Functional dissociation of theta oscillations in the frontal and visual cortices and their long-range network during sustained attention

ABSTRACTTheta-band (4–12 Hz) activities in the frontal cortex have been thought to be a key mechanism of sustained attention and goal-related behaviors, forming a phase-coherent network with task-related sensory cortices for integrated neuronal ensembles. However, recent visual task studies found that selective attention attenuates stimulus-related theta power in the visual cortex, suggesting a functional dissociation of cortical theta oscillations. To investigate this contradictory behavior of cortical theta, a visual Go/No-Go task was performed with electroencephalogram recording in mice. During the No-Go period, transient theta oscillations were observed in both the frontal and visual cortices, but theta oscillations of the two areas were prominent in different trial epochs. By separating trial epochs based on subjects’ short-term performance, we found that frontal theta was prominent in good-performance epochs, while visual theta was prominent in bad-performance epochs, exhibiting a functional dissociation of cortical theta rhythms. Furthermore, the two theta rhythms also showed a heterogeneous pattern of phase-amplitude coupling with fast oscillations, reflecting their distinct architecture in underlying neuronal circuitry. Interestingly, in good-performance epochs, where visual theta was relatively weak, stronger fronto-visual long-range synchrony and shorter posterior-to-anterior temporal delay were found. These findings highlight a previously overlooked aspect of long-range synchrony between distinct oscillatory entities in the cerebral cortex and provide empirical evidence of a functional dissociation of cortical theta rhythms.IN BRIEFPrevious literature emphasized the pro-cognitive role of coherent oscillatory networks between distal brain regions, such as the fronto-visual theta synchrony. However, such a conceptual framework has been challenged as recent findings revealed distinct behavioral correlates of theta oscillations found in different cortical regions, especially in the frontal and visual cortices. Here, we show that frontal and visual theta represent distinct cortical processes and that the functional connectivity between them increases during sustained attention, especially when one of the two theta rhythms is relatively suppressed. The data presented here highlight a novel aspect of neural long-range synchrony between distinct cortical oscillators with distinct functional significance in task performance.

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Theta oscillations in the prefrontal-hippocampal circuit do not couple to respiration-related oscillations

10.1101/2021.12.22.473834 ◽

2021 ◽

Author(s):

Sunandha Srikanth ◽

Dylan Le ◽

Yudi Hu ◽

Jill K Leutgeb ◽

Stefan Leutgeb

Keyword(s):

Working Memory ◽

Prefrontal Cortex ◽

Learning And Memory ◽

Long Range ◽

Brain Regions ◽

Theta Oscillations ◽

Oscillatory Activity ◽

Low Coherence ◽

Theta Frequency ◽

Neural Computations

Oscillatory activity is thought to coordinate neural computations across brain regions, and theta oscillations are critical for learning and memory. Because the frequency of respiratory-related oscillations (RROs) in rodents can overlap with the frequency of theta in the prefrontal cortex (PFC) and the hippocampus, we asked whether odor-cued working memory may be supported by coupling between these two oscillations. We first confirmed that RROs are propagated to the hippocampus and PFC and that RRO frequency overlaps with canonical theta frequency. However, we found low coherence between RROs and local theta oscillations in the hippocampus-PFC network when the two types of oscillations overlapped in frequency. This effect was observed during all behavioral phases including during movement and while odors were actively sampled when stationary. Despite the similarity in frequency, RROs and theta oscillations therefore appear to be limited to supporting computation in distinct networks, which suggests that sustained long-range coordination between oscillation patterns that depend on separate pacemakers is not necessary to support at least one type of working memory.

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Functional Dissociation of θ Oscillations in the Frontal and Visual Cortices and Their Long-Range Network during Sustained Attention

eNeuro ◽

10.1523/eneuro.0248-19.2019 ◽

2019 ◽

Vol 6 (6) ◽

pp. ENEURO.0248-19.2019 ◽

Cited By ~ 4

Author(s):

Hio-Been Han ◽

Ka Eun Lee ◽

Jee Hyun Choi

Keyword(s):

Long Range ◽

Sustained Attention ◽

Visual Cortices

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Instantaneous amplitude and shape of postrhinal theta oscillations differentially encode running speed

10.1101/2020.06.03.130609 ◽

2020 ◽

Author(s):

Megha Ghosh ◽

Benjamin E. Shanahan ◽

Sharon C. Furtak ◽

George A. Mashour ◽

Rebecca D. Burwell ◽

...

