Functional Activities Detected in the Olfactory Bulb and Associated Olfactory Regions in the Human Brain Using T2-Prepared BOLD Functional MRI at 7T

Olfaction is a fundamental sense that plays a vital role in daily life in humans, and can be altered in neuropsychiatric and neurodegenerative diseases. Blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI) using conventional echo-planar-imaging (EPI) based sequences can be challenging in brain regions important for olfactory processing, such as the olfactory bulb (OB) and orbitofrontal cortex, mainly due to the signal dropout and distortion artifacts caused by large susceptibility effects from the sinonasal cavity and temporal bone. To date, few studies have demonstrated successful fMRI in the OB in humans. T2-prepared (T2prep) BOLD fMRI is an alternative approach developed especially for performing fMRI in regions affected by large susceptibility artifacts. The purpose of this technical study is to evaluate T2prep BOLD fMRI for olfactory functional experiments in humans. Olfactory fMRI scans were performed on 7T in 14 healthy participants. T2prep BOLD showed greater sensitivity than GRE EPI BOLD in the OB, orbitofrontal cortex and the temporal pole. Functional activation was detected using T2prep BOLD in the OB and associated olfactory regions. Habituation effects and a bi-phasic pattern of fMRI signal changes during olfactory stimulation were observed in all regions. Both positively and negatively activated regions were observed during olfactory stimulation. These signal characteristics are generally consistent with literature and showed a good intra-subject reproducibility comparable to previous human BOLD fMRI studies. In conclusion, the methodology demonstrated in this study holds promise for future olfactory fMRI studies in the OB and other brain regions that suffer from large susceptibility artifacts.

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Effect of Luminance Contrast on BOLD fMRI Response in Human Primary Visual Areas

Journal of Neurophysiology ◽

10.1152/jn.1998.79.4.2204 ◽

1998 ◽

Vol 79 (4) ◽

pp. 2204-2207 ◽

Cited By ~ 55

Author(s):

Bradley G. Goodyear ◽

Ravi S. Menon

Keyword(s):

Luminance Contrast ◽

Blood Oxygenation ◽

Planar Imaging ◽

Bold Fmri ◽

Activation Level ◽

Red Led ◽

Visual Areas ◽

Oxygenation Level ◽

Fmri Response ◽

Image Pixels

Goodyear, Bradley G. and Ravi S. Menon. Effect of luminance contrast on BOLD fMRI response in human primary visual areas. J. Neurophysiol. 79: 2204–2207, 1998. In this study, we examined the effect of stimulus luminance contrast on blood-oxygenation-level-dependent (BOLD) functional magnetic resonance imaging within human visual cortex (V1 and extrastriate). Between experiments, the calibrated luminance of a single red LED covering 2° of the subject's visual field was changed relative to a constant background luminance. This stimulus provided a different foveal luminance contrast for each experiment. We used an echo planar imaging sequence to collect blood-oxygenation-sensitive images during and in the absence of the presented stimulus. Our results showed that within V1 there was an increase in the spatial extent of activation with increasing stimulus contrast, but no trend was seen within extrastriate. In both V1 and extrastriate, the local mean activation level for all activated image pixels remained constant with increasing luminance contrast. However, when we investigated activated pixels common to all luminance contrast levels, we found that there was an increase in the mean activation level within V1, but not within extrastriate. These results suggest that there is an increase in the activity of cells in V1 with increasing luminance contrast.

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Finding the neural correlates of collaboration using a three-person fMRI hyperscanning paradigm

10.1101/782870 ◽

2019 ◽

Author(s):

Hua Xie ◽

Amber Howell ◽

Meredith Schreier ◽

Kristen E. Sheau ◽

Mai K. Manchanda ◽

...

