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Lfp epilepsy

Mehdi Aghagolzadeh, Leigh R Hochberg, Sydney S Cash, Wilson Truccolo, Mehdi Aghagolzadeh, Leigh R Hochberg, Sydney S Cash, Wilson Truccolo, Sydney S Cash, Wilson Truccolo, Mehdi Aghagolzadeh, Leigh R Hochberg
The need for new therapeutic interventions to treat pharmacologically resistant focal epileptic seizures has led recently to the development of closed-loop systems for seizure control. Once a seizure is predicted/detected by the system, electrical stimulation is delivered to prevent seizure initiation or spread. So far, seizure prediction/detection has been limited to tracking non-invasive electroencephalogram (EEG) or intracranial EEG (iEEG) signals. Here, we examine seizure prediction based on local field potentials (LFPs) from a small neocortical patch recorded via a 10×10 microelectrode array implanted in a patient with focal seizures...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
Anthony J Williams, Chen Zhou, Qian-Quan Sun
Focal cortical dysplasias (FCDs) are a common cause of brain seizures and are often associated with intractable epilepsy. Here we evaluated aberrant brain neurophysiology in an in vivo mouse model of FCD induced by neonatal freeze lesions (FLs) to the right cortical hemisphere (near S1). Linear multi-electrode arrays were used to record extracellular potentials from cortical and subcortical brain regions near the FL in anesthetized mice (5-13 months old) followed by 24 h cortical electroencephalogram (EEG) recordings...
2016: Frontiers in Neural Circuits
Samuel A Neymotin, Zoe N Talbot, Jeeyune Q Jung, André A Fenton, William W Lytton
BACKGROUND: Correlated neuronal activity in the brain is hypothesized to contribute to information representation, and is important for gauging brain dynamics in health and disease. Due to high dimensional neural datasets, it is difficult to study temporal variations in correlation structure. NEW METHOD: We developed a multiscale method, Population Coordination (PCo), to assess neural population structure in multiunit single neuron ensemble and multi-site local field potential (LFP) recordings...
January 1, 2017: Journal of Neuroscience Methods
F Vallone, E Vannini, A Cintio, M Caleo, A Di Garbo
Epilepsy is characterized by substantial network rearrangements leading to spontaneous seizures and little is known on how an epileptogenic focus impacts on neural activity in the contralateral hemisphere. Here, we used a model of unilateral epilepsy induced by injection of the synaptic blocker tetanus neurotoxin (TeNT) in the mouse primary visual cortex (V1). Local field potential (LFP) signals were simultaneously recorded from both hemispheres of each mouse in acute phase (peak of toxin action) and chronic condition (completion of TeNT effects)...
September 2016: Physical Review. E
E C Y Ho, Wilson Truccolo
How focal seizures initiate and evolve in human neocortex remains a fundamental problem in neuroscience. Here, we use biophysical neuronal network models of neocortical patches to study how the interaction between inhibition and extracellular potassium ([K (+)] o ) dynamics may contribute to different types of focal seizures. Three main types of propagated focal seizures observed in recent intracortical microelectrode recordings in humans were modelled: seizures characterized by sustained (∼30-60 Hz) gamma local field potential (LFP) oscillations; seizures where the onset in the propagated site consisted of LFP spikes that later evolved into rhythmic (∼2-3 Hz) spike-wave complexes (SWCs); and seizures where a brief stage of low-amplitude fast-oscillation (∼10-20 Hz) LFPs preceded the SWC activity...
October 2016: Journal of Computational Neuroscience
Karishma Chhabria, V Srinivasa Chakravarthy
The motivation of developing simple minimal models for neuro-glio-vascular (NGV) system arises from a recent modeling study elucidating the bidirectional information flow within the NGV system having 89 dynamic equations (1). While this was one of the first attempts at formulating a comprehensive model for neuro-glio-vascular system, it poses severe restrictions in scaling up to network levels. On the contrary, low--dimensional models are convenient devices in simulating large networks that also provide an intuitive understanding of the complex interactions occurring within the NGV system...
2016: Frontiers in Neurology
Beth A Lopour, Richard J Staba, John M Stern, Itzhak Fried, Dario L Ringach
OBJECTIVE: Quantifying the relationship between microelectrode-recorded multi-unit activity (MUA) and local field potentials (LFPs) in distinct brain regions can provide detailed information on the extent of functional connectivity in spatially widespread networks. These methods are common in studies of cognition using non-human animal models, but are rare in humans. Here we applied a neuronal spike-triggered impulse response to electrophysiological recordings from the human epileptic brain for the first time, and we evaluate functional connectivity in relation to brain areas supporting the generation of seizures...
April 2016: Journal of Neural Engineering
Ana Clara Silveira Broggini, Ingrid Miranda Esteves, Rodrigo Neves Romcy-Pereira, João Pereira Leite, Richardson Naves Leão
The pathologically synchronized neuronal activity in temporal lobe epilepsy (TLE) can be triggered by network events that were once normal. Under normal conditions, hippocampus and medial prefrontal cortex (mPFC) work in synchrony during a variety of cognitive states. Abnormal changes in this circuit may aid to seizure onset and also help to explain the high association of TLE with mood disorders. We used a TLE rat model generated by perforant path (PP) stimulation to understand whether synchrony between dorsal hippocampal and mPFC networks is altered shortly before a seizure episode...
