scholarly journals Impaired Neural Synchrony in the Theta Frequency Range in Adolescents at Familial Risk for Schizophrenia

2011 ◽  
Vol 2 ◽  
Author(s):  
Franc C. L. Donkers ◽  
Shane R. Schwikert ◽  
Anna M. Evans ◽  
Katherine M. Cleary ◽  
Diana O. Perkins ◽  
...  
Keyword(s):  
Familial Risk ◽  
Neural Synchrony ◽  
Frequency Range ◽  
Theta Frequency

scholarly journals In your phase: neural phase synchronisation underlies visual imagery of faces

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Andrés Canales-Johnson ◽  
Renzo C. Lanfranco ◽  
Juan Pablo Morales ◽  
David Martínez-Pernía ◽  
Joaquín Valdés ◽  
...  
Keyword(s):  
Long Range ◽  
Visual Imagery ◽  
Brain Activity ◽  
Neural Connectivity ◽  
Frequency Range ◽  
Subjective Impression ◽  
Gamma Frequency ◽  
Gamma Range ◽  
Theta Frequency ◽  
Socially Relevant

AbstractMental imagery is the process through which we retrieve and recombine information from our memory to elicit the subjective impression of “seeing with the mind’s eye”. In the social domain, we imagine other individuals while recalling our encounters with them or modelling alternative social interactions in future. Many studies using imaging and neurophysiological techniques have shown several similarities in brain activity between visual imagery and visual perception, and have identified frontoparietal, occipital and temporal neural components of visual imagery. However, the neural connectivity between these regions during visual imagery of socially relevant stimuli has not been studied. Here we used electroencephalography to investigate neural connectivity and its dynamics between frontal, parietal, occipital and temporal electrodes during visual imagery of faces. We found that voluntary visual imagery of faces is associated with long-range phase synchronisation in the gamma frequency range between frontoparietal electrode pairs and between occipitoparietal electrode pairs. In contrast, no effect of imagery was observed in the connectivity between occipitotemporal electrode pairs. Gamma range synchronisation between occipitoparietal electrode pairs predicted subjective ratings of the contour definition of imagined faces. Furthermore, we found that visual imagery of faces is associated with an increase of short-range frontal synchronisation in the theta frequency range, which temporally preceded the long-range increase in the gamma synchronisation. We speculate that the local frontal synchrony in the theta frequency range might be associated with an effortful top-down mnemonic reactivation of faces. In contrast, the long-range connectivity in the gamma frequency range along the fronto-parieto-occipital axis might be related to the endogenous binding and subjective clarity of facial visual features.

Short- and Long-range Neural Synchrony in Grapheme–Color Synesthesia

2013 ◽  
Vol 25 (7) ◽  
pp. 1148-1162 ◽  
Author(s):  
Gregor Volberg ◽  
Anna Karmann ◽  
Stefanie Birkner ◽  
Mark W. Greenlee
Keyword(s):  
Long Range ◽  
Visual Processing ◽  
Short Range ◽  
Phase Locking ◽  
Brain Structures ◽  
Neural Synchrony ◽  
Beta Band ◽  
Color Processing ◽  
Processing Stream ◽  
Theta Frequency

Grapheme–color synesthesia is a perceptual phenomenon where single graphemes (e.g., the letter “E”) induce simultaneous sensations of colors (e.g., the color green) that were not objectively shown. Current models disagree as to whether the color sensations arise from increased short-range connectivity between anatomically adjacent grapheme- and color-processing brain structures or from decreased effectiveness of inhibitory long-range connections feeding back into visual cortex. We addressed this issue by examining neural synchrony obtained from EEG activity, in a sample of grapheme–color synesthetes that were presented with color-inducing versus non-color-inducing graphemes. For color-inducing graphemes, the results showed a decrease in the number of long-range couplings in the theta frequency band (4–7 Hz, 280–540 msec) and a concurrent increase of short-range phase-locking within lower beta band (13–20 Hz, 380–420 msec at occipital electrodes). Because the effects were both found in long-range synchrony and later within the visual processing stream, the results support the idea that reduced inhibition is an important factor for the emergence of synesthetic colors.

scholarly journals Endocannabinoids regulate mAChR-evoked theta rhythm IPSCs in hippocampus

2015 ◽  
Author(s):  
Ai-Hui Tang ◽  
Daniel A Nagode ◽  
Bradley E Alger
Keyword(s):  
Theta Rhythm ◽  
Cannabinoid Receptor ◽  
Spectral Power ◽  
Hippocampal Slices ◽  
Ionotropic Glutamate Receptors ◽  
Frequency Range ◽  
Neuronal Oscillations ◽  
Theta Frequency ◽  
Endogenous Cannabinoids

