1
|
Tatti E, Cacciola A, Carrara F, Luciani A, Quartarone A, Ghilardi MF. Movement-related ERS and connectivity in the gamma frequency decrease with practice. Neuroimage 2023; 284:120444. [PMID: 37926216 PMCID: PMC10758293 DOI: 10.1016/j.neuroimage.2023.120444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 10/30/2023] [Accepted: 11/03/2023] [Indexed: 11/07/2023] Open
Abstract
Previous work showed that movements are accompanied by modulation of electroencephalographic (EEG) activity in both beta (13-30 Hz) and gamma (>30 Hz) ranges. The amplitude of beta event-related synchronization (ERS) is not linked to movement characteristics, but progressively increases with motor practice, returning to baseline after a period of rest. Conversely, movement-related gamma ERS amplitude is proportional to movement distance and velocity. Here, high-density EEG was recorded in 51 healthy subjects to investigate whether i) three-hour practice in two learning tasks, one with a motor component and one without, affects gamma ERS amplitude and connectivity during a motor reaching test, and ii) 90-minutes of either sleep or quiet rest have an effect on gamma oscillatory activity. We found that, while gamma ERS was appropriately scaled to the target extent at all testing points, its amplitude decreased after practice, independently of the type of interposed learning, and after both quiet wake and nap, with partial correlations with subjective fatigue scores. During movement execution, connectivity patterns within fronto-parieto-occipital electrodes, over areas associated with attentional networks, decreased after both practice and after 90-minute rest. While confirming the prokinetic nature of movement-related gamma ERS, these findings demonstrated the preservation of gamma ERS scaling to movement velocity with practice, despite constant amplitude reduction. We thus speculate that such decreases, differently from the practice-related increases of beta ERS, are related to reduced attention or working memory mechanisms due to fatigue or a switch of strategy toward automatization of movement execution and do not specifically reflect plasticity phenomena.
Collapse
Affiliation(s)
- Elisa Tatti
- Department of Molecular, Cellular & Biomedical Sciences, CUNY, School of Medicine, New York, NY 10031, United States.
| | - Alberto Cacciola
- Brain Mapping Lab, Department of Biomedical, Dental Sciences and Morphological and Functional Images, University of Messina, Messina, Italy; Center for Complex Network Intelligence (CCNI), Tsinghua Laboratory of Brain and Intelligence (THBI), Tsinghua University, Beijing, China; Department of Biomedical Engineering, Tsinghua University, Beijing, China
| | - Federico Carrara
- Department of Mathematics, Polytechnic University of Milan, Piazza Leonardo da Vinci 32, 20133 Milan, Italy
| | - Adalgisa Luciani
- Department of Molecular, Cellular & Biomedical Sciences, CUNY, School of Medicine, New York, NY 10031, United States; Section of Psychiatry, Department of Neuroscience, School of Medicine, University of Naples "Federico II", Naples, Italy
| | - Angelo Quartarone
- IRCCS-Centro Neurolesi Bonino-Pulejo, S.S. 113, Via Palermo, C. da Casazza, 98124 Messina, Italy.
| | - M Felice Ghilardi
- Department of Molecular, Cellular & Biomedical Sciences, CUNY, School of Medicine, New York, NY 10031, United States.
| |
Collapse
|
2
|
Bidirectional alterations in brain temperature profoundly modulate spatiotemporal neurovascular responses in-vivo. Commun Biol 2023; 6:185. [PMID: 36797344 PMCID: PMC9935519 DOI: 10.1038/s42003-023-04542-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 01/31/2023] [Indexed: 02/18/2023] Open
Abstract
Neurovascular coupling (NVC) is a mechanism that, amongst other known and latent critical functions, ensures activated brain regions are adequately supplied with oxygen and glucose. This biological phenomenon underpins non-invasive perfusion-related neuroimaging techniques and recent reports have implicated NVC impairment in several neurodegenerative disorders. Yet, much remains unknown regarding NVC in health and disease, and only recently has there been burgeoning recognition of a close interplay with brain thermodynamics. Accordingly, we developed a novel multi-modal approach to systematically modulate cortical temperature and interrogate the spatiotemporal dynamics of sensory-evoked NVC. We show that changes in cortical temperature profoundly and intricately modulate NVC, with low temperatures associated with diminished oxygen delivery, and high temperatures inducing a distinct vascular oscillation. These observations provide novel insights into the relationship between NVC and brain thermodynamics, with important implications for brain-temperature related therapies, functional biomarkers of elevated brain temperature, and in-vivo methods to study neurovascular coupling.
Collapse
|
3
|
Zhang Q, Turner KL, Gheres KW, Hossain MS, Drew PJ. Behavioral and physiological monitoring for awake neurovascular coupling experiments: a how-to guide. NEUROPHOTONICS 2022; 9:021905. [PMID: 35639834 PMCID: PMC8802326 DOI: 10.1117/1.nph.9.2.021905] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 12/28/2021] [Indexed: 06/15/2023]
Abstract
Significance: Functional brain imaging in awake animal models is a popular and powerful technique that allows the investigation of neurovascular coupling (NVC) under physiological conditions. However, ubiquitous facial and body motions (fidgeting) are prime drivers of spontaneous fluctuations in neural and hemodynamic signals. During periods without movement, animals can rapidly transition into sleep, and the hemodynamic signals tied to arousal state changes can be several times larger than sensory-evoked responses. Given the outsized influence of facial and body motions and arousal signals in neural and hemodynamic signals, it is imperative to detect and monitor these events in experiments with un-anesthetized animals. Aim: To cover the importance of monitoring behavioral state in imaging experiments using un-anesthetized rodents, and describe how to incorporate detailed behavioral and physiological measurements in imaging experiments. Approach: We review the effects of movements and sleep-related signals (heart rate, respiration rate, electromyography, intracranial pressure, whisking, and other body movements) on brain hemodynamics and electrophysiological signals, with a focus on head-fixed experimental setup. We summarize the measurement methods currently used in animal models for detection of those behaviors and arousal changes. We then provide a guide on how to incorporate this measurements with functional brain imaging and electrophysiology measurements. Results: We provide a how-to guide on monitoring and interpreting a variety of physiological signals and their applications to NVC experiments in awake behaving mice. Conclusion: This guide facilitates the application of neuroimaging in awake animal models and provides neuroscientists with a standard approach for monitoring behavior and other associated physiological parameters in head-fixed animals.
