenney JR, Marshall PC, King JA, Ferris CF. fMRI of generalized absence status epilepticus in conscious marmoset monkeys reveals corticothalamic activation. Epilepsia 2004; 45:1240-7. [PMID: 15461678 DOI: 10.1111/j.0013-9580.2004.21504.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE A nonhuman primate model of generalized absence status epilepticus was developed for use in functional magnetic resonance imaging (fMRI) experiments to elucidate the brain mechanisms underlying this disorder. METHODS Adult male marmoset monkeys (Callithrix jacchus) were treated with gamma-butyrolactone (GBL) to induce prolonged absence seizures, and the resulting spike-wave discharges (SWDs) were analyzed to determine the similarity to the 3-Hz SWDs that characterize the disorder. In addition, blood-oxygenation-level-dependent (BOLD) fMRI was measured at 4.7 Tesla after absence seizure induction with GBL. RESULTS Electroencephalographic recordings during imaging showed 3-Hz SWDs typical of human absence seizures. This synchronized EEG pattern started within 15 to 20 min of drug administration and persisted for >60 min. In addition, pretreatment with the antiepileptic drug, ethosuximide (ESM), blocked the behavioral and EEG changes caused by GBL. Changes in BOLD signal intensity in the thalamus and sensorimotor cortex correlated with the onset of 3-Hz SWDs. The change in BOLD signal intensity was bilateral but heterogeneous, affecting some brain areas more than others. No significant negative BOLD changes were seen. CONCLUSIONS The BOLD fMRI data obtained in this marmoset monkey model of absence status epilepticus shows activation within the thalamus and cortex.
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Affiliation(s)
- Jeffrey R Tenney
- Center for Comparative Neuroimaging, Department of Psychiatry, University of Massachusetts Medical School, Worcester, Massachusetts, USA.
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36
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Schulz M, Chau W, Graham SJ, McIntosh AR, Ross B, Ishii R, Pantev C. An integrative MEG-fMRI study of the primary somatosensory cortex using cross-modal correspondence analysis. Neuroimage 2004; 22:120-33. [PMID: 15110002 DOI: 10.1016/j.neuroimage.2003.10.049] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2003] [Revised: 10/16/2003] [Accepted: 10/22/2003] [Indexed: 11/19/2022] Open
Abstract
We develop a novel approach of cross-modal correspondence analysis (CMCA) to address whether brain activities observed in magnetoencephalography (MEG) and functional magnetic resonance imaging (fMRI) represent a common neuronal subpopulation, and if so, which frequency band obtained by MEG best fits the common brain areas. Fourteen adults were investigated by whole-head MEG using a single equivalent current dipole (ECD) and synthetic aperture magnetometry (SAM) approaches and by fMRI at 1.5 T using linear time-invariant modeling to generate statistical maps. The same somatosensory stimulus sequences consisting of tactile impulses to the right sided: digit 1, digit 4 and lower lip were used in both neuroimaging modalities. To evaluate the reproducibility of MEG and fMRI results, one subject was measured repeatedly. Despite different MEG dipole locations and locations of maximum activation in SAM and fMRI, CMCA revealed a common subpopulation of the primary somatosensory cortex, which displays a clear homuncular organization. MEG activity in the frequency range between 30 and 60 Hz, followed by the ranges of 20-30 and 60-100 Hz, explained best the defined subrepresentation given by both MEG and fMRI. These findings have important implications for improving and understanding of the biophysics underlying both neuroimaging techniques, and for determining the best strategy to combine MEG and fMRI data to study the spatiotemporal nature of brain activity.