Keyword(s):

Neural Correlates ◽

Brain Regions ◽

Vital Role ◽

Blood Oxygenation ◽

Evolutionary Significance ◽

Drawing Task ◽

The Social ◽

Oxygenation Level ◽

The Right ◽

First Time

AbstractHumans have an extraordinary ability to interact and cooperate with others, which plays a pivotal role in societies at large. Despite its potential social and evolutionary significance, research on finding the neural correlates of collaboration has been limited partly due to restrictions on simultaneous neuroimaging of more than one participant (a.k.a. hyperscanning). A series of works now exists that used dyadic fMRI hyperscanning to examine the interaction between two participants. However, to our knowledge, no study to date has aimed at revealing the neural correlates of social interactions using a 3-person (or triadic) fMRI hyperscanning paradigm. Here, for the first time, we simultaneously measured the blood-oxygenation-level-dependent (BOLD) signal of triads (m=12 triads; n=36 participants), while they engaged in a joint drawing task based on the social game of Pictionary®. General linear model (GLM) analysis revealed increased activation in the brain regions previously linked with the theory of mind (ToM) during the collaborative phase compared to the independent phase of the task. Furthermore, using intersubject brain synchronization (IBS) analysis, we revealed increased synchrony of the right temporo-parietal junction (R TPJ) during the collaborative phase. The increased synchrony in the R TPJ was observed to be positively associated with the overall team performance on the task. In sum, our novel paradigm revealed a vital role of the R TPJ among other ToM regions during a triadic collaborative drawing task.

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Finding the neural correlates of collaboration using a three-person fMRI hyperscanning paradigm

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1917407117 ◽

2020 ◽

Vol 117 (37) ◽

pp. 23066-23072 ◽

Cited By ~ 1

Author(s):

Hua Xie ◽

Iliana I. Karipidis ◽

Amber Howell ◽

Meredith Schreier ◽

Kristen E. Sheau ◽

...

Keyword(s):

Theory Of Mind ◽

Neural Correlates ◽

Brain Regions ◽

Vital Role ◽

Blood Oxygenation ◽

Evolutionary Significance ◽

General Linear Model Analysis ◽

Drawing Task ◽

The Social ◽

The Right

Humans have an extraordinary ability to interact and cooperate with others. Despite the social and evolutionary significance of collaboration, research on finding its neural correlates has been limited partly due to restrictions on the simultaneous neuroimaging of more than one participant (also known as hyperscanning). Several studies have used dyadic fMRI hyperscanning to examine the interaction between two participants. However, to our knowledge, no study to date has aimed at revealing the neural correlates of social interactions using a three-person (or triadic) fMRI hyperscanning paradigm. Here, we simultaneously measured the blood-oxygenation level-dependent signal from 12 triads (n = 36 participants), while they engaged in a collaborative drawing task based on the social game of Pictionary. General linear model analysis revealed increased activation in the brain regions previously linked with the theory of mind during the collaborative phase compared to the independent phase of the task. Furthermore, using intersubject correlation analysis, we revealed increased synchronization of the right temporo‐parietal junction (R TPJ) during the collaborative phase. The increased synchrony in the R TPJ was observed to be positively associated with the overall team performance on the task. In sum, our paradigm revealed a vital role of the R TPJ among other theory-of-mind regions during a triadic collaborative drawing task.

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Simultaneous fMRI and fast-scan cyclic voltammetry bridges oxygenation and neurotransmitter dynamics across spatiotemporal scales

10.1101/2021.05.28.446169 ◽

2021 ◽

Author(s):

Lindsay Walton ◽

Matthew Verber ◽

Sung-Ho Lee ◽

Tzu-Hao Harry Chao ◽

R. Mark Wightman ◽

...

Keyword(s):

Cyclic Voltammetry ◽

Electrochemical Techniques ◽

Brain Regions ◽

Blood Oxygenation ◽

Tissue Oxygen ◽

Spatiotemporal Resolution ◽

Fast Scan Cyclic Voltammetry ◽

Bold Fmri ◽

Time Courses ◽

Hemodynamic Information

The vascular contributions of neurotransmitters to the hemodynamic response are gaining more attention in neuroimaging studies, as many neurotransmitters are vasomodulatory. To date, well-established electrochemical techniques that detect neurotransmission in high magnetic field environments are limited. Here, we propose an experimental setting enabling simultaneous fast-scan cyclic voltammetry (FSCV) and blood oxygenation-dependent functional magnetic imaging (BOLD fMRI) to measure both local tissue oxygen and dopamine responses, and global BOLD changes, respectively. By using MR-compatible materials and the proposed data acquisition schemes, FSCV detected physiological analyte concentrations with high spatiotemporal resolution inside of a 9.4 T MRI bore. We found that tissue oxygen and BOLD correlate strongly, and brain regions that encode dopamine amplitude differences can be identified via modeling simultaneously acquired dopamine FSCV and BOLD fMRI time-courses. This technique provides complementary neurochemical and hemodynamic information and expands the scope of studying the influence of local neurotransmitter release over the entire brain.

