scholarly journals Organization and engagement of a prefrontal-olfactory network during olfactory selective attention

2021 ◽  
Author(s):  
Hillary L Cansler ◽  
Estelle E in 't Zandt ◽  
Kaitlin S. Carlson ◽  
Waseh T Khan ◽  
Minghong Ma ◽  
...  
Keyword(s):  
Selective Attention ◽  
Gamma Oscillations ◽  
Brain Regions ◽  
Field Potentials ◽  
Active Sampling ◽  
Attention Task ◽  
Gamma Power ◽  
Theta Phase ◽  
To Receive ◽  
The Brain

Sensory perception is profoundly shaped by attention. Attending to an odor strongly regulates if and how a smell is perceived – yet the brain systems involved in this process are unknown. Here we report integration of the medial prefrontal cortex (mPFC), a collection of brain regions integral to attention, with the olfactory system in the context of selective attention to odors. First, we used tracing methods to establish the tubular striatum (TuS, also known as the olfactory tubercle) as the primary olfactory region to receive direct mPFC input in rats. Next, we recorded local field potentials from the olfactory bulb (OB), mPFC, and TuS while rats completed an olfactory selective attention task. Gamma power and coupling of gamma oscillations with theta phase were consistently high as rats flexibly switched their attention to odors. Beta and theta synchrony between mPFC and olfactory regions were elevated as rats switched their attention to odors. Finally, we found that sniffing was consistent despite shifting attentional demands, suggesting that the mPFC-OB theta coherence is independent of changes in active sampling. Together, these findings begin to define an olfactory attention network wherein mPFC activity, as well as that within olfactory regions, are coordinated in manners based upon attentional states.

Reward-Associated Gamma Oscillations in Ventral Striatum Are Regionally Differentiated and Modulate Local Firing Activity

2010 ◽  
Vol 103 (3) ◽  
pp. 1658-1672 ◽  
Author(s):  
Tobias Kalenscher ◽  
Carien S. Lansink ◽  
Jan V. Lankelma ◽  
Cyriel M. A. Pennartz
Keyword(s):  
Ventral Striatum ◽  
Phase Locking ◽  
Gamma Oscillations ◽  
Brain Regions ◽  
Reward Processing ◽  
Temporal Organization ◽  
Gamma Activity ◽  
Neural Ensembles ◽  
Gamma Range ◽  
Gamma Power

Oscillations of local field potentials (LFPs) in the gamma range are found in many brain regions and are supposed to support the temporal organization of cognitive, perceptual, and motor functions. Even though gamma oscillations have also been observed in ventral striatum, one of the brain's most important structures for motivated behavior and reward processing, their specific function during ongoing behavior is unknown. Using a movable tetrode array, we recorded LFPs and activity of neural ensembles in the ventral striatum of rats performing a reward-collection task. Rats were running along a triangle track and in each round collected one of three different types of rewards. The gamma power of LFPs on subsets of tetrodes was modulated by reward-site visits, discriminated between reward types, between baitedness of reward locations and was different before versus after arrival at a reward site. Many single units in ventral striatum phase-locked their discharge pattern to the gamma oscillations of the LFPs. Phase-locking occurred more often in reward-related than in reward-unrelated neurons and LFPs. A substantial number of simultaneously recorded LFPs correlated poorly with each other in terms of gamma rhythmicity, indicating that the expression of gamma activity was heterogeneous and regionally differentiated. The orchestration of LFPs and single-unit activity by way of gamma rhythmicity sheds light on the functional architecture of the ventral striatum and the temporal coordination of ventral striatal activity for modulating downstream areas and regulating synaptic plasticity.

