scholarly journals Thalamocortical transmission of visual information in awake mice involves phase synchronization and spike synchrony at high gamma frequencies

2017 ◽  
Author(s):  
Samuel S. McAfee ◽  
Yu Liu ◽  
Mukesh Dhamala ◽  
Detlef H. Heck
Keyword(s):  
Sensory Processing ◽  
Spike Activity ◽  
Visual Information ◽  
Gamma Oscillations ◽  
High Contrast ◽  
Beta Oscillations ◽  
Gamma Frequency ◽  
Gamma Range ◽  
High Gamma ◽  
The Brain

Abstract:Synchronization of neuronal spike activity is thought to play a key role in the transmission of information for sensory processing in the brain, and this synchronization is influenced by oscillatory population activity occurring in multiple frequency ranges at multiple stages of sensory pathways. In the neocortex, gamma frequency oscillations appear to play an important role in synchronizing neuronal ensembles and allowing for selective communication between regions, yet relatively little is known about whether gamma oscillations facilitate transmission of sensory information from thalamus to cortex. Here, we investigate the role of gamma oscillations in promoting synchronous spike activity between the visual thalamus (dLGN) and primary visual cortex (V1) in awake mice, a model sensory system with prominent gamma oscillations that are modulated by visual input. We demonstrate that transmission of visual information to cortex involves phase-synchronized oscillations in the high gamma range (50-90Hz), with concomitant millisecond-scale synchronization of thalamic and cortical spike activity. Transition from a full-field gray image to a high-contrast checkerboard image caused gamma activity to rapidly increase in amplitude, frequency, and bandwidth, yet the gamma oscillations in dLGN and V1 maintained a consistent phase relationship. High contrast stimulation also caused an increase in amplitude of oscillations in the beta and low gamma range, but those were not associated with synchronous thalamic activity. These results indicate a role for high gamma oscillations in mediating the functional connectivity between thalamic and cortical neurons in the visual pathway, a similar role to beta oscillations in primates.Significance statement:The mechanisms by which neurons selectively communicate are essential to our understanding of how the brain processes information. Abundant evidence suggests that cortical sensory processing involves the synchronization of high frequency electric field oscillations known as gamma oscillations, which allow groups of neurons to synchronize their spike activity in order to collaboratively process sensory input. Here, we show that oscillations and spikes in the visual thalamocortical pathway of the mouse exhibit synchrony across a broad high gamma frequency range (50-90Hz), suggesting these oscillations play an important role in the relay of visual information to the cortex. This is substantially different from oscillations observed in monkeys, in which gamma is absent in thalamus and beta oscillations support thalamocortical relay.

scholarly journals Granule cell excitability regulates gamma and beta oscillations in a model of the olfactory bulb dendrodendritic microcircuit

2016 ◽  
Vol 116 (2) ◽  
pp. 522-539 ◽  
Author(s):  
Bolesław L. Osinski ◽  
Leslie M. Kay
Keyword(s):  
Olfactory Bulb ◽  
Granule Cells ◽  
Field Potential ◽  
Gamma Oscillations ◽  
Causal Link ◽  
Beta Oscillations ◽  
Gamma Frequency ◽  
Voltage Dependent ◽  
Nmda Channels ◽  
Beta Frequency

Odors evoke gamma (40–100 Hz) and beta (20–30 Hz) oscillations in the local field potential (LFP) of the mammalian olfactory bulb (OB). Gamma (and possibly beta) oscillations arise from interactions in the dendrodendritic microcircuit between excitatory mitral cells (MCs) and inhibitory granule cells (GCs). When cortical descending inputs to the OB are blocked, beta oscillations are extinguished whereas gamma oscillations become larger. Much of this centrifugal input targets inhibitory interneurons in the GC layer and regulates the excitability of GCs, which suggests a causal link between the emergence of beta oscillations and GC excitability. We investigate the effect that GC excitability has on network oscillations in a computational model of the MC-GC dendrodendritic network with Ca2+-dependent graded inhibition. Results from our model suggest that when GC excitability is low, the graded inhibitory current mediated by NMDA channels and voltage-dependent Ca2+ channels (VDCCs) is also low, allowing MC populations to fire in the gamma frequency range. When GC excitability is increased, the activation of NMDA receptors and other VDCCs is also increased, allowing the slow decay time constants of these channels to sustain beta-frequency oscillations. Our model argues that Ca2+ flow through VDCCs alone could sustain beta oscillations and that the switch between gamma and beta oscillations can be triggered by an increase in the excitability state of a subpopulation of GCs.