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Temporal signal-to-noise changes in combined multiband- and slice-accelerated echo-planar imaging with a 20- and 64-channel coil

10.1101/641902 ◽

2019 ◽

Cited By ~ 1

Author(s):

Philipp Seidel ◽

Seth M. Levine ◽

Marlene Tahedl ◽

Jens V. Schwarzbach

Keyword(s):

Brain Regions ◽

Echo Planar Imaging ◽

Blood Oxygenation ◽

Receiver Coil ◽

Planar Imaging ◽

Signal To Noise ◽

Imaging Protocols ◽

Channel Coil ◽

Echo Planar ◽

The Brain

Echo planar imaging (EPI) is the most common method of functional magnetic resonance imaging for acquiring the blood oxygenation level-dependent (BOLD) contrast. One of the primary benefits of using EPI is that an entire volume of the brain can be acquired on the order of two seconds. However, this speed benefit comes with a cost. Because imaging protocols are limited by hardware (e.g., fast gradient switching), researchers are forced to compromise between spatial resolution, temporal resolution, or whole-brain coverage. Earlier attempts to circumvent this problem included developing protocols in which slices of a volume were acquired faster (i.e., slice (S) acceleration), while more recent protocols allow for multiple slices to be acquired simultaneously (i.e., multiband (MB) acceleration). However, applying such acceleration methods can lead to a reduction in the temporal signal-to-noise ratio (tSNR), which is a critical measure of the stability of the signal over time. Here we show, in five healthy subjects, using a 20- and 64-channel receiver coil, that enabling S-acceleration consistently yielded, as expected, a substantial decrease in tSNR, regardless of the receiver coil employed, whereas tSNR decrease resulting from MB acceleration was less pronounced. Specifically, with the 20-channel coil, tSNR of upto 4-fold MB-acceleration is comparable to that of no acceleration, while up to 6-fold MB-acceleration with the 64-channel coil yields comparable tSNR to that of no acceleration. Moreover, observed tSNR losses tended to be localized to temporal, insular, and medial brain regions and were more noticeable in the 20-than in the 64-channel coil. Conversely, with the 64-channel coil, the tSNR in lateral frontoparietal regions remained relatively stable with increasing MB factors. Such methodological explorations can inform researchers and clinicians as to how they can optimize imaging protocols depending on the available hardware and the brain regions they want to investigate.

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Growth of prefrontal and limbic brain regions and anxiety disorders in children born very preterm

Psychological Medicine ◽

10.1017/s0033291721002105 ◽

2021 ◽

pp. 1-12

Author(s):

Courtney P. Gilchrist ◽

Deanne K. Thompson ◽

Bonnie Alexander ◽

Claire E. Kelly ◽

Karli Treyvaud ◽

...

Keyword(s):

Anxiety Disorder ◽

Anxiety Disorders ◽

Orbitofrontal Cortex ◽

Developmental Trajectories ◽

Brain Regions ◽

Social Risk ◽

Intracranial Volume ◽

Total Brain Volume ◽

Very Preterm ◽

The Right

Abstract Background Children born very preterm (VP) display altered growth in corticolimbic structures compared with full-term peers. Given the association between the cortiocolimbic system and anxiety, this study aimed to compare developmental trajectories of corticolimbic regions in VP children with and without anxiety diagnosis at 13 years. Methods MRI data from 124 VP children were used to calculate whole brain and corticolimbic region volumes at term-equivalent age (TEA), 7 and 13 years. The presence of an anxiety disorder was assessed at 13 years using a structured clinical interview. Results VP children who met criteria for an anxiety disorder at 13 years (n = 16) displayed altered trajectories for intracranial volume (ICV, p < 0.0001), total brain volume (TBV, p = 0.029), the right amygdala (p = 0.0009) and left hippocampus (p = 0.029) compared with VP children without anxiety (n = 108), with trends in the right hippocampus (p = 0.062) and left medial orbitofrontal cortex (p = 0.079). Altered trajectories predominantly reflected slower growth in early childhood (0–7 years) for ICV (β = −0.461, p = 0.020), TBV (β = −0.503, p = 0.021), left (β = −0.518, p = 0.020) and right hippocampi (β = −0.469, p = 0.020) and left medial orbitofrontal cortex (β = −0.761, p = 0.020) and did not persist after adjusting for TBV and social risk. Conclusions Region- and time-specific alterations in the development of the corticolimbic system in children born VP may help to explain an increase in anxiety disorders observed in this population.