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Affiliation(s)
- Matthias Schulz
- Institute for Biomagnetism and Biosignalanalysis, Münster University Hospital, University of Münster, Kardinal-von-Galen-Ring 10, 48129 Münster, Germany
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37
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Abstract
PURPOSE EEG-triggered functional magnetic resonance imaging (fMRI) was used to identify areas of brain activation during spontaneous spike-and-wave discharges (SWDs) in an epileptic rat strain under awake conditions. METHODS Spontaneous absence seizures from 10 WAG/Rij rats were imaged by using T2*-weighted echo planar imaging at 4.7 Tesla. fMRI of the blood-oxygenation-level-dependent (BOLD) signal was triggered based on EEG recordings during imaging. Images obtained during spontaneous SWDs were compared with baseline images. RESULTS Significant positive BOLD signal changes were apparent in several areas of the cortex and several important nuclei of the thalamus. In addition, no negative BOLD signal was found in any brain area. CONCLUSIONS We have shown that EEG-triggered BOLD fMRI can be used to detect cortical and thalamic activation related to the spontaneous SWDs that characterize absence seizures in awake WAG/Rij rats. These results draw an anatomic correlation between areas in which increased BOLD signal is found and those in which SWDs have been recorded. In addition, no negative BOLD signal was found to be associated with these spontaneous SWDs. We also demonstrated the technical feasibility of using EEG-triggered fMRI in a genetic rat model of absence seizure.
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Affiliation(s)
- Jeffrey R Tenney
- Center for Comparative Neuroimaging, Department of Psychiatry, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA.
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38
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Koyama M, Hasegawa I, Osada T, Adachi Y, Nakahara K, Miyashita Y. Functional Magnetic Resonance Imaging of Macaque Monkeys Performing Visually Guided Saccade Tasks. Neuron 2004; 41:795-807. [PMID: 15003178 DOI: 10.1016/s0896-6273(04)00047-9] [Citation(s) in RCA: 239] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2003] [Revised: 12/02/2003] [Accepted: 01/20/2004] [Indexed: 11/30/2022]
Abstract
The frontal and parietal eye fields serve as functional landmarks of the primate brain, although their correspondences between humans and macaque monkeys remain unclear. We conducted fMRI at 4.7 T in monkeys performing visually-guided saccade tasks and compared brain activations with those in humans using identical paradigms. Among multiple parietal activations, the dorsal lateral intraparietal area in monkeys and an area in the posterior superior parietal lobule in humans exhibited the highest selectivity to saccade directions. In the frontal cortex, the selectivity was highest at the junction of the precentral and superior frontal sulci in humans and in the frontal eye field (FEF) in monkeys. BOLD activation peaks were also found in premotor areas (BA6) in monkeys, which suggests that the apparent discrepancy in location between putative human FEF (BA6, suggested by imaging studies) and monkey FEF (BA8, identified by microstimulation studies) partly arose from methodological differences.
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Affiliation(s)
- Minoru Koyama
- Department of Physiology, The University of Tokyo School of Medicine, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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39
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Dubowitz DJ. Direct Comparison of Visual Cortex Activation in Human and Nonhuman Primates Using Functional Magnetic Resonance Imaging. Methods Enzymol 2004; 385:102-34. [PMID: 15130736 DOI: 10.1016/s0076-6879(04)85007-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Affiliation(s)
- David J Dubowitz
- Department of Radiology, Center for Functional Magnetic Resonance Imaging, University of California-San Diego, La Jolla, CA 92093-0677, USA
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40
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Nakahara K. Functional Magnetic Resonance Imaging of Macaque Monkeys. Methods Enzymol 2004; 385:84-90. [PMID: 15130734 DOI: 10.1016/s0076-6879(04)85005-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Affiliation(s)
- Kiyoshi Nakahara
- Department of Physiology, The University of Tokyo School of Medicine, Tokyo 113-0033, Japan
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41
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Boyett-Anderson JM, Lyons DM, Reiss AL, Schatzberg AF, Menon V. Functional brain imaging of olfactory processing in monkeys. Neuroimage 2003; 20:257-64. [PMID: 14527586 DOI: 10.1016/s1053-8119(03)00288-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
As a step toward bridging the gap between human and animal studies of olfactory brain systems, we report results from an fMRI study of olfaction in squirrel monkeys. High-resolution fMRI images at 3 T with 1.25 x 1.25 x 1.2 mm(3) voxels were obtained covering the whole brain using an 8-cm-diameter birdcage coil and a gradient-echo spiral pulse sequence. Data were acquired from six sedated adult males using a standard block design. All fMRI data were spatially normalized to a common template and analyzed at the individual and group levels with statistical parametric and nonparametric methods. Robust odorant-induced activations were detected in several brain regions previously implicated in conscious human olfactory processing, including the orbitofrontal cortex, cerebellum, and piriform cortex. Consistent with human data, no stimulus intensity effects were observed in any of these regions. Average signal changes in these regions exceeded 0.6%, more than three times the expected signal change based on human fMRI studies of olfaction adjusting for differences in voxel size. These results demonstrate the feasibility of studying olfaction in sedated monkeys with imaging techniques commonly used at 3 T in humans and help promote direct comparisons between humans and nonhuman primates. Our findings, for example, provide novel support for the hypothesis that the cerebellum is involved in sensory acquisition. More broadly, this study suggests that olfactory processing in sedated monkeys and nonsedated humans shares similar neural substrates both within and beyond the primary olfactory system.