Visual Grouping and the Focusing of Attention Induce Gamma-band Oscillations at Different Frequencies in Human Magnetoencephalogram Signals

2006 ◽  
Vol 18 (11) ◽  
pp. 1850-1862 ◽  
Author(s):  
Juan R. Vidal ◽  
Maximilien Chaumon ◽  
J. Kevin O'Regan ◽  
Catherine Tallon-Baudry
Keyword(s):  
Short Term Memory ◽  
Implementation Process ◽  
Visual Display ◽  
Gamma Oscillations ◽  
Gamma Band ◽  
Visual Grouping ◽  
Gamma Range ◽  
High Gamma ◽  
The One ◽  
Attentional Filter

Neural oscillatory synchrony could implement grouping processes, act as an attentional filter, or foster the storage of information in short-term memory. Do these findings indicate that oscillatory synchrony is an unspecific epiphenomenon occurring in any demanding task, or that oscillatory synchrony is a fundamental mechanism involved whenever neural cooperation is requested? If the latter hypothesis is true, then oscillatory synchrony should be specific, with distinct visual processes eliciting different types of oscillations. We recorded magnetoencephalogram (MEG) signals while manipulating the grouping properties of a visual display on the one hand, and the focusing of attention to memorize part of this display on the other hand. Grouping-related gamma oscillations were present in all conditions but modulated by the grouping properties of the stimulus (one or two groups) in the high gamma-band (70–120 Hz) at central occipital locations. Attention-related gamma oscillations appeared as an additional component whenever attentional focusing was requested in the low gamma-band (44–66 Hz) at parietal locations. Our results thus reveal the existence of a functional specialization in the gamma range, with grouping-related oscillations showing up at higher frequencies than attention-related oscillations. The pattern of oscillatory synchrony is thus specific of the visual process it is associated with. Our results further suggest that both grouping processes and focused attention rely on a common implementation process, namely, gamma-band oscillatory synchrony, a finding that could account for the fact that coherent percepts are more likely to catch attention than incoherent ones.

scholarly journals Dysbindin-1 regulates mitochondrial fission and gamma oscillations

2021 ◽  
Author(s):  
Jun Zhao ◽  
Huiwen Zhu ◽  
Kaizheng Duan ◽  
Ronald S. Petralia ◽  
Ya-Xian Wang ◽  
...  
Keyword(s):  
Mitochondrial Fission ◽  
Gamma Oscillations ◽  
Gamma Frequency ◽  
Neural Activities ◽  
Induced Fission ◽  
Dynamic Structures ◽  
Energy Challenge ◽  
Great Energy ◽  
The Brain

AbstractMitochondria are cellular ATP generators. They are dynamic structures undergoing fission and fusion. While much is known about the mitochondrial fission machinery, the mechanism of initiating fission and the significance of fission to neurophysiology are largely unclear. Gamma oscillations are synchronized neural activities that impose a great energy challenge to synapses. The cellular mechanism of fueling gamma oscillations has yet to be defined. Here, we show that dysbindin-1, a protein decreased in the brain of individuals with schizophrenia, is required for neural activity-induced fission by promoting Drp1 oligomerization. This process is engaged by gamma-frequency activities and in turn, supports gamma oscillations. Gamma oscillations and novel object recognition are impaired in dysbindin-1 null mice. These defects can be ameliorated by increasing mitochondrial fission. These findings identify a molecular mechanism for activity-induced mitochondrial fission, a role of mitochondrial fission in gamma oscillations, and mitochondrial fission as a potential target for improving cognitive functions.

scholarly journals Cortical beta oscillations reflect the contextual gating of visual action feedback

2020 ◽  
Author(s):  
Jakub Limanowski ◽  
Vladimir Litvak ◽  
Karl Friston
Keyword(s):  
Visual Information ◽  
Sensorimotor Integration ◽  
Beta Oscillations ◽  
Precision Control ◽  
Sensory Data ◽  
Causal Modelling ◽  
Beta Power ◽  
Current Context ◽  
The Brain ◽  
Real Hand

AbstractIn sensorimotor integration, the brain needs to decide how its predictions should accommodate novel evidence by ‘gating’ sensory data depending on the current context. Here, we examined the oscillatory correlates of this process using magnetoencephalography (MEG). We used virtual reality to decouple visual (virtual) and proprioceptive (real) hand postures during a task requiring matching either modality’s grasping movements to a target oscillation. Thus, we rendered visual information either task-relevant or a (to-be-ignored) distractor. Under visuo-proprioceptive incongruence, occipital beta power decreased relative to congruence when vision was task-relevant but increased when it had to be ignored. Dynamic causal modelling (DCM) revealed that this interaction was best explained by diametrical, task-dependent changes in visual gain. These results suggest a crucial role for beta oscillations in sensorimotor integration; particularly, in the contextual gating (i.e., gain or precision control) of visual vs proprioceptive action feedback, depending on concurrent behavioral demands.

scholarly journals Distinct Narrow and Broadband Gamma Responses in Human Visual Cortex

2019 ◽  
Author(s):  
Eleonora Bartoli ◽  
William Bosking ◽  
Ye Li ◽  
Michael S. Beauchamp ◽  
Daniel Yoshor ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Critical Role ◽  
Visual Stimuli ◽  
Field Potential ◽  
Gamma Oscillations ◽  
Systematic Change ◽  
Human Visual Cortex ◽  
Gamma Range ◽  
High Gamma ◽  
Differential Properties