Exogenous cannabinoids can affect behaviorally relevant neuronal oscillations, but there is little evidence that endogenous cannabinoids (endocannabinoids, eCBs) can affect them, although it is unknown whether eCBs were generated during oscillations investigated in previous studies. In rat hippocampal slices, muscarinic receptor (mAChR) agonists stimulate the occurrence of persistent, rhythmic inhibitory post-synaptic currents (IPSC) activity and mobilize eCBs. We tested the hypothesis that mAChR-induced IPSCs would be modulated by concomitantly produced eCBs. With ionotropic glutamate receptors inhibited, mAChR agonist application triggered eCB-sensitive IPSCs that were enhanced in amplitude and frequency when a cannabinoid receptor antagonist was also present. There was also a highly significant increase in IPSC spectral power in the theta-frequency range. The data show that eCBs released by mAChRs modulate rhythmic IPSCs, and suggest that eCBs are candidate regulators of neuronal oscillations associated with eCB production in vivo.

scholarly journals Spike Frequency Adaptation Affects the Synchronization Properties of Networks of Cortical Oscillators

1998 ◽  
Vol 10 (4) ◽  
pp. 837-854 ◽  
Author(s):  
Sharon M. Crook ◽  
G. Bard Ermentrout ◽  
James M. Bower
Keyword(s):  
Pyramidal Cells ◽  
Rhythmic Activity ◽  
Spike Frequency ◽  
Spike Frequency Adaptation ◽  
Frequency Range ◽  
Cortical Dynamics ◽  
Gamma Frequency ◽  
Frequency Adaptation ◽  
Theta Frequency ◽  
Synchronous Behavior

Oscillations in many regions of the cortex have common temporal characteristics with dominant frequencies centered around the 40 Hz (gamma) frequency range and the 5–10 Hz (theta) frequency range. Experimental results also reveal spatially synchronous oscillations, which are stimulus dependent (Gray&Singer, 1987;Gray, König, Engel, & Singer, 1989; Engel, König, Kreiter, Schillen, & Singer, 1992). This rhythmic activity suggests that the coherence of neural populations is a crucial feature of cortical dynamics (Gray, 1994). Using both simulations and a theoretical coupled oscillator approach, we demonstrate that the spike frequency adaptation seen in many pyramidal cells plays a subtle but important role in the dynamics of cortical networks. Without adaptation, excitatory connections among model pyramidal cells are desynchronizing. However, the slow processes associated with adaptation encourage stable synchronous behavior.

scholarly journals In your phase: Neural phase synchronisation underlies visual imagery of faces

2019 ◽  
Author(s):  
Andrés Canales-Johnson ◽  
Renzo C. Lanfranco ◽  
Juan Pablo Morales ◽  
David Martínez-Pernía ◽  
Joaquín Valdés ◽  
...  
Keyword(s):  
Long Range ◽  
Visual Imagery ◽  
Brain Activity ◽  
Neural Connectivity ◽  
Frequency Range ◽  
Subjective Impression ◽  
Gamma Frequency ◽  
Gamma Range ◽  
Theta Frequency ◽  
Socially Relevant

ABSTRACTMental imagery is the process through which we retrieve and recombine information from our memory to elicit the subjective impression of “seeing with the mind’s eye”. In the social domain, we imagine other individuals while recalling our encounters with them or modelling alternative social interactions in future. Many studies using imaging and neurophysiological techniques have shown several similarities in brain activity between visual imagery and visual perception, and have identified frontoparietal, occipital and temporal neural components of visual imagery. However, the neural connectivity between these regions during visual imagery of socially relevant stimuli have not been studied. Here we used electroencephalography to investigate neural connectivity and its dynamics between frontal, parietal, occipital and temporal electrodes during visual imagery of faces. We found that voluntary visual imagery of faces is associated with long-range phase synchronisation in the gamma frequency range between frontoparietal electrode pairs and between occipitoparietal electrode pairs. In contrast, no effect of imagery was observed in the connectivity between occipitotemporal electrode pairs. Gamma range synchronisation between occipitoparietal electrode pairs predicted subjective ratings of the contour definition of imagined faces. Furthermore, we found that visual imagery of faces is associated with an increase of short-range frontal synchronisation in the theta frequency range, which temporally preceded the long-range increase in the gamma synchronisation. We speculate that the local frontal synchrony in the theta frequency range might be associated with an effortful top-down mnemonic reactivation of faces. In contrast, the long-range connectivity in the gamma frequency range along the fronto-parieto-occipital axis might be related to the endogenous binding and subjective clarity of facial visual features.