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Affiliation(s)
- J M Boyett-Anderson
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA 94305, USA
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42
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Tenney JR, Duong TQ, King JA, Ludwig R, Ferris CF. Corticothalamic modulation during absence seizures in rats: a functional MRI assessment. Epilepsia 2003; 44:1133-40. [PMID: 12919383 PMCID: PMC2962948 DOI: 10.1046/j.1528-1157.2003.61002.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE Functional magnetic resonance imaging (fMRI) was used to identify areas of brain activation during absence seizures in an awake animal model. METHODS Blood-oxygenation-level-dependent (BOLD) fMRI in the brain was measured by using T2*-weighted echo planar imaging at 4.7 Tesla. BOLD imaging was performed before, during, and after absence seizure induction by using gamma-butyrolactone (GBL; 200 mg/kg, intraperitoneal). RESULTS The corticothalamic circuitry, critical for spike-wave discharge (SWD) formation in absence seizure, showed robust BOLD signal changes after GBL administration, consistent with EEG recordings in the same animals. Predominantly positive BOLD changes occurred in the thalamus. Sensory and parietal cortices showed mixed positive and negative BOLD changes, whereas temporal and motor cortices showed only negative BOLD changes. CONCLUSIONS With the BOLD fMRI technique, we demonstrated signal changes in brain areas that have been shown, with electrophysiology experiments, to be important for generating and maintaining the SWDs that characterize absence seizures. These results corroborate previous findings from lesion and electrophysiological experiments and show the technical feasibility of noninvasively imaging absence seizures in fully conscious rodents.
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Affiliation(s)
- Jeffrey R Tenney
- Center for Comparative Neuroimaging, Department of Psychiatry, University of Massachusetts Medical School Worcester, Massachusetts 01655, USA.
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Tsao DY, Freiwald WA, Knutsen TA, Mandeville JB, Tootell RBH. Faces and objects in macaque cerebral cortex. Nat Neurosci 2003; 6:989-95. [PMID: 12925854 PMCID: PMC8117179 DOI: 10.1038/nn1111] [Citation(s) in RCA: 438] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2003] [Accepted: 06/18/2003] [Indexed: 11/09/2022]
Abstract
How are different object categories organized by the visual system? Current evidence indicates that monkeys and humans process object categories in fundamentally different ways. Functional magnetic resonance imaging (fMRI) studies suggest that humans have a ventral temporal face area, but such evidence is lacking in macaques. Instead, face-responsive neurons in macaques seem to be scattered throughout temporal cortex, with some relative concentration in the superior temporal sulcus (STS). Here, using fMRI in alert fixating macaque monkeys and humans, we found that macaques do have discrete face-selective patches, similar in relative size and number to face patches in humans. The face patches were embedded within a large swath of object-selective cortex extending from V4 to rostral TE. This large region responded better to pictures of intact objects compared to scrambled objects, with different object categories eliciting different patterns of activity, as in the human. Overall, our results suggest that humans and macaques share a similar brain architecture for visual object processing.
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Affiliation(s)
- Doris Y Tsao
- Athinoula A. Martinos Center, Charlestown, Massachusetts 02129, USA.