AbstractHigh frequency activity (> 30 Hz) in the neocortical local field potential, typically referred to as the ‘gamma’ range, is thought to have a critical role in visual perception and cognition more broadly. Historically, animal studies recording from visual cortex documented clear narrowband gamma oscillations (NBG; ∼20-60 Hz) in response to visual stimuli. However, invasive measurements from human neocortex have highlighted a different broadband or ‘high’ gamma response (BBG; ∼70-150+ Hz). Growing evidence suggests these two forms of gamma response are distinct, but often conceptually or analytically conflated as the same ‘gamma’ response. Furthermore, recent debate has highlighted that both the occurrence and spectral properties of gamma band activity in visual cortex appears to be dependent on the attributes and class of presented visual stimuli. Using high-density intracranial recordings from human visual cortex, we integrate and extend these findings, dissociating the spectral, temporal and functional properties of NBG and BBG activity. We report results from two experiments, manipulating visual stimulus attributes (contrast-varying gratings) and class (object categories) dissecting the differential properties of NBG and BBG responses. NBG oscillations were only reliably recorded for grating stimuli, while their peak frequency varied with contrast level. Whereas BBG activity was observed in response to all stimulus classes tested, with no systematic change in its spectral features. Temporally, induced NBG was sustained throughout stimulus presentation, in opposition to a more transient response for the BBG. These findings challenge the ubiquity of ‘gamma’ activity in visual cortex, by clearly dissociating oscillatory and broadband effects.Significance StatementNeocortical narrowband gamma oscillations (∼20-60 Hz) have been implicated in vision and cognition as a mechanism for synchronizing brain regions. Efforts to study this phenomenon have revealed an additional ‘high-gamma’ range response (∼70-150+ Hz), which is broadband and non-oscillatory. These different gamma range activities are often conflated in support of the same functional role. Using invasive recordings from human visual cortex, we show that narrow and broadband gamma can be dissociated by spectral, temporal and functional response properties. While broadband gamma responses were more transient to the presentation of all stimuli, narrowband gamma responses were sustained and only occurred reliably to grating stimuli. These differences have important implications for the study, analysis and interpretation of neocortical gamma range activity.

COGNITIVE FUNCTION ASSESSMENT IN YOUNG ADULT USING TRAIL MAKING AND STROOP TESTS

2016 ◽  
Vol 78 (7-5) ◽  
Author(s):  
Syazreen Hashim ◽  
Norlaili Mat Safri ◽  
Mohd Afzan Othman ◽  
Nor Aini Zakaria
Keyword(s):  
Cognitive Function ◽  
Power Spectrum ◽  
Brain Activity ◽  
Brain Regions ◽  
Frontal Area ◽  
Gamma Frequency ◽  
High Gamma ◽  
Trail Making ◽  
Scalp Location ◽  
The Brain

Cortical network between brain regions is one of the topics that being investigated by brain researchers. Methods that are used to investigate brain developments of cognitive function include Partial Directed Coherence (PDC) and the power spectrum of the brain activity. The purposes of this study were to determine the cortico-cortical functional connectivity between brain regions using PDC and to investigate the power spectrum of brain activity while performing cognitive function assessments. Twenty healthy young adults, age between 20 to 30 years old, were asked to perform two tasks/tests; Trail Making Test (TMTA-alphabet, TMTA-number, TMTB-mixed alphabets and numerical) and Stroop Task. An electroencephalogram (EEG) machine was used to record the brain signals, and the data were analyzed using PDC and Fast Fourier Transform (FFT).Our findings showed that not only frontal area but temporal and occipital area also generates information and the information was sent to various scalp location. Theta frequency was significantly increased at frontal area while gamma and high-gamma frequency bands were significantly increased at centro-parieto-occipito-temporal regions. All of these areas are associated with cognitive function doing specific task.

scholarly journals Cross-Modal Effect of Presenting Visual and Force Feedback That Create the Illusion of Stair-Climbing

2021 ◽  
Vol 11 (7) ◽  
pp. 2987
Author(s):  
Takumi Okumura ◽  
Yuichi Kurita
Keyword(s):  
Visual Information ◽  
Force Feedback ◽  
Activity Level ◽  
Experimental Results ◽  
Stair Climbing ◽  
Mirror Therapy ◽  
Visual Condition ◽  
Stroke Patients ◽  
Head Mount Display ◽  
The Brain

Image therapy, which creates illusions with a mirror and a head mount display, assists movement relearning in stroke patients. Mirror therapy presents the movement of the unaffected limb in a mirror, creating the illusion of movement of the affected limb. As the visual information of images cannot create a fully immersive experience, we propose a cross-modal strategy that supplements the image with sensual information. By interacting with the stimuli received from multiple sensory organs, the brain complements missing senses, and the patient experiences a different sense of motion. Our system generates the sense of stair-climbing in a subject walking on a level floor. The force sensation is presented by a pneumatic gel muscle (PGM). Based on motion analysis in a human lower-limb model and the characteristics of the force exerted by the PGM, we set the appropriate air pressure of the PGM. The effectiveness of the proposed system was evaluated by surface electromyography and a questionnaire. The experimental results showed that by synchronizing the force sensation with visual information, we could match the motor and perceived sensations at the muscle-activity level, enhancing the sense of stair-climbing. The experimental results showed that the visual condition significantly improved the illusion intensity during stair-climbing.

Sign in / Sign up

Export Citation Format

Share Document