Keyword(s):

Theta Oscillations ◽

Instantaneous Amplitude ◽

Single Cycle ◽

Running Speed ◽

Behavioral Correlates ◽

Temporal Asymmetry ◽

Rapid Changes ◽

Postrhinal Cortex ◽

Cortical Regions ◽

Hippocampal Theta

ABSTRACTHippocampal theta oscillations have a temporally asymmetric waveform shape, but it is not known if this theta asymmetry extends to all other cortical regions involved in spatial navigation and memory. Here, using both established and improved cycle-by-cycle analysis methods, we show that theta waveforms in the postrhinal cortex are also temporally asymmetric. On average, the falling phase of postrhinal theta cycles lasts longer than the subsequent rising phase. There are, however, rapid changes in both the instantaneous amplitude and instantaneous temporal asymmetry of postrhinal theta cycles. These rapid changes in amplitude and asymmetry are very poorly correlated, indicative of a mechanistic disconnect between these theta cycle features. We show that the instantaneous amplitude and asymmetry of postrhinal theta cycles differentially encode running speed. Although theta amplitude continues to increase at the fastest running speeds, temporal asymmetry of the theta waveform shape plateaus after medium speeds. Our results suggest that the amplitude and waveform shape of individual postrhinal theta cycles may be governed by partially independent mechanisms and emphasize the importance of employing a single cycle approach to understanding the genesis and behavioral correlates of cortical theta rhythms.

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Cochlear activity in silent cue-target intervals shows a theta-rhythmic pattern and is correlated to attentional alpha and theta modulations

BMC Biology ◽

10.1186/s12915-021-00992-8 ◽

2021 ◽

Vol 19 (1) ◽

Author(s):

Moritz Herbert Albrecht Köhler ◽

Gianpaolo Demarchi ◽

Nathan Weisz

Keyword(s):

Selective Attention ◽

Brain Regions ◽

Attentional Focus ◽

Theta Activity ◽

Superior Olivary Complex ◽

Rhythmic Pattern ◽

Auditory Input ◽

Auditory Selective Attention ◽

Beta Power ◽

Cortical Regions

AbstractBackgroundA long-standing debate concerns where in the processing hierarchy of the central nervous system (CNS) selective attention takes effect. In the auditory system, cochlear processes can be influenced via direct and mediated (by the inferior colliculus) projections from the auditory cortex to the superior olivary complex (SOC). Studies illustrating attentional modulations of cochlear responses have so far been limited to sound-evoked responses. The aim of the present study is to investigate intermodal (audiovisual) selective attention in humans simultaneously at the cortical and cochlear level during a stimulus-free cue-target interval.ResultsWe found that cochlear activity in the silent cue-target intervals was modulated by a theta-rhythmic pattern (~ 6 Hz). While this pattern was present independently of attentional focus, cochlear theta activity was clearly enhanced when attending to the upcoming auditory input. On a cortical level, classical posterior alpha and beta power enhancements were found during auditory selective attention. Interestingly, participants with a stronger release of inhibition in auditory brain regions show a stronger attentional modulation of cochlear theta activity.ConclusionsThese results hint at a putative theta-rhythmic sampling of auditory input at the cochlear level. Furthermore, our results point to an interindividual variable engagement of efferent pathways in an attentional context that are linked to processes within and beyond processes in auditory cortical regions.

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Physical positioning markedly enhances brain transduction after intrathecal AAV9 infusion

Science Advances ◽

10.1126/sciadv.aau9859 ◽

2018 ◽

Vol 4 (11) ◽

pp. eaau9859 ◽

Cited By ~ 7

Author(s):

Michael J. Castle ◽

Yuhsiang Cheng ◽

Aravind Asokan ◽

Mark H. Tuszynski

Keyword(s):

Gene Expression ◽

Gene Delivery ◽

Neurological Disorders ◽

Fold Increase ◽

Brain Regions ◽

Intrathecal Administration ◽

Simple Method ◽

Virus Serotype ◽

Cortical Regions ◽

The Brain

Several neurological disorders may benefit from gene therapy. However, even when using the lead vector candidate for intrathecal administration, adeno-associated virus serotype 9 (AAV9), the strength and distribution of gene transfer to the brain are inconsistent. On the basis of preliminary observations that standard intrathecal AAV9 infusions predominantly drive reporter gene expression in brain regions where gravity might cause cerebrospinal fluid to settle, we tested the hypothesis that counteracting vector “settling” through animal positioning would enhance vector delivery to the brain. When rats are either inverted in the Trendelenburg position or continuously rotated after intrathecal AAV9 infusion, we find (i) a significant 15-fold increase in the number of transduced neurons, (ii) a marked increase in gene delivery to cortical regions, and (iii) superior animal-to-animal consistency of gene expression. Entorhinal, prefrontal, frontal, parietal, hippocampal, limbic, and basal forebrain neurons are extensively transduced: 95% of transduced cells are neurons, and greater than 70% are excitatory. These findings provide a novel and simple method for broad gene delivery to the cortex and are of substantial relevance to translational programs for neurological disorders, including Alzheimer’s disease and related dementias, stroke, and traumatic brain injury.