Collapse
Affiliation(s)
- Qingguang Zhang
- The Pennsylvania State University, Center for Neural Engineering, Department of Engineering Science and Mechanics, University Park, Pennsylvania, United States
| | - Kevin L. Turner
- The Pennsylvania State University, Department of Biomedical Engineering, University Park, Pennsylvania, United States
| | - Kyle W. Gheres
- The Pennsylvania State University, Graduate Program in Molecular Cellular and Integrative Biosciences, University Park, Pennsylvania, United States
| | - Md Shakhawat Hossain
- The Pennsylvania State University, Department of Biomedical Engineering, University Park, Pennsylvania, United States
| | - Patrick J. Drew
- The Pennsylvania State University, Center for Neural Engineering, Department of Engineering Science and Mechanics, University Park, Pennsylvania, United States
- The Pennsylvania State University, Department of Biomedical Engineering, University Park, Pennsylvania, United States
- The Pennsylvania State University, Department of Neurosurgery, University Park, Pennsylvania, United States
| |
Collapse
|
4
|
Mayhew SD, Coleman SC, Mullinger KJ, Can C. Across the adult lifespan the ipsilateral sensorimotor cortex negative BOLD response exhibits decreases in magnitude and spatial extent suggesting declining inhibitory control. Neuroimage 2022; 253:119081. [PMID: 35278710 PMCID: PMC9130740 DOI: 10.1016/j.neuroimage.2022.119081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 03/07/2022] [Accepted: 03/07/2022] [Indexed: 11/27/2022] Open
Abstract
Ipsilateral sensorimotor (iSM1) cortex negative BOLD responses (NBR) are observed to unilateral tasks and are thought to reflect a functionally relevant component of sensorimotor inhibition. Evidence suggests that sensorimotor inhibitory mechanisms degrade with age, along with aspects of motor ability and dexterity. However, understanding of age-related changes to NBR is restricted by limited comparisons between young vs old adults groups with relatively small samples sizes. Here we analysed a BOLD fMRI dataset (obtained from the CamCAN repository) of 581 healthy subjects, gender-balanced, sampled from the whole adult lifespan performing a motor response task to an audio-visual stimulus. We aimed to investigate how sensorimotor and default-mode NBR characteristics of magnitude, spatial extent and response shape alter at every decade of the aging process. A linear decrease in iSM1 NBR magnitude was observed across the whole lifespan whereas the contralateral sensorimotor (cSM1) PBR magnitude was unchanged. An age-related decrease in the spatial extent of NBR and an increase in the ipsilateral positive BOLD response (PBR) was observed. This occurred alongside an increasing negative correlation between subject's iSM1 NBR and cSM1 PBR magnitude, reflecting a change in the balance between cortical excitation and inhibition. Conventional GLM analysis, using a canonical haemodynamic response (HR) function, showed disappearance of iSM1 NBR in subjects over 50 years of age. However, a deconvolution analysis showed that the shape of the iSM1 HR altered throughout the lifespan, with delayed time-to-peak and decreased magnitude. The most significant decreases in iSM1 HR magnitude occurred in older age (>60 years) but the first changes in shape and timing occurred as early as 30 years, suggesting possibility of separate mechanisms underlying these alterations. Reanalysis using data-driven HRs for each decade detected significant sensorimotor NBR into late older age, showing the importance of taking changes in HR morphology into account in fMRI aging studies. These results may reflect fMRI measures of the age-related decreases in transcollosal inhibition exerted upon ipsilateral sensorimotor cortex and alterations to the excitatory-inhibitory balance in the sensorimotor network.
Collapse
Affiliation(s)
- Stephen D Mayhew
- Centre for Human Brain Health (CHBH), School of Psychology, University of Birmingham, Birmingham, UK.
| | - Sebastian C Coleman
- Sir Peter Mansfield Imaging Centre (SPMIC), School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - Karen J Mullinger
- Centre for Human Brain Health (CHBH), School of Psychology, University of Birmingham, Birmingham, UK; Sir Peter Mansfield Imaging Centre (SPMIC), School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - Cam Can
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| |
Collapse
|
5
|
Zhang Q, Cramer SR, Ma Z, Turner KL, Gheres KW, Liu Y, Drew PJ, Zhang N. Brain-wide ongoing activity is responsible for significant cross-trial BOLD variability. Cereb Cortex 2022; 32:5311-5329. [PMID: 35179203 PMCID: PMC9712744 DOI: 10.1093/cercor/bhac016] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 01/09/2022] [Accepted: 01/11/2022] [Indexed: 12/27/2022] Open
Abstract
A notorious issue of task-based functional magnetic resonance imaging (fMRI) is its large cross-trial variability. To quantitatively characterize this variability, the blood oxygenation level-dependent (BOLD) signal can be modeled as a linear summation of a stimulation-relevant and an ongoing (i.e. stimulation-irrelevant) component. However, systematic investigation on the spatiotemporal features of the ongoing BOLD component and how these features affect the BOLD response is still lacking. Here we measured fMRI responses to light onsets and light offsets in awake rats. The neuronal response was simultaneously recorded with calcium-based fiber photometry. We established that between-region BOLD signals were highly correlated brain-wide at zero time lag, including regions that did not respond to visual stimulation, suggesting that the ongoing activity co-fluctuates across the brain. Removing this ongoing activity reduced cross-trial variability of the BOLD response by ~30% and increased its coherence with the Ca2+ signal. Additionally, the negative ongoing BOLD activity sometimes dominated over the stimulation-driven response and contributed to the post-stimulation BOLD undershoot. These results suggest that brain-wide ongoing activity is responsible for significant cross-trial BOLD variability, and this component can be reliably quantified and removed to improve the reliability of fMRI response. Importantly, this method can be generalized to virtually all fMRI experiments without changing stimulation paradigms.
Collapse
Affiliation(s)
- Qingqing Zhang
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, United States,Center for Neural Engineering, The Pennsylvania State University, University Park, PA 16802, United States
| | - Samuel R Cramer
- Center for Neural Engineering, The Pennsylvania State University, University Park, PA 16802, United States,The Neuroscience Graduate Program, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, United States
| | - Zilu Ma
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, United States,Center for Neural Engineering, The Pennsylvania State University, University Park, PA 16802, United States
| | - Kevin L Turner
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, United States,Center for Neural Engineering, The Pennsylvania State University, University Park, PA 16802, United States
| | - Kyle W Gheres
- Center for Neural Engineering, The Pennsylvania State University, University Park, PA 16802, United States,Graduate Program in Molecular, Cellular, and Integrative Biosciences, The Pennsylvania State University, University Park, PA 16802, United States
| | - Yikang Liu
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, United States,Center for Neural Engineering, The Pennsylvania State University, University Park, PA 16802, United States
| | - Patrick J Drew
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, United States,Center for Neural Engineering, The Pennsylvania State University, University Park, PA 16802, United States,The Neuroscience Graduate Program, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, United States,Graduate Program in Molecular, Cellular, and Integrative Biosciences, The Pennsylvania State University, University Park, PA 16802, United States,Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA 16802, United States,Department of Neurosurgery, The Pennsylvania State University, Hershey, PA 17033, United States
| | - Nanyin Zhang
- Corresponding author: Biomedical Engineering and Electrical Engineering, Lloyd & Dorothy Foehr Huck Chair in Brain Imaging, The Huck Institutes of Life Sciences, The Pennsylvania State University, W-341 Millennium Science Complex, University Park, PA 16802, United States.
| |
Collapse
|
6
|
Lim HK, You N, Bae S, Kang BM, Shon YM, Kim SG, Suh M. Differential contribution of excitatory and inhibitory neurons in shaping neurovascular coupling in different epileptic neural states. J Cereb Blood Flow Metab 2021; 41:1145-1161. [PMID: 32669018 PMCID: PMC8054729 DOI: 10.1177/0271678x20934071] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Understanding the neurovascular coupling (NVC) underlying hemodynamic changes in epilepsy is crucial to properly interpreting functional brain imaging signals associated with epileptic events. However, how excitatory and inhibitory neurons affect vascular responses in different epileptic states remains unknown. We conducted real-time in vivo measurements of cerebral blood flow (CBF), vessel diameter, and excitatory and inhibitory neuronal calcium signals during recurrent focal seizures. During preictal states, decreases in CBF and arteriole diameter were closely related to decreased γ-band local field potential (LFP) power, which was linked to relatively elevated excitatory and reduced inhibitory neuronal activity levels. Notably, this preictal condition was followed by a strengthened ictal event. In particular, the preictal inhibitory activity level was positively correlated with coherent oscillating activity specific to inhibitory neurons. In contrast, ictal states were characterized by elevated synchrony in excitatory neurons. Given these findings, we suggest that excitatory and inhibitory neurons differentially contribute to shaping the ictal and preictal neural states, respectively. Moreover, the preictal vascular activity, alongside with the γ-band, may reflect the relative levels of excitatory and inhibitory neuronal activity, and upcoming ictal activity. Our findings provide useful insights into how perfusion signals of different epileptic states are related in terms of NVC.
