scholarly journals Focal gamma activity in frontal control regions revealed using intraoperative electrocorticography

2021 ◽  
Author(s):  
Moataz Assem ◽  
Michael Gavin Hart ◽  
Pedro Coelho ◽  
Rafael Romero Garcia ◽  
Alexa Mcdonald ◽  
...  
Keyword(s):  
Cognitive Control ◽  
Frontal Cortex ◽  
Gamma Activity ◽  
Difficulty Level ◽  
Supporting Evidence ◽  
Indirect Measure ◽  
Gamma Range ◽  
Gamma Power ◽  
Glioma Resection ◽  
Control Regions

How the frontal cortex is anatomically and functionally organized to control cognition remains puzzling. Numerous non-invasive brain imaging studies relate cognitive control to a localized set of frontal regions, part of a wider fronto-parietal network (FPN), that show increases in functional MRI (fMRI) signal during the performance of multiple cognitively demanding tasks. Lesions implicating frontal control regions lead to disorganized behaviour. However, the fMRI BOLD signal is an indirect measure of neuronal activity and represents evidence from a single modality. This has led to limited clinical translation of fMRI findings e.g. to guide the surgical resection of brain tumours. Here we sought supporting evidence for lateral frontal control regions using electrocorticography (ECoG). We recorded electrophysiological activity from electrodes placed on the lateral frontal cortex in patients undergoing awake craniotomy for glioma resection. During surgery, patients performed two verbal executive-related counting tasks with a difficulty level manipulation, closely adapting difficulty manipulations in fMRI studies of cognitive control. We performed spectral analysis focusing on the gamma range (30-250 Hz) due to mounting evidence of its value as an index of local cortical processing. Comparing hard versus easy demands revealed circumscribed frontal regions with power increases in the gamma range. This contrasted with spatially distributed power decreases in the beta range (12-30 Hz). Further, electrodes showing significant gamma power increases were more likely to occur within a canonical fMRI-defined FPN and showed stronger gamma power increases compared to electrodes outside the FPN, even at the single patient level. Reinforcing the need for careful task manipulation, an easy versus baseline comparison, which includes factors such as speech output, produced gamma changes over a wider area. Thus, using similar task difficulty manipulations, ECoG and fMRI signals converged on delineating lateral frontal control regions. These findings open the door for extending clinical functional mapping to the domain of cognitive control during awake neurosurgery.

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.

scholarly journals Sensorimotor cortical-subthalamic network dynamics during force generation

2018 ◽  
Author(s):  
Ahmad Alhourani ◽  
Anna Korzeniewska ◽  
Thomas A. Wozny ◽  
Witold J. Lipski ◽  
Efstathios D. Kondylis ◽  
...  
Keyword(s):  
Somatosensory Cortex ◽  
Grip Force ◽  
Phase Locking ◽  
Motor Planning ◽  
Gamma Activity ◽  
Dynamic Scaling ◽  
Beta Activity ◽  
Cortical Dynamics ◽  
Gamma Range ◽  
Gamma Power

AbstractThe subthalamic nucleus (STN) is proposed to participate in pausing, or alternately, in dynamic scaling of behavioral responses, roles that have conflicting implications for understanding STN function in the context of deep brain stimulation (DBS) therapy. To examine the nature of event-related STN activity and subthalamic-cortical dynamics, we performed primary motor and somatosensory electrocorticography while subjects (n=10) performed a grip force task during DBS implantation surgery. The results provide the first evidence from humans that STN gamma activity can predict activity in the cortex both prior to and during movement, consistent with the idea that the STN participates in both motor planning and execution. We observed that STN activity appeared to facilitate movement: while both movement onset and termination both coincided with STN-cortical phase-locking, narrow-band gamma power was positively correlated with grip force, and event-related causality measures demonstrated that STN gamma activity predicted cortical gamma activity during movement. STN participation in somatosensory integration also was demonstrated by casual analysis. Information flow from the STN to somatosensory cortex was observed for both beta and gamma range frequencies, specific to particular movement periods and kinematics. Interactions in beta activity between the STN and somatosensory cortex, rather than motor cortex, predicted PD symptom severity. Thus, the STN contributes to multiple aspects of sensorimotor behavior dynamically across time.