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44
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Orban GA, Fize D, Peuskens H, Denys K, Nelissen K, Sunaert S, Todd J, Vanduffel W. Similarities and differences in motion processing between the human and macaque brain: evidence from fMRI. Neuropsychologia 2003; 41:1757-68. [PMID: 14527539 DOI: 10.1016/s0028-3932(03)00177-5] [Citation(s) in RCA: 145] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The present report reviews a series of functional magnetic resonance imaging (fMRI) activation studies conducted in parallel in awake monkeys and humans using the same motion stimuli in both species. These studies reveal that motion stimuli engage largely similar cortical regions in the two species. These common regions include MT/V5 and its satellites, of which FST contributes more to the human motion complex than is generally assumed in human imaging. These results also establish a direct link between selectivity of MT/V5 neurons for speed gradients and functional activation of human MT/V5 by three-dimensional (3D) structure from motion stimuli. On the other hand, striking functional differences also emerged: in humans V3A and several regions in the intraparietal sulcus (IPS) are much more motion sensitive than their simian counterparts.
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Affiliation(s)
- Guy A Orban
- K.U. Leuven, Laboratorium voor Neuro- en Pyschofysiologie, Campus Gasthuisberg, Herestraat 49, B-3000 Leuven, Belgium
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45
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Vanduffel W, Fize D, Peuskens H, Denys K, Sunaert S, Todd JT, Orban GA. Extracting 3D from motion: differences in human and monkey intraparietal cortex. Science 2002; 298:413-5. [PMID: 12376701 DOI: 10.1126/science.1073574] [Citation(s) in RCA: 212] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
We compared three-dimensional structure-from-motion (3D-SFM) processing in awake monkeys and humans using functional magnetic resonance imaging. Occipital and midlevel extrastriate visual areas showed similar activation by 3D-SFM stimuli in both species. In contrast, intraparietal areas showed significant 3D-SFM activation in humans but not in monkeys. This suggests that human intraparietal cortex contains visuospatial processing areas that are not present in monkeys.
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Affiliation(s)
- W Vanduffel
- Laboratorium voor Neuro- en Psychofysiologie, Katholieke Universiteit Leuven, Campus Gasthuisberg, Herestraat 49, Leuven B-3000, Belgium.
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46
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Tabuchi E, Yokawa T, Mallick H, Inubushi T, Kondoh T, Ono T, Torii K. Spatio–temporal dynamics of brain activated regions during drinking behavior in rats. Brain Res 2002; 951:270-9. [PMID: 12270506 DOI: 10.1016/s0006-8993(02)03173-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Spatio-temporal dynamics of activated brain areas induced by drinking were investigated and visualized in behaving rats using functional magnetic resonance imaging (fMRI). The rats were trained to drink in the magnet bore, and the images were taken during and after drinking glucose and distilled water. During glucose ingestion, the signal intensity was increased continuously and maximally in the lateral hypothalamic area (LHA) and the ventromedial hypothalamus (VMH). Somewhat less intense activation in the central nucleus of the amygdala (AMc), and transient activation in the piriform cortex and the mediodorsal nucleus of the thalamus were observed. The signal intensities of other regions measured were largely unchanged. During post-ingestive periods, the signals re-increased in the hypothalamic areas and AMc. When water was given, LHA and VMH were similarly activated, however, the signal intensity in the amygdala was not significantly increased. The results indicate that these brain regions are activated differentially during drinking behavior, and that LHA and VMH play a central role in the control of not only feeding but also drinking. The regional activities in LHA and VMH are not principally related to the gustatory sensation, and the reactivation after drinking may be related to satisfaction or post-ingestive nutritional information. Also, the responses of AMc are probably due to reward value difference. To the best of our knowledge, this is the first report of mapping of brain areas using fMRI in behaving rats. The improved method described in this study for collecting fMRI data in behaving animals will be useful for studying functional network during animal behavior.
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Affiliation(s)
- Eiichi Tabuchi
- Torii Nutrient-stasis Project, Exploratory Research for Advanced Technology (ERATO), Research Development Corporation of Japan, Yokohama 221, Japan
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Abstract
We performed a series of functional magnetic resonance imaging experiments to divide the human MT+ complex into subregions that may be identified as homologs to a pair of macaque motion-responsive visual areas: the middle temporal area (MT) and the medial superior temporal area (MST). Using stimuli designed to tease apart differences in retinotopic organization and receptive field size, we established a double dissociation between two distinct MT+ subregions in 8 of the 10 hemispheres studied. The first subregion exhibited retinotopic organization but did not respond to peripheral ipsilateral stimulation, indicative of smaller receptive fields. Conversely, the second subregion within MT+ did not demonstrate retinotopic organization but did respond to peripheral stimuli in both the ipsilateral and contralateral visual hemifields, indicative of larger receptive fields. We tentatively identify these subregions as the human homologues of macaque MT and MST, respectively. Putative human MT and MST were typically located on the posterior/ventral and anterior/dorsal banks of a dorsal/posterior limb of the inferior temporal sulcus, similar to their relative positions in the macaque superior temporal sulcus.