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On the Role of Bilateral Brain Hypofunction and Abnormal Lateralization of Cortical Information Flow as Neural Underpinnings of Conventional Metaphor Processing Impairment in Schizophrenia: An fMRI and EEG Study

Brain Topography ◽

10.1007/s10548-021-00849-x ◽

2021 ◽

Author(s):

Przemysław Adamczyk ◽

Martin Jáni ◽

Tomasz S. Ligeza ◽

Olga Płonka ◽

Piotr Błądziński ◽

...

Keyword(s):

Information Flow ◽

Language Processing ◽

Time Course ◽

Figurative Language ◽

Neural Circuits ◽

Effective Connectivity ◽

Brain Regions ◽

Blood Oxygenation ◽

Control Group ◽

Metaphor Processing

AbstractFigurative language processing (e.g. metaphors) is commonly impaired in schizophrenia. In the present study, we investigated the neural activity and propagation of information within neural circuits related to the figurative speech, as a neural substrate of impaired conventional metaphor processing in schizophrenia. The study included 30 schizophrenia outpatients and 30 healthy controls, all of whom were assessed with a functional Magnetic Resonance Imaging (fMRI) and electroencephalography (EEG) punchline-based metaphor comprehension task including literal (neutral), figurative (metaphorical) and nonsense (absurd) endings. The blood oxygenation level-dependent signal was recorded with 3T MRI scanner and direction and strength of cortical information flow in the time course of task processing was estimated with a 64-channel EEG input for directed transfer function. The presented results revealed that the behavioral manifestation of impaired figurative language in schizophrenia is related to the hypofunction in the bilateral fronto-temporo-parietal brain regions (fMRI) and various differences in effective connectivity in the fronto-temporo-parietal circuit (EEG). Schizophrenia outpatients showed an abnormal pattern of connectivity during metaphor processing which was related to bilateral (but more pronounced at the left hemisphere) hypoactivation of the brain. Moreover, we found reversed lateralization patterns, i.e. a rightward-shifted pattern during metaphor processing in schizophrenia compared to the control group. In conclusion, the presented findings revealed that the impairment of the conventional metaphor processing in schizophrenia is related to the bilateral brain hypofunction, which supports the evidence on reversed lateralization of the language neural network and the existence of compensatory recruitment of alternative neural circuits in schizophrenia.

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Transient Activity Induces a Long-Lasting Increase in the Excitability of Olfactory Bulb Interneurons

Journal of Neurophysiology ◽

10.1152/jn.00526.2007 ◽

2008 ◽

Vol 99 (1) ◽

pp. 187-199 ◽

Cited By ~ 8

Author(s):

Tsuyoshi Inoue ◽

Ben W. Strowbridge

Keyword(s):

Olfactory Bulb ◽

Granule Cells ◽

Receptor Activation ◽

Brain Regions ◽

Persistent Activity ◽

Cellular Mechanisms ◽

Calcium Dependent ◽

Transient Activity ◽

Olfactory Bulb Slices ◽

Processing And Storage

Little is known about the cellular mechanisms that underlie the processing and storage of sensory in the mammalian olfactory system. Here we show that persistent spiking, an activity pattern associated with working memory in other brain regions, can be evoked in the olfactory bulb by stimuli that mimic physiological patterns of synaptic input. We find that brief discharges trigger persistent activity in individual interneurons that receive slow, subthreshold oscillatory input in acute rat olfactory bulb slices. A 2- to 5-Hz oscillatory input, which resembles the synaptic drive that the olfactory bulb receives during sniffing, is required to maintain persistent firing. Persistent activity depends on muscarinic receptor activation and results from interactions between calcium-dependent afterdepolarizations and low-threshold Ca spikes in granule cells. Computer simulations suggest that intrinsically generated persistent activity in granule cells can evoke correlated spiking in reciprocally connected mitral cells. The interaction between the intrinsic currents present in reciprocally connected olfactory bulb neurons constitutes a novel mechanism for synchronized firing in subpopulations of neurons during olfactory processing.