Hippocampal-prefrontal theta coupling develops as mice become proficient in associative odorant discrimination learning

2021 ◽  
Author(s):  
Daniel Ramirez-Gordillo ◽  
Andrew A. Parra ◽  
K. Ulrich Bayer ◽  
Diego Restrepo
Keyword(s):  
Learning And Memory ◽  
Discrimination Learning ◽  
Gamma Oscillations ◽  
Oscillatory Activity ◽  
Dependent Protein Kinase ◽  
Dependent Protein ◽  
Theta Phase ◽  
Phase Amplitude ◽  
The Brain

Learning and memory requires coordinated activity between different regions of the brain. Here we studied the interaction between medial prefrontal cortex (mPFC) and hippocampal dorsal CA1 during associative odorant discrimination learning in the mouse. We found that as the animal learns to discriminate odorants in a go-no go task the coupling of high frequency neural oscillations to the phase of theta oscillations (phase-amplitude coupling or PAC) changes in a manner that results in divergence between rewarded and unrewarded odorant-elicited changes in the theta-phase referenced power (tPRP) for beta and gamma oscillations. In addition, in the proficient animal there was a decrease in the coordinated oscillatory activity between CA1 and mPFC in the presence of the unrewarded odorant. Furthermore, the changes in PAC resulted in a marked increase in the accuracy for decoding odorant identity from tPRP when the animal became proficient. Finally, we studied the role of Ca2+/calmodulin-dependent protein kinase II α (CaMKIIα), a protein involved in learning and memory, in oscillatory neural processing in this task. We find that the accuracy for decoding the odorant identity from tPRP decreases in CaMKIIα knockout mice and that this accuracy correlates with behavioral performance. These results implicate a role for PAC and CaMKIIα in olfactory go-no go associative learning in the hippocampal-prefrontal circuit.

scholarly journals Transformation of Independent Oscillatory Inputs into Temporally Precise Rate Codes

2016 ◽  
Author(s):  
David Tingley ◽  
Andrew A. Alexander ◽  
Laleh K. Quinn ◽  
Andrea A. Chiba ◽  
Douglas Nitz
Keyword(s):  
Field Potential ◽  
Spatial Location ◽  
Brain Regions ◽  
Synaptic Activity ◽  
Specific Rate ◽  
Attention Task ◽  
Potential Oscillations ◽  
Phase Precession ◽  
Theta Phase ◽  
Theta Phase Precession

AbstractComplex behaviors demand temporal coordination among functionally distinct brain regions. The basal forebrain’s afferent and efferent structure suggests a capacity for mediating such coordination. During performance of a selective attention task, synaptic activity in this region was dominated by four amplitude-independent oscillations temporally organized by the phase of the slowest, a theta rhythm. Further, oscillatory amplitudes were precisely organized by task epoch and a robust input/output transform, from synchronous synaptic activity to spiking rates of basal forebrain neurons, was identified. For many neurons, spiking was temporally organized as phase precessing sequences against theta band field potential oscillations. Remarkably, theta phase precession advanced in parallel to task progression, rather than absolute spatial location or time. Together, the findings reveal a process by which associative brain regions can integrate independent oscillatory inputs and transform them into sequence-specific, rate-coded outputs that are adaptive to the pace with which organisms interact with their environment.

scholarly journals Attention enhances category representations across the brain with strengthened residual correlations to ventral temporal cortex

2021 ◽  
Author(s):  
Arielle S Keller ◽  
Akshay V Jagadeesh ◽  
Lior Bugatus ◽  
Leanne M Williams ◽  
Kalanit Grill-Spector
Keyword(s):  
Selective Attention ◽  
Temporal Cortex ◽  
Relevant Information ◽  
Cortical Region ◽  
Visual Responses ◽  
Attention Task ◽  
Category Information ◽  
Ventral Temporal Cortex ◽  
Residual Correlations ◽  
The Brain