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Hyper-attenuating brain lesions on CT after ischemic stroke and thrombectomy are associated with final brain infarction

Interventional Neuroradiology ◽

10.1177/1591019917729550 ◽

2017 ◽

Vol 23 (6) ◽

pp. 594-600 ◽

Cited By ~ 4

Author(s):

FB Cabral ◽

LH Castro-Afonso ◽

GS Nakiri ◽

LM Monsignore ◽

SRC Fábio ◽

...

Keyword(s):

Ischemic Stroke ◽

Endovascular Treatment ◽

Brain Infarction ◽

Internal Capsule ◽

Brain Regions ◽

Hemorrhagic Transformation ◽

Anterior Circulation ◽

Caudate Nuclei ◽

Predictive Values ◽

Cortical Regions

Purpose Hyper-attenuating lesions, or contrast staining, on a non-contrast brain computed tomography (NCCT) scan have been investigated as a predictor for hemorrhagic transformation after endovascular treatment of acute ischemic stroke (AIS). However, the association of hyper-attenuating lesions and final ischemic areas are poorly investigated in this setting. The aim of the present study was to assess correlations between hyper-attenuating lesions and final brain infarcted areas after thrombectomy for AIS. Methods Data from patients with AIS of the anterior circulation who underwent endovascular treatment were retrospectively assessed. Images of the brain NCCT scans were analyzed in the first hours and late after treatment. The hyper-attenuating areas were compared to the final ischemic areas using the Alberta Stroke Program Early CT Score (ASPECTS). Results Seventy-one of the 123 patients (65.13%) treated were included. The association between the hyper-attenuating region in the post-thrombectomy CT scan and final brain ischemic area were sensitivity (58.3% to 96.9%), specificity (42.9% to 95.6%), positive predictive values (71.4% to 97.7%), negative predictive values (53.8% to 79.5%), and accuracy values (68% to 91%). The highest sensitivity values were found for the lentiform (96.9%) and caudate nuclei (80.4%) and for the internal capsule (87.5%), and the lowest values were found for the M1 (58.3%) and M6 (66.7%) cortices. Conclusions Hyper-attenuating lesions on head NCCT scans performed after endovascular treatment of AIS may predict final brain infarcted areas. The prediction appears to be higher in the deep brain regions compared with the cortical regions.

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Fronto-striatal atrophy correlates of neuropsychiatric dysfunction in frontotemporal dementia (FTD) and Alzheimer's disease (AD)

Dementia & Neuropsychologia ◽

10.1590/s1980-57642013dn70100012 ◽

2013 ◽

Vol 7 (1) ◽

pp. 75-82 ◽

Cited By ~ 9

Author(s):

Dong Seok Yi ◽

Maxime Bertoux ◽

Eneida Mioshi ◽

John R. Hodges ◽

Michael Hornberger

Keyword(s):