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Dissociable oscillatory networks support gain and loss processing in human orbitofrontal cortex

10.1101/2021.02.25.432874 ◽

2021 ◽

Author(s):

Ignacio Saez ◽

Jack Lin ◽

Edward Chang ◽

Josef Parvizi ◽

Robert T. Knight ◽

...

Keyword(s):

Neural Activity ◽

Orbitofrontal Cortex ◽

Low Frequency ◽

Brain Regions ◽

Reward Processing ◽

Neural Oscillations ◽

Beta Band ◽

Neuronal Ensembles ◽

Gain And Loss

AbstractHuman neuroimaging and animal studies have linked neural activity in orbitofrontal cortex (OFC) to valuation of positive and negative outcomes. Additional evidence shows that neural oscillations, representing the coordinated activity of neuronal ensembles, support information processing in both animal and human prefrontal regions. However, the role of OFC neural oscillations in reward-processing in humans remains unknown, partly due to the difficulty of recording oscillatory neural activity from deep brain regions. Here, we examined the role of OFC neural oscillations (<30Hz) in reward processing by combining intracranial OFC recordings with a gambling task in which patients made economic decisions under uncertainty. Our results show that power in different oscillatory bands are associated with distinct components of reward evaluation. Specifically, we observed a double dissociation, with a selective theta band oscillation increase in response to monetary gains and a beta band increase in response to losses. These effects were interleaved across OFC in overlapping networks and were accompanied by increases in oscillatory coherence between OFC electrode sites in theta and beta band during gain and loss processing, respectively. These results provide evidence that gain and loss processing in human OFC are supported by distinct low-frequency oscillations in networks, and provide evidence that participating neuronal ensembles are organized functionally through oscillatory coherence, rather than local anatomical segregation.

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Brain Activation of College Students in China With Premenstrual Syndrome Localized by BOLD-fMRI

10.21203/rs.3.rs-568217/v1 ◽

2021 ◽

Author(s):

Dongmei Gao ◽

Mingzhou Gao ◽

Li An ◽

Yanhong Yu ◽

Jieqiong Wang ◽

...

Keyword(s):

College Students ◽

Premenstrual Syndrome ◽

Brain Area ◽

Inferior Frontal Gyrus ◽

Brain Regions ◽

Anterior Lobe ◽

Middle Temporal Gyrus ◽

Cerebellar Tonsil ◽

Bold Fmri ◽

Significant Difference

Abstract Background: Most studies on the mechanism behind premenstrual syndrome (PMS) have focused on fluctuating hormones, but little evidence exists regarding functional abnormalities in the affected brain regions of college students. Thus, the aim of this study is to localize PMS's abnormal brain regions by BOLD-fMRI in college students.Methods: Thirteen PMS patients and fifteen healthy control (HC) subjects underwent a BOLD-fMRI scan during the luteal phase induced by depressive emotion pictures. The BOLD-fMRI data were processed by SPM 8 software and rest software based on MATLAB platform. Each cluster volume threshold (cluster) was greater than 389 continuous voxels, and the brain area with single voxel threshold P < 0.05 (after correction) was defined as the area with a significant difference. The emotion report form and the instruction implementation checklist were used to evaluate the emotion induced by picture.Results: Compared to the HC, right inferior occipital gyrus, right middle occipital gyrus, right lingual gyrus, right fusiform gyrus, right inferior temporal gyrus, cerebelum_crus1_R，cerebelum_6_R, culmen, the cerebellum anterior lobe, tuber, cerebellar tonsil of PMS patients were enhanced activation. Sub-lobar，sub-gyral，extra-nuclear，right orbit part of superior frontal gyrus, right middle temporal gyrus, right Orbit part of inferior frontal gyrus, limbic lobe, right insula, bilateral anterior and adjacent cingulate gyrus, bilateral caudate, caudate head, bilateral putamen, left globus pallidus were decreased activation.Conclusion: Our findings may improve our understanding of the neural mechanisms involved in PMS.

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