How does attention enhance neural representations of goal-relevant stimuli while suppressing representations of ignored stimuli across regions of the brain? While prior studies have shown that attention enhances visual responses, we lack a cohesive understanding of how selective attention modulates visual representations across the brain. Here, we used functional magnetic resonance imaging (fMRI) while participants performed a selective attention task on superimposed stimuli from multiple categories and used a data-driven approach to test how attention affects both decodability of category information and residual correlations (after regressing out stimulus-driven variance) with category-selective regions of ventral temporal cortex (VTC). Our data reveal three main findings. First, when two objects are simultaneously viewed, the category of the attended object can be decoded more readily than the category of the ignored object, with the greatest attentional enhancements observed in occipital and temporal lobes. Second, after accounting for the response to the stimulus, the correlation in the residual brain activity between a cortical region and a category-selective region of VTC was elevated when that region's preferred category was attended vs. ignored, and more so in the right occipital, parietal, and frontal cortices. Third, we found that the stronger the residual correlations between a given region of cortex and VTC, the better visual category information could be decoded from that region. These findings suggest that heightened residual correlations by selective attention may reflect the sharing of information between sensory regions and higher-order cortical regions to provide attentional enhancement of goal-relevant information.

scholarly journals The neural correlates of two forms of spiritual love: an EEG study

2016 ◽  
Author(s):  
E. S. Louise Faber
Keyword(s):  
Neural Activity ◽  
Emotional Experience ◽  
Gamma Oscillations ◽  
Neural Correlates ◽  
Spiritual Practices ◽  
Loving Kindness ◽  
Beta Power ◽  
Delta Activity ◽  
Gamma Power ◽  
The Brain

AbstractSpiritual practices are gaining an increasingly wider audience as a means to enhance positive affect in healthy individuals and to treat neurological disorders such as anxiety and depression. The current study aimed to examine the neural correlates of two different forms of love generated by spiritual practices using EEG; love generated during a loving kindness meditation performed by Buddhist meditators, and love generated during prayer, in a separate group of participants from a Christian-based faith. The loving kindness meditation was associated with significant increases in delta, alpha 1, alpha 2 and beta power compared to baseline, while prayer induced significant increases in power of alpha 1 and gamma oscillations, together with an increase in the gamma: theta ratio. An increase in delta activity occurred during the loving kindness meditation but not during prayer. In contrast increases in theta, alpha 1, alpha 2, beta and gamma power were observed when comparing both types of practice to baseline, suggesting that increases in these frequency bands are the neural correlates of spiritual love, independent of the type of practice used to attain the state of this type of love. These findings show that both spiritual love practices are associated with widespread changes in neural activity across the brain, in particular at frequency ranges that have been implicated in positive emotional experience, integration of distributed neural activity, and changes in short-term and longterm neural circuitry.

scholarly journals Astroglial Isopotentiality and Calcium-Associated Biomagnetic Field Effects on Cortical Neuronal Coupling

Cells ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 439
Author(s):  
Marcos Martinez-Banaclocha
Keyword(s):  
Current Knowledge ◽  
Critical Role ◽  
Brain Regions ◽  
Local Magnetic Field ◽  
Field Potentials ◽  
Coherent Integration ◽  
Cognitive Faculties ◽  
Synaptic Neurotransmission ◽  
New Research ◽  
The Brain

Synaptic neurotransmission is necessary but does not sufficiently explain superior cognitive faculties. Growing evidence has shown that neuron–astroglial chemical crosstalk plays a critical role in the processing of information, computation, and memory. In addition to chemical and electrical communication among neurons and between neurons and astrocytes, other nonsynaptic mechanisms called ephaptic interactions can contribute to the neuronal synchronization from different brain regions involved in the processing of information. New research on brain astrocytes has clearly shown that the membrane potential of these cells remains very stable among neighboring and distant astrocytes due to the marked bioelectric coupling between them through gap junctions. This finding raises the possibility that the neocortical astroglial network exerts a guiding template modulating the excitability and synchronization of trillions of neurons by astroglial Ca2+-associated bioelectromagnetic interactions. We propose that bioelectric and biomagnetic fields of the astroglial network equalize extracellular local field potentials (LFPs) and associated local magnetic field potentials (LMFPs) in the cortical layers of the brain areas involved in the processing of information, contributing to the adequate and coherent integration of external and internal signals. This article reviews the current knowledge of ephaptic interactions in the cerebral cortex and proposes that the isopotentiality of cortical astrocytes is a prerequisite for the maintenance of the bioelectromagnetic crosstalk between neurons and astrocytes in the neocortex.