Frontotemporal Dementia ◽

Rating Scale ◽

Brain Regions ◽

Abnormal Behaviour ◽

Behavioural Symptoms ◽

Visual Rating ◽

Prefrontal Cortical ◽

Mri Scans ◽

Visual Rating Scale ◽

Cortical Regions

ABSTRACT Behavioural disturbances in frontotemporal dementia (FTD) are thought to reflect mainly atrophy of cortical regions. Recent studies suggest that subcortical brain regions, in particular the striatum, are also significantly affected and this pathology might play a role in the generation of behavioural symptoms. Objective: To investigate prefrontal cortical and striatal atrophy contributions to behavioural symptoms in FTD. Methods: One hundred and eighty-two participants (87 FTD patients, 39 AD patients and 56 controls) were included. Behavioural profiles were established using the Cambridge Behavioural Inventory Revised (CBI-R) and Frontal System Behaviour Scale (FrSBe). Atrophy in prefrontal (VMPFC, DLPFC) and striatal (caudate, putamen) regions was established via a 5-point visual rating scale of the MRI scans. Behavioural scores were correlated with atrophy rating scores. Results: Behavioural and atrophy ratings demonstrated that patients were significantly impaired compared to controls, with bvFTD being most severely affected. Behavioural-anatomical correlations revealed that VMPFC atrophy was closely related to abnormal behaviour and motivation disturbances. Stereotypical behaviours were associated with both VMPFC and striatal atrophy. By contrast, disturbance of eating was found to be related to striatal atrophy only. Conclusion: Frontal and striatal atrophy contributed to the behavioural disturbances seen in FTD, with some behaviours related to frontal, striatal or combined fronto-striatal pathology. Consideration of striatal contributions to the generation of behavioural disturbances should be taken into account when assessing patients with potential FTD.

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Effects of amnesia on processing in the hippocampus and default mode network during a naturalistic memory task: a case study

10.31234/osf.io/e9n8c ◽

2018 ◽

Author(s):

Christiane Oedekoven ◽

James L. Keidel ◽

Stuart Anderson ◽

Angus Nisbet ◽

Chris Bird

Keyword(s):

Functional Connectivity ◽

Episodic Memory ◽

Memory Performance ◽

Memory Task ◽

Structural Mri ◽

Brain Regions ◽

Left Hippocampus ◽

Cortical Regions ◽

The Right ◽

Encoding And Retrieval

Despite their severely impaired episodic memory, individuals with amnesia are able to comprehend ongoing events. Online representations of a current event are thought to be supported by a network of regions centred on the posterior midline cortex (PMC). By contrast, episodic memory is widely believed to be supported by interactions between the hippocampus and these cortical regions. In this MRI study, we investigated the encoding and retrieval of lifelike events (video clips) in a patient with severe amnesia likely resulting from a stroke to the right thalamus, and a group of 20 age-matched controls. Structural MRI revealed grey matter reductions in left hippocampus and left thalamus in comparison to controls. We first characterised the regions activated in the controls while they watched and retrieved the videos. There were no differences in activation between the patient and controls in any of the regions. We then identified a widespread network of brain regions, including the hippocampus, that were functionally connected with the PMC in controls. However, in the patient there was a specific reduction in functional connectivity between the PMC and a region of left hippocampus when both watching and attempting to retrieve the videos. A follow up analysis revealed that in controls the functional connectivity between these regions when watching the videos was correlated with memory performance. Taken together, these findings support the view that the interactions between the PMC and the hippocampus enable the encoding and retrieval of multimodal representations of the contents of an event.

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Mind wandering and attention during focused meditation: A fine-grained temporal analysis of fluctuating cognitive states

10.31231/osf.io/4fnt6 ◽

2017 ◽

Author(s):

Wendy Hasenkamp ◽

Christine Wilson-Mendenhall ◽

Erica Duncan ◽

Lawrence Barsalou

Keyword(s):

Cognitive Processes ◽

Sustained Attention ◽

Temporal Analysis ◽

Mind Wandering ◽

Brain Regions ◽

Attentional Processing ◽

Default Mode ◽

Cognitive Correlates ◽

Cognitive States ◽

Task Positive Network

Studies have suggested that the default mode network is active during mind wandering, which is often experienced intermittently during sustained attention tasks. Conversely, an anticorrelated task-positive network is thought to subserve various forms of attentional processing. Understanding how these two systems work together is central for understanding many forms of optimal and sub-optimal task performance. Here we present a basic model of naturalistic cognitive fluctuations between mind wandering and attentional states derived from the practice of focused attention meditation. This model proposes four intervals in a cognitive cycle: mind wandering, awareness of mind wandering, shifting of attention, and sustained attention. People who train in this style of meditation cultivate their abilities to monitor cognitive processes related to attention and distraction, making them well suited to report on these mental events. Fourteen meditation practitioners performed breath-focused meditation while undergoing fMRI scanning. When participants realized their mind had wandered, they pressed a button and returned their focus to the breath. The four intervals above were then constructed around these button presses. We hypothesized that periods of mind wandering would be associated with default mode activity, whereas cognitive processes engaged during awareness of mind wandering, shifting of attention and sustained attention would engage attentional subnetworks. Analyses revealed activity in brain regions associated with the default mode during mind wandering, and in salience network regions during awareness of mind wandering. Elements of the executive network were active during shifting and sustained attention. Furthermore, activations during these cognitive phases were modulated by lifetime meditation experience. These findings support and extend theories about cognitive correlates of distributed brain networks.

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