scholarly journals Brainstem network dynamics underlying the encoding of bladder information

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Anitha Manohar ◽  
Andre L Curtis ◽  
Stephen A Zderic ◽  
Rita J Valentino
Keyword(s):  
Prefrontal Cortex ◽  
Locus Coeruleus ◽  
Medial Prefrontal Cortex ◽  
Cortical Activation ◽  
Network Activity ◽  
Tonic Activity ◽  
Frequency Range ◽  
Attentional Processes ◽  
Theta Frequency ◽  
Temporal Offset

Urodynamic status must interact with arousal and attentional processes so that voiding occurs under appropriate conditions. To elucidate the central encoding of this visceral demand, multisite recordings were made within a putative pontine-cortical micturition circuit from the pontine micturition center (PMC), locus coeruleus (LC) and medial prefrontal cortex (mPFC) during cystometry in unanesthetized rats. PMC neurons had homogeneous firing patterns, characterized by tonic activity and phasic bursts that were temporally associated with distinct phases of the micturition cycle. LC and cortical activation became synchronized 20-30 s prior to micturition. During this pre-micturition interval, a theta oscillation developed in the LC, the mPFC desynchronized and LC-mPFC coherence increased in the theta frequency range. The temporal offset between the shift in LC-mPFC network activity and micturition may allow time to disengage from ongoing behaviors unrelated to micturition and initiate specific voiding behaviors so that micturition occurs in environmentally and socially appropriate conditions.

scholarly journals Sleep spectral power correlates of prospective memory maintenance

2021 ◽  
Vol 28 (9) ◽  
pp. 291-299
Author(s):  
Tony J. Cunningham ◽  
Ryan Bottary ◽  
Dan Denis ◽  
Jessica D. Payne
Keyword(s):  
Prospective Memory ◽  
Power Analysis ◽  
Slow Wave Sleep ◽  
Spectral Power ◽  
Time Of Day ◽  
Frequency Range ◽  
Ongoing Task ◽  
Healthy Young Adult ◽  
Adult Participants ◽  
Theta Frequency

Prospective memory involves setting an intention to act that is maintained over time and executed when appropriate. Slow wave sleep (SWS) has been implicated in maintaining prospective memories, although which SWS oscillations most benefit this memory type remains unclear. Here, we investigated SWS spectral power correlates of prospective memory. Healthy young adult participants completed three ongoing tasks in the morning or evening. They were then given the prospective memory instruction to remember to press “Q” when viewing the words “horse” or “table” when repeating the ongoing task after a 12-h delay including overnight, polysomnographically recorded sleep or continued daytime wakefulness. Spectral power analysis was performed on recorded sleep EEG. Two additional groups were tested in the morning or evening only, serving as time-of-day controls. Participants who slept demonstrated superior prospective memory compared with those who remained awake, an effect not attributable to time-of-day of testing. Contrary to prior work, prospective memory was negatively associated with SWS. Furthermore, significant increases in spectral power in the delta-theta frequency range (1.56 Hz–6.84 Hz) during SWS was observed in participants who failed to execute the prospective memory instructions. Although sleep benefits prospective memory maintenance, this benefit may be compromised if SWS is enriched with delta–theta activity.

scholarly journals Integrating pheromonal and spatial information in the amygdalo-hippocampal network

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
María Villafranca-Faus ◽  
Manuel Esteban Vila-Martín ◽  
Daniel Esteve ◽  
Esteban Merino ◽  
Anna Teruel-Sanchis ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Spatial Information ◽  
Dorsal Hippocampus ◽  
Territorial Behavior ◽  
Individual Identity ◽  
Frequency Range ◽  
Theta Frequency ◽  
Neural Substrate ◽  
Hippocampal Network ◽  
Pheromonal Information

AbstractVomeronasal information is critical in mice for territorial behavior. Consequently, learning the territorial spatial structure should incorporate the vomeronasal signals indicating individual identity into the hippocampal cognitive map. In this work we show in mice that navigating a virtual environment induces synchronic activity, with causality in both directionalities, between the vomeronasal amygdala and the dorsal CA1 of the hippocampus in the theta frequency range. The detection of urine stimuli induces synaptic plasticity in the vomeronasal pathway and the dorsal hippocampus, even in animals with experimentally induced anosmia. In the dorsal hippocampus, this plasticity is associated with the overexpression of pAKT and pGSK3β. An amygdalo-entorhino-hippocampal circuit likely underlies this effect of pheromonal information on hippocampal learning. This circuit likely constitutes the neural substrate of territorial behavior in mice, and it allows the integration of social and spatial information.

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