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

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.

scholarly journals Optogenetic activation of SST-positive interneurons restores hippocampal theta oscillation impairment induced by soluble amyloid beta oligomersin vivo

2018 ◽  
Author(s):  
Hyowon Chung ◽  
Kyerl Park ◽  
Hyun Jae Jang ◽  
Michael M Kohl ◽  
Jeehyun Kwag
Keyword(s):  
Learning And Memory ◽  
Peak Power ◽  
Pyramidal Neurons ◽  
Hippocampal Slices ◽  
Field Potential ◽  
Theta Oscillations ◽  
Ca1 Pyramidal Neurons ◽  
Theta Frequency ◽  
Hippocampal Theta

AbstractAbnormal accumulation of amyloid β oligomers (AβO) is a hallmark of Alzheimer’s disease (AD), which leads to learning and memory deficits. Hippocampal theta oscillations that are critical in spatial navigation, learning and memory are impaired in AD. Since GABAergic interneurons, such as somatostatin-positive (SST+) and parvalbumin-positive (PV+) interneurons, are believed to play key roles in the hippocampal oscillogenesis, we asked whether AβO selectively impairs these SST+ and PV+ interneurons. To selectively manipulate SST+ or PV+ interneuron activity in mice with AβO pathologyin vivo, we co-injected AβO and adeno-associated virus (AAV) for expressing floxed channelrhodopsin-2 (ChR2) into the hippocampus of SST-Cre or PV-Cre mice. Local field potential (LFP) recordingsin vivoin these AβO–injected mice showed a reduction in the peak power of theta oscillations and desynchronization of spikes from CA1 pyramidal neurons relative to theta oscillations compared to those in control mice. Optogenetic-activation of SST+ but not PV+ interneurons in AβO–injected mice fully restored the peak power of theta oscillations and resynchronized the theta spike phases to a level observed in control mice.In vitrowhole-cell voltage-clamp recordings in CA1 pyramidal neurons in hippocampal slices treated with AβO revealed that short-term plasticity of SST+ interneuron inhibitory inputs to CA1 pyramidal neurons at theta frequency were selectively disrupted while that of PV+ interneuron inputs were unaffected. Together, our results suggest that dysfunction in inputs from SST+ interneurons to CA1 pyramidal neurons may underlie the impairment of theta oscillations observed in AβO-injected micein vivo.Our findings identify SST+ interneurons as a target for restoring theta-frequency oscillations in early AD.

scholarly journals Nasal respiration is necessary for ketamine-dependent high frequency network oscillations and behavioral hyperactivity in rats

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jacek Wróbel ◽  
Władysław Średniawa ◽  
Gabriela Jurkiewicz ◽  
Jarosław Żygierewicz ◽  
Daniel K. Wójcik ◽  
...  
Keyword(s):  
High Frequency ◽  
Ventral Striatum ◽  
Behavioral Activation ◽  
Brain Regions ◽  
Basal Respiration ◽  
Oscillatory Activity ◽  
Nasal Airflow ◽  
High Frequency Oscillations ◽  
Theta Frequency ◽  
Freely Moving

Abstract Changes in oscillatory activity are widely reported after subanesthetic ketamine, however their mechanisms of generation are unclear. Here, we tested the hypothesis that nasal respiration underlies the emergence of high-frequency oscillations (130–180 Hz, HFO) and behavioral activation after ketamine in freely moving rats. We found ketamine 20 mg/kg provoked “fast” theta sniffing in rodents which correlated with increased locomotor activity and HFO power in the OB. Bursts of ketamine-dependent HFO were coupled to “fast” theta frequency sniffing. Theta coupling of HFO bursts were also found in the prefrontal cortex and ventral striatum which, although of smaller amplitude, were coherent with OB activity. Haloperidol 1 mg/kg pretreatment prevented ketamine-dependent increases in fast sniffing and instead HFO coupling to slower basal respiration. Consistent with ketamine-dependent HFO being driven by nasal respiration, unilateral naris blockade led to an ipsilateral reduction in ketamine-dependent HFO power compared to the control side. Bilateral nares blockade reduced ketamine-induced hyperactivity and HFO power and frequency. These findings suggest that nasal airflow entrains ketamine-dependent HFO in diverse brain regions, and that the OB plays an important role in the broadcast of this rhythm.