Collapse
Affiliation(s)
- Hyun-Kyoung Lim
- Center for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS), Suwon, South Korea.,Department of Biological Sciences, Sungkyunkwan University, Suwon, South Korea
| | - Nayeon You
- Center for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS), Suwon, South Korea.,Department of Biomedical Engineering, Sungkyunkwan University, Suwon, South Korea
| | - Sungjun Bae
- Center for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS), Suwon, South Korea.,Department of Biomedical Engineering, Sungkyunkwan University, Suwon, South Korea
| | - Bok-Man Kang
- Center for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS), Suwon, South Korea.,Department of Biomedical Engineering, Sungkyunkwan University, Suwon, South Korea
| | - Young-Min Shon
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - Seong-Gi Kim
- Center for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS), Suwon, South Korea.,Department of Biomedical Engineering, Sungkyunkwan University, Suwon, South Korea
| | - Minah Suh
- Center for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS), Suwon, South Korea.,Department of Biomedical Engineering, Sungkyunkwan University, Suwon, South Korea.,Biomedical Institute for Convergence at SKKU (BICS), Sungkyunkwan University, Suwon, South Korea.,Samsung Advanced Institute for Health Sciences & Technology (SAIHST), Sungkyunkwan University, Suwon, South Korea
| |
Collapse
|
7
|
Howarth C, Mishra A, Hall CN. More than just summed neuronal activity: how multiple cell types shape the BOLD response. Philos Trans R Soc Lond B Biol Sci 2021; 376:20190630. [PMID: 33190598 PMCID: PMC7116385 DOI: 10.1098/rstb.2019.0630] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/22/2020] [Indexed: 12/11/2022] Open
Abstract
Functional neuroimaging techniques are widely applied to investigations of human cognition and disease. The most commonly used among these is blood oxygen level-dependent (BOLD) functional magnetic resonance imaging. The BOLD signal occurs because neural activity induces an increase in local blood supply to support the increased metabolism that occurs during activity. This supply usually outmatches demand, resulting in an increase in oxygenated blood in an active brain region, and a corresponding decrease in deoxygenated blood, which generates the BOLD signal. Hence, the BOLD response is shaped by an integration of local oxygen use, through metabolism, and supply, in the blood. To understand what information is carried in BOLD signals, we must understand how several cell types in the brain-local excitatory neurons, inhibitory neurons, astrocytes and vascular cells (pericytes, vascular smooth muscle and endothelial cells), and their modulation by ascending projection neurons-contribute to both metabolism and haemodynamic changes. Here, we review the contributions of each cell type to the regulation of cerebral blood flow and metabolism, and discuss situations where a simplified interpretation of the BOLD response as reporting local excitatory activity may misrepresent important biological phenomena, for example with regards to arousal states, ageing and neurological disease. This article is part of the theme issue 'Key relationships between non-invasive functional neuroimaging and the underlying neuronal activity'.
Collapse
Affiliation(s)
- Clare Howarth
- Department of Psychology, University of Sheffield, Sheffield S1 2LT, UK
| | - Anusha Mishra
- Department of Neurology, Jungers Center for Neurosciences Research, and Knight Cardiovascular Institute, Oregon Health and Science University, Portland, OR 97239, USA
| | | |
Collapse
|
8
|
Gil R, Fernandes FF, Shemesh N. Neuroplasticity-driven timing modulations revealed by ultrafast functional magnetic resonance imaging. Neuroimage 2020; 225:117446. [PMID: 33069861 DOI: 10.1016/j.neuroimage.2020.117446] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 09/14/2020] [Accepted: 10/07/2020] [Indexed: 12/13/2022] Open
Abstract
Detecting neuroplasticity in global brain circuits in vivo is key for understanding myriad processes such as memory, learning, and recovery from injury. Functional Magnetic Resonance Imaging (fMRI) is instrumental for such in vivo mappings, yet it typically relies on mapping changes in spatial extent of activation or via signal amplitude modulations, whose interpretation can be highly ambiguous. Importantly, a central aspect of neuroplasticity involves modulation of neural activity timing properties. We thus hypothesized that this temporal dimension could serve as a new marker for neuroplasticity. To detect fMRI signals more associated with the underlying neural dynamics, we developed an ultrafast fMRI (ufMRI) approach facilitating high spatiotemporal sensitivity and resolution in distributed neural pathways. When neuroplasticity was induced in the mouse visual pathway via dark rearing, ufMRI indeed mapped temporal modulations in the entire visual pathway. Our findings therefore suggest a new dimension for exploring neuroplasticity in vivo.
Collapse
Affiliation(s)
- Rita Gil
- Champalimaud Research, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | | | - Noam Shemesh
- Champalimaud Research, Champalimaud Centre for the Unknown, Lisbon, Portugal.
| |
Collapse
|
9
|
Wilson R, Thomas A, Mayhew SD. Spatially congruent negative BOLD responses to different stimuli do not summate in visual cortex. Neuroimage 2020; 218:116891. [DOI: 10.1016/j.neuroimage.2020.116891] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 04/23/2020] [Accepted: 04/28/2020] [Indexed: 01/07/2023] Open
|
10
|
Lee L, Boorman L, Glendenning E, Christmas C, Sharp P, Redgrave P, Shabir O, Bracci E, Berwick J, Howarth C. Key Aspects of Neurovascular Control Mediated by Specific Populations of Inhibitory Cortical Interneurons. Cereb Cortex 2020; 30:2452-2464. [PMID: 31746324 PMCID: PMC7174996 DOI: 10.1093/cercor/bhz251] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 08/20/2019] [Accepted: 10/01/2019] [Indexed: 01/21/2023] Open
Abstract
Inhibitory interneurons can evoke vasodilation and vasoconstriction, making them potential cellular drivers of neurovascular coupling. However, the specific regulatory roles played by particular interneuron subpopulations remain unclear. Our purpose was therefore to adopt a cell-specific optogenetic approach to investigate how somatostatin (SST) and neuronal nitric oxide synthase (nNOS)-expressing interneurons might influence the neurovascular relationship. In mice, specific activation of SST- or nNOS-interneurons was sufficient to evoke hemodynamic changes. In the case of nNOS-interneurons, robust hemodynamic changes occurred with minimal changes in neural activity, suggesting that the ability of blood oxygen level dependent functional magnetic resonance imaging (BOLD fMRI) to reliably reflect changes in neuronal activity may be dependent on type of neuron recruited. Conversely, activation of SST-interneurons produced robust changes in evoked neural activity with shallow cortical excitation and pronounced deep layer cortical inhibition. Prolonged activation of SST-interneurons often resulted in an increase in blood volume in the centrally activated area with an accompanying decrease in blood volume in the surrounding brain regions, analogous to the negative BOLD signal. These results demonstrate the role of specific populations of cortical interneurons in the active control of neurovascular function.
Collapse
Affiliation(s)
- L Lee
- Department of Psychology, University of Sheffield, Sheffield S1 2LT, UK
| | - L Boorman
- Department of Psychology, University of Sheffield, Sheffield S1 2LT, UK
| | - E Glendenning
- Department of Psychology, University of Sheffield, Sheffield S1 2LT, UK
| | - C Christmas
- Department of Psychology, University of Sheffield, Sheffield S1 2LT, UK
| | - P Sharp
- Department of Psychology, University of Sheffield, Sheffield S1 2LT, UK
| | - P Redgrave
- Department of Psychology, University of Sheffield, Sheffield S1 2LT, UK
| | - O Shabir
- Department of Psychology, University of Sheffield, Sheffield S1 2LT, UK
| | - E Bracci
- Department of Psychology, University of Sheffield, Sheffield S1 2LT, UK
| | - J Berwick
- Department of Psychology, University of Sheffield, Sheffield S1 2LT, UK
| | - C Howarth
- Department of Psychology, University of Sheffield, Sheffield S1 2LT, UK
| |
Collapse
|
11
|
Vazquez AL, Fukuda M, Kim SG. Inhibitory Neuron Activity Contributions to Hemodynamic Responses and Metabolic Load Examined Using an Inhibitory Optogenetic Mouse Model. Cereb Cortex 2019; 28:4105-4119. [PMID: 30215693 PMCID: PMC6188559 DOI: 10.1093/cercor/bhy225] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 08/18/2018] [Indexed: 12/19/2022] Open
Abstract
Hemodynamic signals are routinely used to noninvasively assess brain function in humans and animals. This work examined the contribution of inhibitory neuron activity on hemodynamic responses captured by changes in blood flow, volume and oxygenation in the cortex of lightly anesthetized mice. Because cortical activity is not commonly initiated by inhibitory neurons, experiments were conducted to examine the neuronal activity properties elicited by photo-stimulation. We observed comparable increases in neuronal activity evoked by forelimb and photo-stimulation; however, significantly larger increases in blood flow and volume were produced by photo-stimulation of inhibitory neurons compared with forelimb stimulation. Following blockade of glutamate and GABA-A receptors to reduce postsynaptic activity contributions, neuronal activity was reliably modulated and hemodynamic changes persisted, though slightly reduced. More importantly, photo-stimulation-evoked changes in blood flow and volume were suppressed by 75–80% with the administration of a nitric oxide synthase inhibitor, suggesting that inhibitory neurons regulate blood flow mostly via nitric oxide. Lastly, forelimb and photo-stimulation of excitatory neurons produced local decreases in blood oxygenation, while large increases were generated by photo-stimulation of inhibitory neurons. Estimates of oxygen metabolism suggest that inhibitory neuron activity has a small impact on tissue metabolic load, indicating a mismatch between the metabolic demand and blood flow regulation properties of inhibitory and excitatory neurons.