scholarly journals A theta rhythm in macaque visual cortex and its attentional modulation

2018 ◽  
Vol 115 (24) ◽  
pp. E5614-E5623 ◽  
Author(s):  
Georgios Spyropoulos ◽  
Conrado Arturo Bosman ◽  
Pascal Fries
Keyword(s):  
Visual Attention ◽  
Language Processing ◽  
Theta Rhythm ◽  
Relevant Information ◽  
Sources Of Information ◽  
Attentional Modulation ◽  
Attention Task ◽  
Selective Visual Attention ◽  
Gamma Power ◽  
Theta Phase

Theta rhythms govern rodent sniffing and whisking, and human language processing. Human psychophysics suggests a role for theta also in visual attention. However, little is known about theta in visual areas and its attentional modulation. We used electrocorticography (ECoG) to record local field potentials (LFPs) simultaneously from areas V1, V2, V4, and TEO of two macaque monkeys performing a selective visual attention task. We found a ≈4-Hz theta rhythm within both the V1–V2 and the V4–TEO region, and theta synchronization between them, with a predominantly feedforward directed influence. ECoG coverage of large parts of these regions revealed a surprising spatial correspondence between theta and visually induced gamma. Furthermore, gamma power was modulated with theta phase. Selective attention to the respective visual stimulus strongly reduced these theta-rhythmic processes, leading to an unusually strong attention effect for V1. Microsaccades (MSs) were partly locked to theta. However, neuronal theta rhythms tended to be even more pronounced for epochs devoid of MSs. Thus, we find an MS-independent theta rhythm specific to visually driven parts of V1–V2, which rhythmically modulates local gamma and entrains V4–TEO, and which is strongly reduced by attention. We propose that the less theta-rhythmic and thereby more continuous processing of the attended stimulus serves the exploitation of this behaviorally most relevant information. The theta-rhythmic and thereby intermittent processing of the unattended stimulus likely reflects the ecologically important exploration of less relevant sources of information.

scholarly journals Learning improves decoding of odor identity with phase-referenced oscillations in the olfactory bulb

2019 ◽  
Author(s):  
Justin Losacco ◽  
Daniel Ramirez-Gordillo ◽  
Jesse Gilmer ◽  
Diego Restrepo
Keyword(s):  
Olfactory Bulb ◽  
Field Potential ◽  
Gamma Oscillations ◽  
Brain Regions ◽  
Spike Timing ◽  
Potential Oscillations ◽  
Theta Oscillation ◽  
Beta Power ◽  
Early Processing ◽  
Theta Phase

AbstractLocal field potential oscillations reflect temporally coordinated neuronal ensembles— coupling distant brain regions, gating processing windows, and providing a reference for spike timing-based codes. In phase amplitude coupling (PAC), the amplitude of the envelope of a faster oscillation is larger within a phase window of a slower carrier wave. Here, we characterized PAC, and the related theta phase-referenced high gamma and beta power (PRP), in the olfactory bulb of mice learning to discriminate odorants. PAC changes throughout learning, and odorant-elicited changes in PRP increase for rewarded and decrease for unrewarded odorants. Contextual odorant identity (is the odorant rewarded?) can be decoded from peak PRP in animals proficient in odorant discrimination, but not in naïve mice. As the animal learns to discriminate the odorants the dimensionality of PRP decreases. Therefore, modulation of phase-referenced chunking of information in the course of learning plays a role in early sensory processing in olfaction.SignificanceEarly processing of olfactory information takes place in circuits undergoing slow frequency theta oscillations generated by the interplay of olfactory input modulated by sniffing and centrifugal feedback from downstream brain areas. Studies in the hippocampus and cortex suggest that different information “chunks” are conveyed at different phases of the theta oscillation. Here we show that in the olfactory bulb, the first processing station in the olfactory system, the amplitude of high frequency gamma oscillations encodes for information on whether an odorant is rewarded when it is observed at the peak phase of the theta oscillation. Furthermore, encoding of information by the theta phase-referenced gamma oscillations becomes more accurate as the animal learns to differentiate two odorants.