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Andersen AH, Zhang Z, Barber T, Rayens WS, Zhang J, Grondin R, Hardy P, Gerhardt GA, Gash DM. Functional MRI studies in awake rhesus monkeys: methodological and analytical strategies. J Neurosci Methods 2002; 118:141-52. [PMID: 12204305 DOI: 10.1016/s0165-0270(02)00123-1] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Functional imaging of the non-human primate brain in awake animals is now feasible because of recent methodological advances. Here we detail our procedures for conducting functional MRI (fMRI) studies in rhesus monkeys. Our emphasis has been on analyzing drug-evoked responses within and across test groups, meaning that techniques have had to be developed for training and testing relatively large groups of animals. Group size is important as unbiased estimates are best derived from analyzing responses in multiple animals with replicate scans per animal due to partial volume errors in evaluating small brain regions and motion artifacts during scanning. While the procedures presented here were developed for mapping responses obtained from stimulating dopaminergic systems, much of the methodology is generally applicable for non-human primate fMRI studies and addresses specific problems encountered in imaging awake animals. These are (1) adapting animals to an MRI environment, (2) minimizing head movements, (3) reducing ambient scanning noise levels, and (4) developing multivariate methods of image data analysis suitable for eliciting the dynamic brain response while (5) detecting and deleting outlying observations due to motion artifacts. Procedures are demonstrated for first pre-processing and analyzing responses in a voxel-based approach in a single animal and then proceeding to analyze responses across animals and replicate scans for regions of interest. Collectively, the procedures described provide an approach for fMRI mapping of elicited responses using conventional 1.5T MR scanners.
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Affiliation(s)
- Anders H Andersen
- Department of Anatomy and Neurobiology, College of Medicine, University of Kentucky, 317 Davis Mills Building (MRISC), Lexington, KY 40536-0298, USA
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49
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Affiliation(s)
- Guy A Orban
- Laboratory of Neuro- and Psychophysiology, Medical School, Katholieke Universiteit Leuven, Campus Gasthuisberg, Herestraat 49, B-3000 Louvain, Belgium.
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50
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Leite FP, Tsao D, Vanduffel W, Fize D, Sasaki Y, Wald LL, Dale AM, Kwong KK, Orban GA, Rosen BR, Tootell RBH, Mandeville JB. Repeated fMRI using iron oxide contrast agent in awake, behaving macaques at 3 Tesla. Neuroimage 2002; 16:283-94. [PMID: 12030817 DOI: 10.1006/nimg.2002.1110] [Citation(s) in RCA: 192] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Iron oxide contrast agents have been employed extensively in anesthetized rodents to enhance fMRI sensitivity and to study the physiology of cerebral blood volume (CBV) in relation to blood oxygen level-dependent (BOLD) signal following neuronal activation. This study quantified the advantages of exogenous agent for repeated neuroimaging in awake, nonhuman primates using a clinical 3 Tesla scanner. A monocrystalline iron oxide nanoparticle (MION) solution was injected at iron doses of 8 to 10 mg/kg in two macaque monkeys. Adverse behavioral effects due to contrast agent were not observed in either monkey using cumulative doses in excess of 60 mg/kg. Relative to BOLD imaging at 3 Tesla, MION increased functional sensitivity by an average factor of 3 across the brain for a stimulus of long duration. Rapid stimulus presentation attenuated MION signal changes more than BOLD signal changes, due to the slower time constant of the blood volume response relative to BOLD signal. Overall, the contrast agent produced a dramatic improvement in functional brain imaging results in the awake, behaving primate at this field strength. (c) 2002 Elsevier Science (USA).
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Affiliation(s)
- Francisca P Leite
- Massachusetts Institute of Technology, Department of Nuclear Engineering, Cambridge, Massachusetts 02139, USA
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