Collapse
Affiliation(s)
- Alberto L Vazquez
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA.,Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
| | - Mitsuhiro Fukuda
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Seong-Gi Kim
- Department of Biomedical Engineering, Sungkyunkwan University, Suwon, Korea.,Center for Neuroscience Imaging Research, Institute for Basic Science, Sungkyunkwan University, Suwon, Korea
| |
Collapse
|
12
|
Neurovascular Coupling under Chronic Stress Is Modified by Altered GABAergic Interneuron Activity. J Neurosci 2019; 39:10081-10095. [PMID: 31672788 PMCID: PMC6978951 DOI: 10.1523/jneurosci.1357-19.2019] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 10/10/2019] [Accepted: 10/15/2019] [Indexed: 12/15/2022] Open
Abstract
Neurovascular coupling (NVC), the interaction between neural activity and vascular response, ensures normal brain function by maintaining brain homeostasis. We previously reported altered cerebrovascular responses during functional hyperemia in chronically stressed animals. However, the underlying neuronal-level changes associated with those hemodynamic changes remained unclear. Here, using in vivo and ex vivo experiments, we investigate the neuronal origins of altered NVC dynamics under chronic stress conditions in adult male mice. Stimulus-evoked hemodynamic and neural responses, especially beta and gamma-band local field potential activity, were significantly lower in chronically stressed animals, and the NVC relationship, itself, had changed. Further, using acute brain slices, we discovered that the underlying cause of this change was dysfunction of neuronal nitric oxide synthase (nNOS)-mediated vascular responses. Using FISH to check the mRNA expression of several GABAergic subtypes, we confirmed that only nNOS mRNA was significantly decreased in chronically stressed mice. Ultimately, chronic stress impairs NVC by diminishing nNOS-mediated vasodilation responses to local neural activity. Overall, these findings provide useful information in understanding NVC dynamics in the healthy brain. More importantly, this study reveals that impaired nNOS-mediated NVC function may be a contributory factor in the progression of stress-related diseases. SIGNIFICANCE STATEMENT The correlation between neuronal activity and cerebral vascular dynamics is defined as neurovascular coupling (NVC), which plays an important role for meeting the metabolic demands of the brain. However, the impact of chronic stress, which is a contributory factor of many cerebrovascular diseases, on NVC is poorly understood. We therefore investigated the effects of chronic stress on impaired neurovascular response to sensory stimulation and their underlying mechanisms. Multimodal approaches, from in vivo hemodynamic imaging and electrophysiology to ex vivo vascular imaging with pharmacological treatment, patch-clamp recording, FISH, and immunohistochemistry revealed that chronic stress-induced dysfunction of nNOS-expressing interneurons contributes to NVC impairment. These findings will provide useful information to understand the role of nNOS interneurons in NVC in normal and pathological conditions.
Collapse
|
13
|
Tzovara A, Meyer SS, Bonaiuto JJ, Abivardi A, Dolan RJ, Barnes GR, Bach DR. High-precision magnetoencephalography for reconstructing amygdalar and hippocampal oscillations during prediction of safety and threat. Hum Brain Mapp 2019; 40:4114-4129. [PMID: 31257708 PMCID: PMC6772181 DOI: 10.1002/hbm.24689] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 04/09/2019] [Accepted: 05/27/2019] [Indexed: 02/02/2023] Open
Abstract
Learning to associate neutral with aversive events in rodents is thought to depend on hippocampal and amygdala oscillations. In humans, oscillations underlying aversive learning are not well characterised, largely due to the technical difficulty of recording from these two structures. Here, we used high‐precision magnetoencephalography (MEG) during human discriminant delay threat conditioning. We constructed generative anatomical models relating neural activity with recorded magnetic fields at the single‐participant level, including the neocortex with or without the possibility of sources originating in the hippocampal and amygdalar structures. Models including neural activity in amygdala and hippocampus explained MEG data during threat conditioning better than exclusively neocortical models. We found that in both amygdala and hippocampus, theta oscillations during anticipation of an aversive event had lower power compared to safety, both during retrieval and extinction of aversive memories. At the same time, theta synchronisation between hippocampus and amygdala increased over repeated retrieval of aversive predictions, but not during safety. Our results suggest that high‐precision MEG is sensitive to neural activity of the human amygdala and hippocampus during threat conditioning and shed light on the oscillation‐mediated mechanisms underpinning retrieval and extinction of fear memories in humans.
Collapse
Affiliation(s)
- Athina Tzovara
- Department of Psychiatry, Psychotherapy, and Psychosomatics, University of Zurich, Zurich, Switzerland.,Neuroscience Centre Zurich, University of Zurich, Zurich, Switzerland.,Wellcome Centre for Human Neuroimaging, Institute of Neurology, University College London, London, United Kingdom.,Helen Wills Neuroscience Institute, University of California, Berkeley, California
| | - Sofie S Meyer
- Wellcome Centre for Human Neuroimaging, Institute of Neurology, University College London, London, United Kingdom.,UCL Institute of Cognitive Neuroscience, University College London, London, United Kingdom
| | - James J Bonaiuto
- Wellcome Centre for Human Neuroimaging, Institute of Neurology, University College London, London, United Kingdom
| | - Aslan Abivardi
- Department of Psychiatry, Psychotherapy, and Psychosomatics, University of Zurich, Zurich, Switzerland.,Neuroscience Centre Zurich, University of Zurich, Zurich, Switzerland
| | - Raymond J Dolan
- Wellcome Centre for Human Neuroimaging, Institute of Neurology, University College London, London, United Kingdom.,Max Planck UCL Centre for Computational Psychiatry and Ageing Research, University College London, London, United Kingdom
| | - Gareth R Barnes
- Wellcome Centre for Human Neuroimaging, Institute of Neurology, University College London, London, United Kingdom
| | - Dominik R Bach
- Department of Psychiatry, Psychotherapy, and Psychosomatics, University of Zurich, Zurich, Switzerland.,Neuroscience Centre Zurich, University of Zurich, Zurich, Switzerland.,Wellcome Centre for Human Neuroimaging, Institute of Neurology, University College London, London, United Kingdom.,Max Planck UCL Centre for Computational Psychiatry and Ageing Research, University College London, London, United Kingdom
| |
Collapse
|
14
|
Drew PJ. Vascular and neural basis of the BOLD signal. Curr Opin Neurobiol 2019; 58:61-69. [PMID: 31336326 DOI: 10.1016/j.conb.2019.06.004] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 06/22/2019] [Indexed: 12/26/2022]
Abstract
Neural activity in the brain is usually coupled to increases in local cerebral blood flow, leading to the increase in oxygenation that generates the BOLD fMRI signal. Recent work has begun to elucidate the vascular and neural mechanisms underlying the BOLD signal. The dilatory response is distributed throughout the vascular network. Arteries actively dilate within a second following neural activity increases, while venous distensions are passive and have a time course that last tens of seconds. Vasodilation, and thus local blood flow, is controlled by the activity of both neurons and astrocytes via multiple different pathways. The relationship between sensory-driven neural activity and the vascular dynamics in sensory areas are well-captured with a linear convolution model. However, depending on the behavioral state or brain region, the coupling between neural activity and hemodynamic signals can be weak or even inverted.