scholarly journals A theta rhythm in macaque visual cortex and its attentional modulation

2017 ◽  
Author(s):  
Georgios Spyropoulos ◽  
Conrado A. Bosman ◽  
Pascal Fries
Keyword(s):  
Visual Attention ◽  
Language Processing ◽  
Theta Rhythm ◽  
Relevant Information ◽  
Sources Of Information ◽  
Attentional Modulation ◽  
Attention Task ◽  
Selective Visual Attention ◽  
Gamma Power ◽  
Theta Phase

AbstractTheta rhythms govern rodent sniffing and whisking, and human language processing. Human psychophysics suggests a role for theta also in visual attention. Yet, little is known about theta in visual areas and its attentional modulation. We used electrocorticography (ECoG) to record local field potentials (LFPs) simultaneously from areas V1, V2, V4 and TEO of two macaque monkeys performing a selective visual attention task. We found a ≈4 Hz theta rhythm within both the V1-V2 and the V4-TEO region, and theta synchronization between them, with a predominantly feedforward directed influence. ECoG coverage of large parts of these regions revealed a surprising spatial correspondence between theta and visually induced gamma. Furthermore, gamma power was modulated with theta phase. Selective attention to the respective visual stimulus strongly reduced these theta-rhythmic processes, leading to an unusually strong attention effect for V1. Microsaccades (MSs) were partly locked to theta. Yet, neuronal theta rhythms tended to be even more pronounced for epochs devoid of MSs. Thus, we find an MS-independent theta rhythm specific to visually driven parts of V1-V2, which rhythmically modulates local gamma and entrains V4-TEO, and which is strongly reduced by attention. We propose that the less theta-rhythmic and thereby more continuous processing of the attended stimulus serves the exploitation of this behaviorally most relevant information. The theta-rhythmic and thereby intermittent processing of the unattended stimulus likely reflects the ecologically important exploration of less relevant sources of information.

scholarly journals Odor induces characteristic time courses of theta, beta and gamma oscillations in human olfactory cortex

2021 ◽  
Author(s):  
Qiaohan Yang ◽  
Guangyu Zhou ◽  
Gregory Lane ◽  
Christina Zelano
Keyword(s):  
Temporal Dynamics ◽  
Piriform Cortex ◽  
Gamma Oscillations ◽  
Brain Regions ◽  
Olfactory Cortex ◽  
Odor Identification ◽  
Temporal Properties ◽  
Oscillatory Response ◽  
Theta Phase ◽  
Time Courses

Neuronal oscillations are fundamental to cognition, facilitating coordination and communication of information within and across brain regions. Studies on the spectral and temporal dynamics of oscillatory rhythms have contributed substantial insight to our understanding of mechanisms of human visual, auditory and somatosensory perception. However, these oscillations have been largely unexplored in the human olfactory system, where we lack basic understanding of fundamental spectrotemporal and functional properties. Determining if and how dynamic signatures of neural activity occur in human olfactory cortex is critical to understanding how we process odors. Here, we establish a characteristic oscillatory response to an odor in the human brain. Using direct electrical recordings from human piriform cortex, we identified three key odor-induced rhythms, in the theta (4-8Hz), beta (13-30Hz) and gamma (30-150Hz) frequency bands, each with distinct functional and temporal properties. While theta emerges and dissipates rapidly at the start of inhalation, beta and gamma emerge later, with beta persisting through exhalation, and gamma peaking around the transition between inhalation and exhalation. Beta and gamma amplitudes strongly predict odor identification ability, whereas theta does not. Theta phase modulates beta and gamma amplitudes during inhalation, only when odor is present. Our findings establish that smells elicit distinct neuronal rhythms in human olfactory cortex, which are dynamically interplayed over the course of a sniff. Our data further suggest a fundamental role for beta and gamma oscillations in human olfactory processing, and that their amplitudes--organized by theta phase--subserve odor identification in humans.

Sign in / Sign up

Export Citation Format

Share Document