A Preliminary Study of the Association Among Metacognition and Resting State EEG in Schizophrenia

2016 ◽  
Vol 30 (2) ◽  
pp. 47-54 ◽  
Author(s):  
Jenifer L. Vohs ◽  
Bethany L. Leonhardt ◽  
Michael M. Francis ◽  
Daniel Westfall ◽  
Josselyn Howell ◽  
...  
Keyword(s):  
Resting State ◽  
Brain Activity ◽  
Gamma Activity ◽  
Multiple Perspectives ◽  
Behavioral Correlates ◽  
Form Complex ◽  
Gamma Frequency ◽  
Gamma Range ◽  
The World ◽  
Gamma Power

Abstract. Metacognition refers to a spectrum of activities that range from the consideration of discrete mental experiences, such as a specific thought or emotion, to the synthesis of discrete perceptions into integrated representations of the self and others as unique agents in the world. Metacognitive deficits have been observed in schizophrenia and linked with a number of behavioral correlates and outcomes. Less is known however about the neural systems associated with such processes. Establishing the link between brain activity and metacognition therefore is an essential next step. Resting state electroencephalography (EEG) provides one possible avenue for investigating this link. EEG studies in schizophrenia suggest that the gamma frequency range may have functional significance and be related to the disturbed information processing often observed in the disorder. In the present investigation, we assessed metacognition among 20 individuals with prolonged schizophrenia using the Metacognition Assessment Scale Abbreviated, who also participated in resting state EEG recording. We hypothesized that gamma activity would be associated with those domains of metacognition that require the most integration to perform, Decentration and Mastery. We then examined the association among gamma power and each metacognitive domain. Additional exploratory analyses were conducted across a spectrum of EEG activity. We found that increased gamma activity at rest was linked with decreased decentration. This suggests that hyperactivity in the gamma range may index disrupted processing and integration, and ultimately the metacognitive processes needed to form complex ideas about oneself and others and to see the world from multiple perspectives. This link provides additional evidence of how the biological roots of schizophrenia may culminate in a disrupted life.

scholarly journals Intraoperative mapping of cognitive control regions in the frontal cortex using electrocorticography

IBRO Reports ◽  
2019 ◽  
Vol 6 ◽  
pp. S446
Author(s):  
Moataz Assem ◽  
Mike Hart ◽  
Rafael Romero-Garcia ◽  
Jessica Ingham ◽  
Alexa Mcdonald ◽  
...  
Keyword(s):  
Cognitive Control ◽  
Frontal Cortex ◽  
Intraoperative Mapping ◽  
Control Regions

Reading in children with drug‐resistant epilepsy was related to functional connectivity in cognitive control regions

2020 ◽  
Vol 109 (10) ◽  
pp. 2105-2111
Author(s):  
Dror Kraus ◽  
Jennifer Vannest ◽  
Ravindra Arya ◽  
John S. Hutton ◽  
James L. Leach ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Cognitive Control ◽  
Drug Resistant ◽  
Drug Resistant Epilepsy ◽  
Control Regions

scholarly journals Pubertal Testosterone Tracks the Developmental Trajectory of Neural Oscillatory Activity Serving Visuospatial Processing

2020 ◽  
Vol 30 (11) ◽  
pp. 5960-5971 ◽  
Author(s):  
Madison H Fung ◽  
Brittany K Taylor ◽  
Michaela R Frenzel ◽  
Jacob A Eastman ◽  
Yu-Ping Wang ◽  
...  
Keyword(s):  
Developmental Trajectory ◽  
Gamma Activity ◽  
Oscillatory Activity ◽  
Childhood And Adolescence ◽  
Oscillatory Dynamics ◽  
Gamma Range ◽  
Visuospatial Perception ◽  
Hormonal Fluctuations ◽  
Visuospatial Processing ◽  
The Right

