scholarly journals Spatiotemporal evolution of focal epileptiform activity from surface and laminar field recordings in cat neocortex

2018 ◽  
Vol 119 (6) ◽  
pp. 2068-2081 ◽  
Author(s):  
Hank Bink ◽  
Madineh Sedigh-Sarvestani ◽  
Ivan Fernandez-Lamo ◽  
Lohith Kini ◽  
Hoameng Ung ◽  
...  
Keyword(s):  
Visual Cortex ◽  
High Resolution ◽  
Local Field ◽  
Epileptiform Activity ◽  
Local Field Potentials ◽  
Great Promise ◽  
Epileptic Focus ◽  
Field Potentials ◽  
Cortical Layers ◽  
Spatial Spread

New devices that use targeted electrical stimulation to treat refractory localization-related epilepsy have shown great promise, although it is not well known which targets most effectively prevent the initiation and spread of seizures. To better understand how the brain transitions from healthy to seizing on a local scale, we induced focal epileptiform activity in the visual cortex of five anesthetized cats with local application of the GABAA blocker picrotoxin while simultaneously recording local field potentials on a high-resolution electrocorticography array and laminar depth probes. Epileptiform activity appeared in the form of isolated events, revealing a consistent temporal pattern of ictogenesis across animals with interictal events consistently preceding the appearance of seizures. Based on the number of spikes per event, there was a natural separation between seizures and shorter interictal events. Two distinct spatial regions were seen: an epileptic focus that grew in size as activity progressed, and an inhibitory surround that exhibited a distinct relationship with the focus both on the surface and in the depth of the cortex. Epileptiform activity in the cortical laminae was seen concomitant with activity on the surface. Focus spikes appeared earlier on electrodes deeper in the cortex, suggesting that deep cortical layers may be integral to recruiting healthy tissue into the epileptic network and could be a promising target for interventional devices. Our study may inform more effective therapies to prevent seizure generation and spread in localization-related epilepsies. NEW & NOTEWORTHY We induced local epileptiform activity and recorded continuous, high-resolution local field potentials from the surface and depth of the visual cortex in anesthetized cats. Our results reveal a consistent pattern of ictogenesis, characterize the spatial spread of the epileptic focus and its relationship with the inhibitory surround, and show that focus activity within events appears earliest in deeper cortical layers. These findings have potential implications for the monitoring and treatment of refractory epilepsy.

Changes in the spatiotemporal pattern of spontaneous activity across a cortical column after noise trauma

2021 ◽  
Author(s):  
Vinay Parameshwarappa ◽  
Laurent Pezard ◽  
Arnaud Jean Norena
Keyword(s):  
Hearing Loss ◽  
Spontaneous Activity ◽  
Local Field ◽  
Local Field Potentials ◽  
Spatiotemporal Pattern ◽  
Noise Induced Hearing Loss ◽  
Field Potentials ◽  
Cortical Column ◽  
Cortical Layers ◽  
Noise Trauma

In the auditory modality, noise trauma has often been used to investigate cortical plasticity as it causes cochlear hearing loss. One limitation of these past studies, however, is that the effects of noise trauma have been mostly documented at the granular layer, which is the main cortical recipient of thalamic inputs. Importantly, the cortex is composed of six different layers each having its own pattern of connectivity and specific role in sensory processing. The present study aims at investigating the effects of acute and chronic noise trauma on the laminar pattern of spontaneous activity in primary auditory cortex of the anesthetized guinea pig. We show that spontaneous activity is dramatically altered across cortical layers after acute and chronic noise-induced hearing loss. First, spontaneous activity was globally enhanced across cortical layers, both in terms of firing rate and amplitude of spike-triggered average of local field potentials. Second, current source density on (spontaneous) spike-triggered average of local field potentials indicates that current sinks develop in the supra- and infragranular layers. These latter results suggest that supragranular layers become a major input recipient and that the propagation of spontaneous activity over a cortical column is greatly enhanced after acute and chronic noise-induced hearing loss. We discuss the possible mechanisms and functional implications of these changes.

scholarly journals Pattern motion selectivity of local field potentials in macaque visual cortex

2010 ◽  
Vol 9 (8) ◽  
pp. 740-740
Author(s):  
F. A. Khawaja ◽  
J. M. G. Tsui ◽  
C. C. Pack
Keyword(s):  
Visual Cortex ◽  
Local Field ◽  
Local Field Potentials ◽  
Field Potentials ◽  
Pattern Motion

scholarly journals Dynamic communication of attention signals between the LGN and V1

2018 ◽  
Vol 120 (4) ◽  
pp. 1625-1639 ◽  
Author(s):  
Vanessa L. Mock ◽  
Kimberly L. Luke ◽  
Jacqueline R. Hembrook-Short ◽  
Farran Briggs
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Local Field ◽  
Visual Information ◽  
Local Field Potentials ◽  
Field Potentials ◽  
Information Communication ◽  
Attentional Modulation ◽  
Visual Thalamus ◽  
The Impact

Correlations and inferred causal interactions among local field potentials (LFPs) simultaneously recorded in distinct visual brain areas can provide insight into how visual and cognitive signals are communicated between neuronal populations. Based on the known anatomical connectivity of hierarchically organized visual cortical areas and electrophysiological measurements of LFP interactions, a framework for interareal frequency-specific communication has emerged. Our goals were to test the predictions of this framework in the context of the early visual pathways and to understand how attention modulates communication between the visual thalamus and primary visual cortex. We recorded LFPs simultaneously in retinotopically aligned regions of the visual thalamus and primary visual cortex in alert and behaving macaque monkeys trained on a contrast-change detection task requiring covert shifts in visual spatial attention. Coherence and Granger-causal interactions among early visual circuits varied dynamically over different trial periods. Attention significantly enhanced alpha-, beta-, and gamma-frequency interactions, often in a manner consistent with the known anatomy of early visual circuits. However, attentional modulation of communication among early visual circuits was not consistent with a simple static framework in which distinct frequency bands convey directed inputs. Instead, neuronal network interactions in early visual circuits were flexible and dynamic, perhaps reflecting task-related shifts in attention. NEW & NOTEWORTHY Attention alters the way we perceive the visual world. For example, attention can modulate how visual information is communicated between the thalamus and cortex. We recorded local field potentials simultaneously in the visual thalamus and cortex to quantify the impact of attention on visual information communication. We found that attentional modulation of visual information communication was not static, but dynamic over the time course of trials.

scholarly journals Low-Frequency Local Field Potentials and Spikes in Primary Visual Cortex Convey Independent Visual Information

2008 ◽  
Vol 28 (22) ◽  
pp. 5696-5709 ◽  
Author(s):  
A. Belitski ◽  
A. Gretton ◽  
C. Magri ◽  
Y. Murayama ◽  
M. A. Montemurro ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Local Field ◽  
Visual Information ◽  
Local Field Potentials ◽  
Low Frequency ◽  
Field Potentials

scholarly journals High-resolution local field potentials measured with deep brain stimulation arrays

2018 ◽  
Vol 15 (4) ◽  
pp. 046019 ◽  
Author(s):  
Simeng Zhang ◽  
Allison T Connolly ◽  
Lauren R Madden ◽  
Jerrold L Vitek ◽  
Matthew D Johnson
Keyword(s):  
Deep Brain Stimulation ◽  
High Resolution ◽  
Local Field ◽  
Brain Stimulation ◽  
Local Field Potentials ◽  
Field Potentials ◽  
Deep Brain
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