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

2019 ◽  
Author(s):  
Hio-Been Han ◽  
Ka Eun Lee ◽  
Jee Hyun Choi
Keyword(s):  
Long Range ◽  
Sustained Attention ◽  
Brain Regions ◽  
Theta Oscillations ◽  
Behavioral Correlates ◽  
Contradictory Behavior ◽  
Visual Cortices ◽  
Cortical Regions ◽  
Phase Amplitude ◽  
Term Performance

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.

scholarly journals Identifying regions in prefrontal cortex related to working memory improvement: a novel meta-analytic method using electric field modeling

2021 ◽  
Author(s):  
Miles Wischnewski ◽  
Kathleen E. Mantell ◽  
Alexander Opitz
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Electric Fields ◽  
Brain Regions ◽  
Medium Effect ◽  
Analytic Method ◽  
List Type

AbstractAltering cortical activity using transcranial direct current stimulation (tDCS) has been shown to improve working memory (WM) performance. Due to large inter-experimental variability in the tDCS montage configuration and strength of induced electric fields, results have been mixed. Here, we present a novel meta-analytic method relating behavioral effect sizes to electric field strength to identify brain regions underlying largest tDCS-induced WM improvement. Simulations on 69 studies targeting left prefrontal cortex showed that tDCS electric field strength in lower dorsolateral prefrontal cortex (Brodmann area 45/47) relates most strongly to improved WM performance. This region explained 7.8% of variance, equaling a medium effect. A similar region was identified when correlating WM performance and electric field strength of right prefrontal tDCS studies (n = 18). Maximum electric field strength of five previously used tDCS configurations were outside of this location. We thus propose a new tDCS montage which maximizes the tDCS electric field strength in that brain region. Our findings can benefit future tDCS studies that aim to affect WM function.Highlights-We summarize the effect of 87 tDCS studies on working memory performance-We introduce a new meta-analytic method correlating tDCS electric fields and performance-tDCS-induced electric fields in lower DLPFC correlate significantly with improved working memory-The lower DLPFC was not maximally targeted by most tDCS montages and we provide an optimized montage

A Large-scale Neurocomputational Model of Task-oriented Behavior Selection and Working Memory in Prefrontal Cortex

2006 ◽  
Vol 18 (2) ◽  
pp. 242-257 ◽  
Author(s):  
George L. Chadderdon ◽  
Olaf Sporns
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Large Scale ◽  
Memory Task ◽  
Brain Regions ◽  
Synaptic Activity ◽  
Dynamic State ◽  
Memory Representation ◽  
Behavioral Repertoire ◽  
Behavior Selection

The prefrontal cortex (PFC) is crucially involved in the executive component of working memory, representation of task state, and behavior selection. This article presents a large-scale computational model of the PFC and associated brain regions designed to investigate the mechanisms by which working memory and task state interact to select adaptive behaviors from a behavioral repertoire. The model consists of multiple brain regions containing neuronal populations with realistic physiological and anatomical properties, including extrastriate visual cortical regions, the inferotemporal cortex, the PFC, the striatum, and midbrain dopamine (DA) neurons. The onset of a delayed match-to-sample or delayed nonmatch-to-sample task triggers tonic DA release in the PFC causing a switch into a persistent, stimulus-insensitive dynamic state that promotes the maintenance of stimulus representations within prefrontal networks. Other modeled prefrontal and striatal units select cognitive acceptance or rejection behaviors according to which task is active and whether prefrontal working memory representations match the current stimulus. Working memory task performance and memory fields of prefrontal delay units are degraded by extreme elevation or depletion of tonic DA levels. Analyses of cellular and synaptic activity suggest that hyponormal DA levels result in increased prefrontal activation, whereas hypernormal DA levels lead to decreased activation. Our simulation results suggest a range of predictions for behavioral, single-cell, and neuroimaging response data under the proposed task set and under manipulations of DA concentration.

scholarly journals Nasal respiration is necessary for the emergence of ketamine-induced high frequency network oscillations and behavioral hyperactivity in freely moving rats

2020 ◽  
Author(s):  
Jacek Wróbel ◽  
Władysław Średniawa ◽  
Gabriela Bernatowicz ◽  
Jaroslaw Zygierewicz ◽  
Daniel K Wójcik ◽  
...  
Keyword(s):  
High Frequency ◽  
Behavioral Activation ◽  
Brain Regions ◽  
Basal Respiration ◽  
Oscillatory Activity ◽  
High Frequency Oscillations ◽  
Freely Moving Rats ◽  
Theta Frequency ◽  
Freely Moving ◽  
Subcortical Regions