Abstract Puberty is a period of substantial hormonal fluctuations that induce dramatic physical, neurological, and behavioral changes. Previous research has demonstrated that pubertal hormones modulate cortical development, as well as sex- and age-specific patterns of cognitive development during childhood and adolescence. However, the influence of pubertal hormones on the brain’s functional development, specifically neural oscillatory dynamics, has yet to be fully examined. Thus, in the current study, we used magnetoencephalography to investigate the oscillatory dynamics serving visuospatial perception and attention, and testosterone levels and chronological age as measures of development. Within a sample of typically developing youth, age was associated with changes in alpha, theta, and gamma oscillatory activity. Novel testosterone-by-sex interactions in the gamma range were identified in critical areas of the visual and attention networks. Females had increased gamma activity with increasing testosterone in the right temporal-parietal junction and occipital cortices, while males showed increased gamma activity in the right insula with increasing testosterone. These findings reveal robust developmental alterations in the oscillatory dynamics serving visuospatial processing during childhood and adolescence and provide novel insight into the hormonal basis of sexually dimorphic patterns of functional brain development during the pubertal transition that is at least partially mediated by endogenous testosterone.

A NEUROBIOLOGICAL THEORY OF MEANING IN PERCEPTION PART IV: MULTICORTICAL PATTERNS OF AMPLITUDE MODULATION IN GAMMA EEG

2003 ◽  
Vol 13 (10) ◽  
pp. 2857-2866 ◽  
Author(s):  
WALTER J. FREEMAN ◽  
BRIAN C. BURKE
Keyword(s):  
Amplitude Modulation ◽  
Euclidean Distance ◽  
Time Windows ◽  
Gamma Activity ◽  
Moving Window ◽  
Conditioned Stimuli ◽  
Root Mean Square Amplitude ◽  
Gamma Range ◽  
Sensory Area ◽  
Multisensory Convergence

The aim of this study is to find spatial patterns of EEG amplitude in the gamma range of the EEGs from multiple sensory and limbic areas that demonstrate multisensory convergence and integration. 64 electrodes spread in small arrays were fixed on or in the olfactory, visual, auditory, somatomotor and entorhinal areas of cats and rabbits. The subjects were trained to discriminate 2 visual and then 2 auditory conditioned stimuli, one reinforced (CS+), the other not (CS-). A moving window was applied to the 6-s records from 20 trials of each CS including a 3-s prestimulus control (CS0). The root mean square amplitude was calculated for each signal in the gamma range, so each window gave a point in 64-space. EEG patterns from the CS+, CS- and CS0 conditions gave 3 clusters of points in 64-space. The Euclidean distance of each point to the nearest center of gravity of a cluster served for classification and estimation of the probability of correct classification. The results showed that the gamma activity (35–60 Hz in cats, 20–80 Hz in rabbits) in all five areas formed global patterns of amplitude modulation (AM) in time windows lasting ~100–200 ms and recurring at 2–4 Hz, which were correctly classified above chance levels (p<0.01). All areas contributed information to the AM patterns that served to classify the EEG epochs in the windows with respect to the conditioned stimuli. In conclusion, multisensory integration took place over the greater part of the hemisphere, despite lack of phase coherence among the gamma waves. The integration occurred rapidly enough that, within 300 ms of CS onset, activity in every sensory area was modified by what took place in every other sensory area.

scholarly journals Deficient auditory gamma-BOLD coupling in schizophrenia is related to sensory gating deficits

2021 ◽  
Author(s):  
Michael Jacob ◽  
Kaia Sargent ◽  
Brian Roach ◽  
Elhum Shamshiri ◽  
Daniel Mathalon ◽  
...  
Keyword(s):  
Resting State ◽  
Sensory Gating ◽  
Psychotic Symptoms ◽  
Gamma Range ◽  
Syndrome Scale ◽  
Regional Hemodynamics ◽  
Gamma Power ◽  
Eyes Open ◽  
Pulse Sound ◽  
Negative Syndrome