Collapse
Affiliation(s)
- Patrick J Drew
- Departments of Engineering Science and Mechanics, Biomedical Engineering and Neurosurgery, Pennsylvania State University, University Park, PA 16802, United States.
| |
Collapse
|
15
|
Wilson R, Mullinger KJ, Francis ST, Mayhew SD. The relationship between negative BOLD responses and ERS and ERD of alpha/beta oscillations in visual and motor cortex. Neuroimage 2019; 199:635-650. [PMID: 31189075 DOI: 10.1016/j.neuroimage.2019.06.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 04/10/2019] [Accepted: 06/03/2019] [Indexed: 01/06/2023] Open
Abstract
Previous work has investigated the electrophysiological origins of the intra-modal (within the stimulated sensory cortex) negative BOLD fMRI response (NBR, decrease from baseline) but little attention has been paid to the origin of cross-modal NBRs, those in a different sensory cortex. In the current study we use simultaneous EEG-fMRI recordings to assess the neural correlates of both intra- and cross-modal responses to left-hemifield visual stimuli and right-hand motor tasks, and evaluate the balance of activation and deactivation between the visual and motor systems. Within- and between-subject covariations of EEG and fMRI responses to both tasks are assessed to determine how patterns of event-related desynchronization/synchronisation (ERD/ERS) of alpha/beta frequency oscillations relate to the NBR in the two sensory cortices. We show that both visual and motor tasks induce intra-modal NBR and cross-modal NBR (e.g. visual stimuli evoked NBRs in both visual and motor cortices). In the EEG data, bilateral intra-modal alpha/beta ERD were consistently observed to both tasks, whilst the cross-modal EEG response varied across subjects between alpha/beta ERD and ERS. Both the mean cross-modal EEG and fMRI response amplitudes showed a small increase in magnitude with increasing task intensity. In response to the visual stimuli, subjects displaying cross-modal ERS of motor beta power displayed a significantly larger magnitude of cross-modal NBR in motor cortex. However, in contrast to the motor stimuli, larger cross-modal ERD of visual alpha power was associated with larger cross-modal visual NBR. Single-trial correlation analysis provided further evidence of relationship between EEG signals and the NBR, motor cortex beta responses to motor tasks were significantly negatively correlated with cross-modal visual cortex NBR amplitude, and positively correlated with intra-modal motor cortex PBR. This study provides a new body of evidence that the coupling between BOLD and low-frequency (alpha/beta) sensory cortex EEG responses extends to cross-modal NBR.
Collapse
Affiliation(s)
- Ross Wilson
- Centre for Human Brain Health (CHBH), University of Birmingham, Birmingham, UK
| | - Karen J Mullinger
- Centre for Human Brain Health (CHBH), University of Birmingham, Birmingham, UK; SPMIC, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - Susan T Francis
- SPMIC, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - Stephen D Mayhew
- Centre for Human Brain Health (CHBH), University of Birmingham, Birmingham, UK.
| |
Collapse
|
16
|
Kang S, Hayashi Y, Bruyns-Haylett M, Baker DH, Boura M, Wang X, Karatzas KA, Serra I, Bithell A, Williams C, Field DT, Zheng Y. Supplemental Vitamin B-12 Enhances the Neural Response to Sensory Stimulation in the Barrel Cortex of Healthy Rats but Does Not Affect Spontaneous Neural Activity. J Nutr 2019; 149:730-737. [PMID: 31006816 DOI: 10.1093/jn/nxz011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 12/07/2018] [Accepted: 01/17/2019] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Although vitamin B-12 (B-12) is known to contribute to the structural and functional development of the brain, it is unclear if B-12 supplementation has any beneficial effect in healthy populations in terms of enhanced neurologic status of the brain or improved cognitive function. OBJECTIVES We investigated the effect of dietary supplementation of B-12 on the cortical neural activity of well-nourished young adult rats and tested the hypothesis that B-12 supplementation in healthy rats may reduce sensory-evoked neural activity due to enhanced inhibition. METHODS Female Lister Hooded rats weighing 190-265 g (2-4 mo old) were included in the study. The experimental group was fed with B-12 (cyanocobalamin)-enriched water at a concentration of 1 mg/L, and the control (CON) group with tap water for 3 wk. Animals were then anesthetized and cortical neural responses to whisker stimulation were recorded in vivo through the use of a multichannel microelectrode, from which local field potentials (LFPs) were extracted. RESULTS Somatosensory-evoked LFP was 25% larger in the B-12 group (4.13 ± 0.24 mV) than in the CON group (3.30 ± 0.21 mV) (P = 0.02). Spontaneous neural activity did not differ between groups; frequency spectra at each frequency bin of interest did not pass the cluster-forming threshold at the 5% significance level. CONCLUSIONS These findings do not provide evidence supporting the hypothesis of decreased neural activity due to B-12 supplementation. As the spontaneous neural activity was unaffected, the increase in somatosensory-evoked LFP may be due to enhanced afferent signal reaching the barrel cortex from the whisker pad, indicating that B-12-supplemented rats may have enhanced sensitivity to sensory stimulation compared with the CON group. We suggest that this enhancement might be the result of lowered sensory threshold, although the underlying mechanism has yet to be elucidated.
Collapse
Affiliation(s)
- Sungmin Kang
- Biomedical Engineering, School of Biological Sciences.,Centre for Integrative Neuroscience and Neurodynamics (CINN), University of Reading, Reading, United Kingdom
| | - Yurie Hayashi
- Biomedical Engineering, School of Biological Sciences
| | | | - Daniel H Baker
- Department of Psychology and York Biomedical Research Institute, University of York, York, United Kingdom
| | | | | | - Kimon-Andreas Karatzas
- Food and Nutritional Sciences.,Centre for Integrative Neuroscience and Neurodynamics (CINN), University of Reading, Reading, United Kingdom
| | - Ines Serra
- Pharmacy, School of Chemistry, Food and Pharmacy
| | | | - Claire Williams
- Psychology, School of Psychology and Clinical Language Sciences
| | - David T Field
- Centre for Integrative Neuroscience and Neurodynamics (CINN), University of Reading, Reading, United Kingdom
| | - Ying Zheng
- Biomedical Engineering, School of Biological Sciences.,Centre for Integrative Neuroscience and Neurodynamics (CINN), University of Reading, Reading, United Kingdom
| |
Collapse
|
17
|
Linking brain vascular physiology to hemodynamic response in ultra-high field MRI. Neuroimage 2018; 168:279-295. [DOI: 10.1016/j.neuroimage.2017.02.063] [Citation(s) in RCA: 101] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2016] [Revised: 02/20/2017] [Accepted: 02/21/2017] [Indexed: 01/05/2023] Open
|
18
|
Uji M, Wilson R, Francis ST, Mullinger KJ, Mayhew SD. Exploring the advantages of multiband fMRI with simultaneous EEG to investigate coupling between gamma frequency neural activity and the BOLD response in humans. Hum Brain Mapp 2018; 39:1673-1687. [PMID: 29331056 DOI: 10.1002/hbm.23943] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 12/17/2017] [Accepted: 12/21/2017] [Indexed: 01/18/2023] Open
Abstract
We established an optimal combination of EEG recording during sparse multiband (MB) fMRI that preserves high-resolution, whole-brain fMRI coverage while enabling broad-band EEG recordings which are uncorrupted by MRI gradient artefacts (GAs). We first determined the safety of simultaneous EEG recording during MB fMRI. Application of MB factor = 4 produced <1°C peak heating of electrode/hardware during 20 min of GE-EPI data acquisition. However, higher SAR sequences require specific safety testing, with greater heating observed using PCASL with MB factor = 4. Heating was greatest in the electrocardiogram channel, likely due to it possessing longest lead length. We investigated the effect of MB factor on the temporal signal-to-noise ratio for a range of GE-EPI sequences (varying MB factor and temporal interval between slice acquisitions). We found that, for our experimental purpose, the optimal acquisition was achieved with MB factor = 3, 3mm isotropic voxels, and 33 slices providing whole head coverage. This sequence afforded a 2.25 s duration quiet period (without GAs) in every 3 s TR. Using this sequence, we demonstrated the ability to record gamma frequency (55-80 Hz) EEG oscillations, in response to right index finger abduction, that are usually obscured by GAs during continuous fMRI data acquisition. In this novel application of EEG-MB fMRI to a motor task, we observed a positive correlation between gamma and BOLD responses in bilateral motor regions. These findings support and extend previous work regarding coupling between neural and hemodynamic measures of brain activity in humans and showcase the utility of EEG-MB fMRI for future investigations.