AbstractChanges in oscillatory activity are widely reported after subanesthetic ketamine, however their mechanisms of generation are unclear. Here, we tested the hypothesis that nasal respiration underlies the emergence of high-frequency oscillations (130-180 Hz, HFO) and behavioral activation after ketamine in freely moving rats. We found ketamine 20 mg/kg provoked “fast” theta sniffing in rodents which correlated with increased locomotor activity and HFO power in the OB. Bursts of ketamine-dependent HFO were coupled to “fast” theta frequency sniffing. Theta coupling of HFO bursts were also found in the prefrontal cortex and ventral striatum which, although of smaller amplitude, were in phase with OB activity. Haloperidol 1 mg/kg pretreatment prevented ketamine-dependent increases in fast sniffing and instead HFO coupling to slower basal respiration. Consistent with ketamine-dependent HFO being driven by nasal respiration, unilateral naris blockade led to an ipsilateral reduction in ketamine-dependent HFO power compared to the control side. Bilateral nares blockade reduced ketamine-induced hyperactivity and HFO power and frequency. In conclusion, nasal entrainment of ketamine-dependent HFO across cortical and subcortical regions at theta frequencies represents a mechanism of orchestrated neural activity across distinct brain regions. The dense divergent connectivity of the olfactory system serves to broadcast this HFO to limbic areas.

scholarly journals Layer-dependent activity in human prefrontal cortex during working memory

2018 ◽  
Author(s):  
Emily S. Finn ◽  
Laurentius Huber ◽  
David C. Jangraw ◽  
Peter A. Bandettini
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Memory Task ◽  
Brain Regions ◽  
Cognitive Information Processing ◽  
Dependent Activity ◽  
Dorsolateral Prefrontal ◽  
Cognitive Information ◽  
Series Of Functions ◽  
Layer Specificity

Working memory involves a series of functions: encoding a stimulus, maintaining or manipulating its representation over a delay, and finally making a behavioral response. While working memory engages dorsolateral prefrontal cortex (dlPFC), few studies have investigated whether these subfunctions are localized to different cortical depths in this region, and none have done so in humans. Here, we use high-resolution functional MRI to interrogate the layer specificity of neural activity during different epochs of a working memory task in dlPFC. We detect activity timecourses that follow the hypothesized patterns: superficial layers are preferentially active during the delay period, while deeper layers are preferentially active during the response. Results demonstrate that layer-specific fMRI can be used in higher-order brain regions to non-invasively map cognitive information processing along cortical circuitry in humans.

scholarly journals Dynamic shifts of visual and saccadic signals in prefrontal cortical regions 8Ar and FEF

2019 ◽  
Author(s):  
Sanjeev B. Khanna ◽  
Jonathan A. Scott ◽  
Matthew A. Smith
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Spatial Working Memory ◽  
Active Vision ◽  
Brain Regions ◽  
Motor Tasks ◽  
Prefrontal Cortical ◽  
Spatial Registration ◽  
Cortical Regions ◽  
Spatial Locations

AbstractActive vision is a fundamental process by which primates gather information about the external world. Multiple brain regions have been studied in the context of simple active vision tasks in which a visual target’s appearance is temporally separated from saccade execution. Most neurons have tight spatial registration between visual and saccadic signals, and in areas such as prefrontal cortex (PFC) some neurons show persistent delay activity that links visual and motor epochs and has been proposed as a basis for spatial working memory. Many PFC neurons also show rich dynamics, which have been attributed to alternative working memory codes and the representation of other task variables. Our study investigated the transition between processing a visual stimulus and generating an eye movement in populations of PFC neurons in macaque monkeys performing a memory guided saccade task. We found that neurons in two subregions of PFC, the frontal eye fields (FEF) and area 8Ar, differed in their dynamics and spatial response profiles. These dynamics could be attributed largely to shifts in the spatial profile of visual and motor responses in individual neurons. This led to visual and motor codes for particular spatial locations that were instantiated by different mixtures of neurons, which could be important in PFC’s flexible role in multiple sensory, cognitive, and motor tasks.New and NoteworthyA central question in neuroscience is how the brain transitions from sensory representations to motor outputs. The prefrontal cortex contains neurons that have long been implicated as important in this transition and in working memory. We found evidence for rich and diverse tuning in these neurons, that was often spatially misaligned between visual and saccadic responses. This feature may play an important role in flexible working memory capabilities.

Cellular Mechanisms of Psychotic Disorders

2017 ◽  
Author(s):  
Samuel J. Dienel ◽  
David A. Lewis
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Psychotic Disorders ◽  
Pyramidal Cells ◽  
Oscillatory Activity ◽  
Gamma Aminobutyric Acid ◽  
Cellular Mechanisms ◽  
Memory Impairments ◽  
Gaba Neuron

Cognitive dysfunction in schizophrenia, including disturbances in working memory, is a core feature of the illness and the best predictor of long-term functional outcome. Working memory relies on neural network oscillations in the prefrontal cortex. Gamma-aminobutyric acid (GABA) neurons in the prefrontal cortex, which are crucial for this oscillatory activity, exhibit a number of alterations in individuals diagnosed with schizophrenia. These GABA neuron disturbances may be secondary to upstream alterations in excitatory pyramidal cells in the prefrontal cortex. Together, these findings suggest both a neural substrate for working memory impairments in schizophrenia and therapeutic targets for improving functional outcomes in this patient population.

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