Background: Schizophrenia is associated with aberrant gamma band power, hypothesized to reflect imbalance in the excitation-inhibition (E/I) ratio and undermine neural signal efficiency. Relationships between resting-state gamma, E/I balance, and regional hemodynamics from the fMRI BOLD signal are unknown. Methods: We recorded simultaneous EEG-fMRI at rest, with eyes open, in people with schizophrenia (n= 57) and people without a psychiatric diagnosis (n= 46) and identified gamma and aperiodic EEG parameters associated with E/I balance. Measures from all EEG channels were entered into a whole-brain, parametric modulation analysis followed by statistical correction for multiple comparisons. Sensory gating was assessed using the Sensory Gating Inventory, and psychotic symptoms were assessed using the Positive and Negative Syndrome Scale. Results: Across groups, gamma power modestly predicts a steeper aperiodic slope (greater inhibition), without group differences in either gamma power or aperiodic slope. In schizophrenia, gamma-BOLD coupling was reduced in bilateral auditory regions of the superior temporal gyri and inversely correlated with sensory gating deficits and symptom severity. Analysis of the spectral features of scanner sounds revealed distinct peaks in the gamma range, reflecting a rapidly repeating scanner pulse sound present throughout the resting state recording. Conclusion: Regional hemodynamic support for putative inhibitory and excitatory contributions to resting EEG are aberrant in SZ. Deficient gamma coupling to auditory BOLD may reflect impaired gating of fMRI-scanner sound.

Forebrain Acetylcholine Modulates Isoflurane and Ketamine Anesthesia in Adult Mice

2021 ◽  
Vol 134 (4) ◽  
pp. 588-606 ◽  
Author(s):  
L. Stan Leung ◽  
Liangwei Chu ◽  
Marco A. M. Prado ◽  
Vania F. Prado
Keyword(s):  
Interaction Effect ◽  
Gamma Activity ◽  
Wild Type ◽  
Male Adult ◽  
Adult Mice ◽  
Loss Of Righting Reflex ◽  
High Gamma ◽  
Ketamine Anesthesia ◽  
Gamma Power ◽  
Righting Reflex

Background Cholinergic drugs are known to modulate general anesthesia, but anesthesia responses in acetylcholine-deficient mice have not been studied. It was hypothesized that mice with genetic deficiency of forebrain acetylcholine show increased anesthetic sensitivity to isoflurane and ketamine and decreased gamma-frequency brain activity. Methods Male adult mice with heterozygous knockdown of vesicular acetylcholine transporter in the brain or homozygous knockout of the transporter in the basal forebrain were compared with wild-type mice. Hippocampal and frontal cortical electrographic activity and righting reflex were studied in response to isoflurane and ketamine doses. Results The loss-of-righting-reflex dose for isoflurane was lower in knockout (mean ± SD, 0.76 ± 0.08%, n = 18, P = 0.005) but not knockdown (0.78 ± 0.07%, n = 24, P = 0.021), as compared to wild-type mice (0.83 ± 0.07%, n = 23), using a significance criterion of P = 0.017 for three planned comparisons. Loss-of-righting-reflex dose for ketamine was lower in knockout (144 ± 39 mg/kg, n = 14, P = 0.006) but not knockdown (162 ± 32 mg/kg, n = 20, P = 0.602) as compared to wild-type mice (168 ± 24 mg/kg, n = 21). Hippocampal high-gamma (63 to 100 Hz) power after isoflurane was significantly lower in knockout and knockdown mice compared to wild-type mice (isoflurane-dose and mouse-group interaction effect, F[8,56] = 2.87, P = 0.010; n = 5 to 6 mice per group). Hippocampal high-gamma power after ketamine was significantly lower in both knockout and knockdown mice when compared to wild-type mice (interaction effect F[2,13] = 6.06, P = 0.014). The change in frontal cortical gamma power with isoflurane or ketamine was not statistically different among knockout, knockdown, and wild-type mice. Conclusions These findings suggest that forebrain cholinergic neurons modulate behavioral sensitivity and hippocampal gamma activity during isoflurane and ketamine anesthesia. Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New

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