Collapse
Affiliation(s)
- Makoto Uji
- Centre for Human Brain Health (CHBH), School of Psychology, University of Birmingham, Birmingham, United Kingdom
| | - Ross Wilson
- Centre for Human Brain Health (CHBH), School of Psychology, University of Birmingham, Birmingham, United Kingdom
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre (SPMIC), School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom
| | - Karen J Mullinger
- Centre for Human Brain Health (CHBH), School of Psychology, University of Birmingham, Birmingham, United Kingdom.,Sir Peter Mansfield Imaging Centre (SPMIC), School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom
| | - Stephen D Mayhew
- Centre for Human Brain Health (CHBH), School of Psychology, University of Birmingham, Birmingham, United Kingdom
| |
Collapse
|
19
|
Harris SS, Boorman LW, Kennerley AJ, Sharp PS, Martin C, Redgrave P, Schwartz TH, Berwick J. Seizure epicenter depth and translaminar field potential synchrony underlie complex variations in tissue oxygenation during ictal initiation. Neuroimage 2017; 171:165-175. [PMID: 29294386 PMCID: PMC5883323 DOI: 10.1016/j.neuroimage.2017.12.088] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2017] [Revised: 12/01/2017] [Accepted: 12/27/2017] [Indexed: 12/21/2022] Open
Abstract
Whether functional hyperemia during epileptic activity is adequate to meet the heightened metabolic demand of such events is controversial. Whereas some studies have demonstrated hyperoxia during ictal onsets, other work has reported transient hypoxic episodes that are spatially dependent on local surface microvasculature. Crucially, how laminar differences in ictal evolution can affect subsequent cerebrovascular responses has not been thus far investigated, and is likely significant in view of possible laminar-dependent neurovascular mechanisms and angioarchitecture. We addressed this open question using a novel multi-modal methodology enabling concurrent measurement of cortical tissue oxygenation, blood flow and hemoglobin concentration, alongside laminar recordings of neural activity, in a urethane anesthetized rat model of recurrent seizures induced by 4-aminopyridine. We reveal there to be a close relationship between seizure epicenter depth, translaminar local field potential (LFP) synchrony and tissue oxygenation during the early stages of recurrent seizures, whereby deep layer seizures are associated with decreased cross laminar synchrony and prolonged periods of hypoxia, and middle layer seizures are accompanied by increased cross-laminar synchrony and hyperoxia. Through comparison with functional activation by somatosensory stimulation and graded hypercapnia, we show that these seizure-related cerebrovascular responses occur in the presence of conserved neural-hemodynamic and blood flow-volume coupling. Our data provide new insights into the laminar dependency of seizure-related neurovascular responses, which may reconcile inconsistent observations of seizure-related hypoxia in the literature, and highlight a potential layer-dependent vulnerability that may contribute to the harmful effects of clinical recurrent seizures. The relevance of our findings to perfusion-related functional neuroimaging techniques in epilepsy are also discussed.
Collapse
Affiliation(s)
- Samuel S Harris
- Department of Psychology, Neurovascular and Neuroimaging Research Group, University of Sheffield, Sheffield S10 2TN, UK.
| | - Luke W Boorman
- Department of Psychology, Neurovascular and Neuroimaging Research Group, University of Sheffield, Sheffield S10 2TN, UK
| | - Aneurin J Kennerley
- Department of Psychology, Neurovascular and Neuroimaging Research Group, University of Sheffield, Sheffield S10 2TN, UK
| | - Paul S Sharp
- Department of Psychology, Neurovascular and Neuroimaging Research Group, University of Sheffield, Sheffield S10 2TN, UK
| | - Chris Martin
- Department of Psychology, Neurovascular and Neuroimaging Research Group, University of Sheffield, Sheffield S10 2TN, UK
| | - Peter Redgrave
- Department of Psychology, Neurovascular and Neuroimaging Research Group, University of Sheffield, Sheffield S10 2TN, UK
| | - Theodore H Schwartz
- Department of Neurological Surgery, Brain and Mind Research Institute, Brain and Spine Center, Weill Cornell Medical College, New York Presbyterian Hospital, 525 East 68th Street, Box 99, New York, NY 10021, USA
| | - Jason Berwick
- Department of Psychology, Neurovascular and Neuroimaging Research Group, University of Sheffield, Sheffield S10 2TN, UK
| |
Collapse
|
20
|
Golkowski D, Ranft A, Kiel T, Riedl V, Kohl P, Rohrer G, Pientka J, Berger S, Preibisch C, Zimmer C, Mashour GA, Schneider G, Kochs EF, Ilg R, Jordan D. Coherence of BOLD signal and electrical activity in the human brain during deep sevoflurane anesthesia. Brain Behav 2017; 7:e00679. [PMID: 28729926 PMCID: PMC5516594 DOI: 10.1002/brb3.679] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Revised: 12/23/2016] [Accepted: 02/16/2017] [Indexed: 12/03/2022] Open
Abstract
INTRODUCTION Changes in neural activity induce changes in functional magnetic resonance (fMRI) blood oxygenation level dependent (BOLD) signal. Commonly, increases in BOLD signal are ascribed to cellular excitation. OBJECTIVE The relationship between electrical activity and BOLD signal in the human brain was probed on the basis of burst suppression EEG. This condition includes two distinct states of high and low electrical activity. METHODS Resting-state simultaneous EEG and BOLD measurements were acquired during deep sevoflurane anesthesia with burst suppression EEG in nineteen healthy volunteers. Afterwards, fMRI volumes were assigned to one of the two states (burst or suppression) as defined by the EEG. RESULTS In the frontal, parietal and temporal lobes as well as in the basal ganglia, BOLD signal increased after burst onset in the EEG and decreased after onset of EEG suppression. In contrast, BOLD signal in the occipital lobe was anticorrelated to electrical activity. This finding was obtained consistently in a general linear model and in raw data. CONCLUSIONS In human brains exhibiting burst suppression EEG induced by sevoflurane, the positive correlation between BOLD signal and electrical brain activity could be confirmed in most gray matter. The exceptional behavior of the occipital lobe with an anticorrelation of BOLD signal and electrical activity might be due to specific neurovascular coupling mechanisms that are pronounced in the deeply anesthetized brain.
Collapse
Affiliation(s)
- Daniel Golkowski
- Department of Neurology Klinikum rechts der Isar der Technischen Universität München München Germany
| | - Andreas Ranft
- Department of Anesthesiology Klinikum rechts der Isar der Technischen Universität München München Germany
| | - Tobias Kiel
- Department of Anesthesiology Klinikum rechts der Isar der Technischen Universität München München Germany
| | - Valentin Riedl
- Department of Neuroradiology Klinikum rechts der Isar der Technischen Universität München München Germany
| | - Philipp Kohl
- Department of Neurology Klinikum rechts der Isar der Technischen Universität München München Germany.,Department of Anesthesiology Klinikum rechts der Isar der Technischen Universität München München Germany
| | - Guido Rohrer
- Department of Neurology Klinikum rechts der Isar der Technischen Universität München München Germany.,Department of Anesthesiology Klinikum rechts der Isar der Technischen Universität München München Germany
| | - Joachim Pientka
- Department of Anesthesiology Klinikum rechts der Isar der Technischen Universität München München Germany
| | - Sebastian Berger
- Department of Anesthesiology Klinikum rechts der Isar der Technischen Universität München München Germany
| | - Christine Preibisch
- Department of Neuroradiology Klinikum rechts der Isar der Technischen Universität München München Germany
| | - Claus Zimmer
- Department of Neuroradiology Klinikum rechts der Isar der Technischen Universität München München Germany
| | - George A Mashour
- Department of Anesthesiology University of Michigan Medical School Ann Arbor MI USA
| | - Gerhard Schneider
- Department of Anesthesiology Klinikum rechts der Isar der Technischen Universität München München Germany
| | - Eberhard F Kochs
- Department of Anesthesiology Klinikum rechts der Isar der Technischen Universität München München Germany
| | - Rüdiger Ilg
- Department of Neurology Klinikum rechts der Isar der Technischen Universität München München Germany.,Department of Neurology Asklepios Kliniken Bad Tölz Germany
| | - Denis Jordan
- Department of Anesthesiology Klinikum rechts der Isar der Technischen Universität München München Germany
| |
Collapse
|
21
|
Abstract
Neural oscillations in hippocampus and medial prefrontal cortex (mPFC) are a hallmark of rodent anxiety models that build on conflict between approach and avoidance. Yet, the function of these oscillations, and their expression in humans, remain elusive. Here, we used magnetoencephalography (MEG) to investigate neural oscillations in a task that simulated approach–avoidance conflict, wherein 23 male and female human participants collected monetary tokens under a threat of virtual predation. Probability of threat was signaled by color and learned beforehand by direct experience. Magnitude of threat corresponded to a possible monetary loss, signaled as a quantity. We focused our analyses on an a priori defined region-of-interest, the bilateral hippocampus. Oscillatory power under conflict was linearly predicted by threat probability in a location consistent with right mid-hippocampus. This pattern was specific to the hippocampus, most pronounced in the gamma band, and not explained by spatial movement or anxiety-like behavior. Gamma power was modulated by slower theta rhythms, and this theta modulation increased with threat probability. Furthermore, theta oscillations in the same location showed greater synchrony with mPFC theta with increased threat probability. Strikingly, these findings were not seen in relation to an increase in threat magnitude, which was explicitly signaled as a quantity and induced similar behavioral responses as learned threat probability. Thus, our findings suggest that the expression of hippocampal and mPFC oscillatory activity in the context of anxiety is specifically linked to threat memory. These findings resonate with neurocomputational accounts of the role played by hippocampal oscillations in memory. SIGNIFICANCE STATEMENT We use a biologically relevant approach–avoidance conflict test in humans while recording neural oscillations with magnetoencephalography to investigate the expression and function of hippocampal oscillations in human anxiety. Extending nonhuman studies, we can assign a possible function to hippocampal oscillations in this task, namely threat memory communication. This blends into recent attempts to elucidate the role of brain synchronization in defensive responses to threat.
Collapse
|
22
|
Keilholz SD, Pan WJ, Billings J, Nezafati M, Shakil S. Noise and non-neuronal contributions to the BOLD signal: applications to and insights from animal studies. Neuroimage 2016; 154:267-281. [PMID: 28017922 DOI: 10.1016/j.neuroimage.2016.12.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 10/21/2016] [Accepted: 12/08/2016] [Indexed: 01/08/2023] Open
Abstract
The BOLD signal reflects hemodynamic events within the brain, which in turn are driven by metabolic changes and neural activity. However, the link between BOLD changes and neural activity is indirect and can be influenced by a number of non-neuronal processes. Motion and physiological cycles have long been known to affect the BOLD signal and are present in both humans and animal models. Differences in physiological baseline can also contribute to intra- and inter-subject variability. The use of anesthesia, common in animal studies, alters neural activity, vascular tone, and neurovascular coupling. Most intriguing, perhaps, are the contributions from other processes that do not appear to be neural in origin but which may provide information about other aspects of neurophysiology. This review discusses different types of noise and non-neuronal contributors to the BOLD signal, sources of variability for animal studies, and insights to be gained from animal models.
Collapse
Affiliation(s)
- Shella D Keilholz
- Wallace H. Coulter Department of Biomedical Engineering, Emory University/Georgia Institute of Technology, Atlanta, GA, United States; Neuroscience Program, Emory University, Atlanta, GA, United States.
| | - Wen-Ju Pan
- Wallace H. Coulter Department of Biomedical Engineering, Emory University/Georgia Institute of Technology, Atlanta, GA, United States
| | - Jacob Billings
- Neuroscience Program, Emory University, Atlanta, GA, United States
| | - Maysam Nezafati
- Wallace H. Coulter Department of Biomedical Engineering, Emory University/Georgia Institute of Technology, Atlanta, GA, United States
| | - Sadia Shakil
- Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, United States
| |
Collapse
|
23
|
Resting-state hemodynamics are spatiotemporally coupled to synchronized and symmetric neural activity in excitatory neurons. Proc Natl Acad Sci U S A 2016; 113:E8463-E8471. [PMID: 27974609 DOI: 10.1073/pnas.1525369113] [Citation(s) in RCA: 194] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Brain hemodynamics serve as a proxy for neural activity in a range of noninvasive neuroimaging techniques including functional magnetic resonance imaging (fMRI). In resting-state fMRI, hemodynamic fluctuations have been found to exhibit patterns of bilateral synchrony, with correlated regions inferred to have functional connectivity. However, the relationship between resting-state hemodynamics and underlying neural activity has not been well established, making the neural underpinnings of functional connectivity networks unclear. In this study, neural activity and hemodynamics were recorded simultaneously over the bilateral cortex of awake and anesthetized Thy1-GCaMP mice using wide-field optical mapping. Neural activity was visualized via selective expression of the calcium-sensitive fluorophore GCaMP in layer 2/3 and 5 excitatory neurons. Characteristic patterns of resting-state hemodynamics were accompanied by more rapidly changing bilateral patterns of resting-state neural activity. Spatiotemporal hemodynamics could be modeled by convolving this neural activity with hemodynamic response functions derived through both deconvolution and gamma-variate fitting. Simultaneous imaging and electrophysiology confirmed that Thy1-GCaMP signals are well-predicted by multiunit activity. Neurovascular coupling between resting-state neural activity and hemodynamics was robust and fast in awake animals, whereas coupling in urethane-anesthetized animals was slower, and in some cases included lower-frequency (<0.04 Hz) hemodynamic fluctuations that were not well-predicted by local Thy1-GCaMP recordings. These results support that resting-state hemodynamics in the awake and anesthetized brain are coupled to underlying patterns of excitatory neural activity. The patterns of bilaterally-symmetric spontaneous neural activity revealed by wide-field Thy1-GCaMP imaging may depict the neural foundation of functional connectivity networks detected in resting-state fMRI.
Collapse
|
24
|
Bruyns-Haylett M, Luo J, Kennerley AJ, Harris S, Boorman L, Milne E, Vautrelle N, Hayashi Y, Whalley BJ, Jones M, Berwick J, Riera J, Zheng Y. The neurogenesis of P1 and N1: A concurrent EEG/LFP study. Neuroimage 2016; 146:575-588. [PMID: 27646129 PMCID: PMC5312787 DOI: 10.1016/j.neuroimage.2016.09.034] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 08/19/2016] [Accepted: 09/15/2016] [Indexed: 10/29/2022] Open
Abstract
It is generally recognised that event related potentials (ERPs) of electroencephalogram (EEG) primarily reflect summed post-synaptic activity of the local pyramidal neural population(s). However, it is still not understood how the positive and negative deflections (e.g. P1, N1 etc) observed in ERP recordings are related to the underlying excitatory and inhibitory post-synaptic activity. We investigated the neurogenesis of P1 and N1 in ERPs by pharmacologically manipulating inhibitory post-synaptic activity in the somatosensory cortex of rodent, and concurrently recording EEG and local field potentials (LFPs). We found that the P1 wave in the ERP and LFP of the supragranular layers is determined solely by the excitatory post-synaptic activity of the local pyramidal neural population, as is the initial segment of the N1 wave across cortical depth. The later part of the N1 wave was modulated by inhibitory post-synaptic activity, with its peak and the pulse width increasing as inhibition was reduced. These findings suggest that the temporal delay of inhibition with respect to excitation observed in intracellular recordings is also reflected in extracellular field potentials (FPs), resulting in a temporal window during which only excitatory post-synaptic activity and leak channel activity are recorded in the ERP and evoked LFP time series. Based on these findings, we provide clarification on the interpretation of P1 and N1 in terms of the excitatory and inhibitory post-synaptic activities of the local pyramidal neural population(s).
Collapse
Affiliation(s)
- Michael Bruyns-Haylett
- School of Systems Engineering, Whiteknights, University of Reading, Reading RG6 7AY, United Kingdom.
| | - Jingjing Luo
- School of Systems Engineering, Whiteknights, University of Reading, Reading RG6 7AY, United Kingdom.
| | - Aneurin J Kennerley
- Department of Psychology, University of Sheffield, Sheffield S10 2TP, United Kingdom
| | - Sam Harris
- Department of Psychology, University of Sheffield, Sheffield S10 2TP, United Kingdom
| | - Luke Boorman
- Department of Psychology, University of Sheffield, Sheffield S10 2TP, United Kingdom
| | - Elizabeth Milne
- Department of Psychology, University of Sheffield, Sheffield S10 2TP, United Kingdom
| | - Nicolas Vautrelle
- Department of Psychology, University of Sheffield, Sheffield S10 2TP, United Kingdom
| | - Yurie Hayashi
- School of Systems Engineering, Whiteknights, University of Reading, Reading RG6 7AY, United Kingdom
| | - Benjamin J Whalley
- School of Systems Engineering, Whiteknights, University of Reading, Reading RG6 7AY, United Kingdom
| | - Myles Jones
- Department of Psychology, University of Sheffield, Sheffield S10 2TP, United Kingdom
| | - Jason Berwick
- Department of Psychology, University of Sheffield, Sheffield S10 2TP, United Kingdom
| | - Jorge Riera
- Department of Biomedical Engineering, Florida International University, Miami, FL 33174, United States of America
| | - Ying Zheng
- School of Systems Engineering, Whiteknights, University of Reading, Reading RG6 7AY, United Kingdom.
| |
Collapse
|
25
|
Slack R, Boorman L, Patel P, Harris S, Bruyns-Haylett M, Kennerley A, Jones M, Berwick J. A novel method for classifying cortical state to identify the accompanying changes in cerebral hemodynamics. J Neurosci Methods 2016; 267:21-34. [PMID: 27063501 PMCID: PMC4896992 DOI: 10.1016/j.jneumeth.2016.04.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2015] [Revised: 03/29/2016] [Accepted: 04/06/2016] [Indexed: 11/27/2022]
Abstract
We classified brain state using a vector-based categorisation of neural frequencies. Changes in cerebral blood volume (CBV) were observed when brain state altered. During these state alterations, changes in blood oxygenation were also found. State dependent haemodynamic changes could affect blood based brain imaging.
Background Many brain imaging techniques interpret the haemodynamic response as an indirect indicator of underlying neural activity. However, a challenge when interpreting this blood based signal is how changes in brain state may affect both baseline and stimulus evoked haemodynamics. New method We developed an Automatic Brain State Classifier (ABSC), validated on data from anaesthetised rodents. It uses vectorised information obtained from the windowed spectral frequency power of the Local Field Potential. Current state is then classified by comparing this vectorised information against that calculated from state specific training datasets. Results The ABSC identified two user defined brain states (synchronised and desynchronised), with high accuracy (∼90%). Baseline haemodynamics were found to be significantly different in the two identified states. During state defined periods of elevated baseline haemodynamics we found significant decreases in evoked haemodynamic responses to somatosensory stimuli. Comparison to existing methods State classification – The ABSC (∼90%) demonstrated greater accuracy than clustering (∼66%) or ‘power threshold’ (∼64%) methods of comparison. Haemodynamic averaging – Our novel approach of selectively averaging stimulus evoked haemodynamic trials by brain state yields higher quality data than creating a single average from all trials. Conclusions The ABSC can account for some of the commonly observed trial-to-trial variability in haemodynamic responses which arises from changes in cortical state. This variability might otherwise be incorrectly attributed to alternative interpretations. A greater understanding of the effects of cortical state on haemodynamic changes could be used to inform techniques such as general linear modelling (GLM), commonly used in fMRI.
Collapse
Affiliation(s)
- R Slack
- Department of Psychology, University of Sheffield, Western Bank, Sheffield S10 2TN, United Kingdom.
| | - L Boorman
- Department of Psychology, University of Sheffield, Western Bank, Sheffield S10 2TN, United Kingdom.
| | - P Patel
- Department of Psychology, University of Sheffield, Western Bank, Sheffield S10 2TN, United Kingdom.
| | - S Harris
- Department of Psychology, University of Sheffield, Western Bank, Sheffield S10 2TN, United Kingdom.
| | - M Bruyns-Haylett
- Department of Systems Engineering, University of Reading, Whiteknights, Reading RG6 6AY, United Kingdom.
| | - A Kennerley
- Department of Psychology, University of Sheffield, Western Bank, Sheffield S10 2TN, United Kingdom.
| | - M Jones
- Department of Psychology, University of Sheffield, Western Bank, Sheffield S10 2TN, United Kingdom.
| | - J Berwick
- Department of Psychology, University of Sheffield, Western Bank, Sheffield S10 2TN, United Kingdom.
| |
Collapse
|
26
|
Ma Z, Cao P, Sun P, Zhao L, Li L, Tong S, Lu Y, Yan Y, Chen Y, Chai X. Inverted optical intrinsic response accompanied by decreased cerebral blood flow are related to both neuronal inhibition and excitation. Sci Rep 2016; 6:21627. [PMID: 26860040 PMCID: PMC4748280 DOI: 10.1038/srep21627] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 01/27/2016] [Indexed: 01/27/2023] Open
Abstract
Negative hemodynamic response has been widely reported in blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging studies, however its origin is still controversial. Optical intrinsic signal (OIS) imaging can be used to study brain activity by simultaneously recording hemodynamic signals at different wavelengths with high spatial resolution. In this study, we found transcorneal electrical stimulation (TcES) could elicit both positive OIS response (POR) and negative OIS response (NOR) in cats’ visual cortex. We then investigated the property of this negative response to TcES and its relationship with cerebral blood flow (CBF) and neuronal activity. Results from laser speckle contrast imaging showed decreased CBF in the NOR region while increased CBF in the POR region. Both planar and laminar electrophysiological recordings in the middle (500–700 μm) cortical layers demonstrated that decreased and increased neuronal activities were coexisted in the NOR region. Furthermore, decreased neuronal activity was also detected in the deep cortical layers in the NOR region. This work provides evidence that the negative OIS together with the decreased CBF should be explained by mechanisms of both neuronal inhibition and excitation within middle cortical layers. Our results would be important for interpreting neurophysiological mechanisms underlying the negative BOLD signals.
Collapse
Affiliation(s)
- Zengguang Ma
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Pengjia Cao
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Pengcheng Sun
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Linna Zhao
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Liming Li
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Shanbao Tong
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yiliang Lu
- Institute of Neuroscience and State Key Laboratory of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Yan Yan
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yao Chen
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xinyu Chai
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| |
Collapse
|