May 2016: Experimental Neurology
Ann C Vanleer, Justin A Blanco, Joost B Wagenaar, Jonathan Viventi, Diego Contreras, Brian Litt
OBJECTIVE: Current mapping of epileptic networks in patients prior to epilepsy surgery utilizes electrode arrays with sparse spatial sampling (∼1.0 cm inter-electrode spacing). Recent research demonstrates that sub-millimeter, cortical-column-scale domains have a role in seizure generation that may be clinically significant. We use high-resolution, active, flexible surface electrode arrays with 500 μm inter-electrode spacing to explore epileptiform local field potential (LFP) spike propagation patterns in two dimensions recorded from subdural micro-electrocorticographic signals in vivo in cat...
April 2016: Journal of Neural Engineering
Shennan Aibel Weiss, Catalina Alvarado-Rojas, Anatol Bragin, Eric Behnke, Tony Fields, Itzhak Fried, Jerome Engel, Richard Staba
OBJECTIVE: To characterize local field potentials, high frequency oscillations, and single unit firing patterns in microelectrode recordings of human limbic onset seizures. METHODS: Wide bandwidth local field potential recordings were acquired from microelectrodes implanted in mesial temporal structures during spontaneous seizures from six patients with mesial temporal lobe epilepsy. RESULTS: In the seizure onset zone, distinct epileptiform discharges were evident in the local field potential prior to the time of seizure onset in the intracranial EEG...
January 2016: Epilepsia
Sophie Sakkaki, Giuseppe Gangarossa, Benoit Lerat, Dominique Françon, Luc Forichon, Jean Chemin, Emmanuel Valjent, Mireille Lerner-Natoli, Philippe Lory
T-type (Cav3) calcium channels play important roles in neuronal excitability, both in normal and pathological activities of the brain. In particular, they contribute to hyper-excitability disorders such as epilepsy. Here we have characterized the anticonvulsant properties of TTA-A2, a selective T-type channel blocker, in mouse. Using the maximal electroshock seizure (MES) as a model of tonic-clonic generalized seizures, we report that mice treated with TTA-A2 (0.3 mg/kg and higher doses) were significantly protected against tonic seizures...
February 2016: Neuropharmacology
Fabien B Wagner, Emad N Eskandar, G Rees Cosgrove, Joseph R Madsen, Andrew S Blum, N Stevenson Potter, Leigh R Hochberg, Sydney S Cash, Wilson Truccolo
Some of the most clinically consequential aspects of focal epilepsy, e.g. loss of consciousness, arise from the generalization or propagation of seizures through local and large-scale neocortical networks. Yet, the dynamics of such neocortical propagation remain poorly understood. Here, we studied the microdynamics of focal seizure propagation in neocortical patches (4×4 mm) recorded via high-density microelectrode arrays (MEAs) implanted in people with pharmacologically resistant epilepsy. Our main findings are threefold: (1) a newly developed stage segmentation method, applied to local field potentials (LFPs) and multiunit activity (MUA), revealed a succession of discrete seizure stages, each lasting several seconds...
November 15, 2015: NeuroImage
Teemu Laitinen, Alejandra Sierra, Tamuna Bolkvadze, Asla Pitkänen, Olli Gröhn
Traumatic brain injury (TBI) is a major cause of disability and death in people of all ages worldwide. An initial brain injury caused by external mechanical forces triggers a cascade of tissue changes that lead to a wide spectrum of symptoms and disabilities, such as cognitive deficits, mood or anxiety disorders, motor impairments, chronic pain, and epilepsy. We investigated the detectability of secondary injury at a chronic time-point using ex vivo diffusion tensor imaging (DTI) in a rat model of TBI, lateral fluid percussion (LFP) injury...
2015: Frontiers in Neuroscience
Robert A McGovern, Tarini Ratneswaren, Elliot H Smith, Jennifer F Russo, Amy C Jongeling, Lisa M Bateman, Catherine A Schevon, Neil A Feldstein, Guy M McKhann, Sameer Sheth
Stereotactic Electroencephalography (SEEG) is a technique used to localize seizure foci in patients with medically intractable epilepsy. This procedure involves the chronic placement of multiple depth electrodes into regions of the brain typically inaccessible via subdural grid electrode placement. SEEG thus provides a unique opportunity to investigate brain function. In this paper we demonstrate how SEEG can be used to investigate the role of the dorsal anterior cingulate cortex (dACC) in cognitive control...
2015: Journal of Visualized Experiments: JoVE
Max-Philipp Stenner, Vladimir Litvak, Robb B Rutledge, Tino Zaehle, Friedhelm C Schmitt, Jürgen Voges, Hans-Jochen Heinze, Raymond J Dolan
The nucleus accumbens is thought to contribute to action selection by integrating behaviorally relevant information from multiple regions, including prefrontal cortex. Studies in rodents suggest that information flow to the nucleus accumbens may be regulated via task-dependent oscillatory coupling between regions. During instrumental behavior, local field potentials (LFP) in the rat nucleus accumbens and prefrontal cortex are coupled at delta frequencies (Gruber AJ, Hussain RJ, O'Donnell P. PLoS One 4: e5062, 2009), possibly mediating suppression of afferent input from other areas and thereby supporting cortical control (Calhoon GG, O'Donnell P...
July 2015: Journal of Neurophysiology
Kirill V Nourski, Mitchell Steinschneider, Ariane E Rhone, Hiroyuki Oya, Hiroto Kawasaki, Matthew A Howard, Bob McMurray
High gamma power has become the principal means of assessing auditory cortical activation in human intracranial studies, albeit at the expense of low frequency local field potentials (LFPs). It is unclear whether limiting analyses to high gamma impedes ability of clarifying auditory cortical organization. We compared the two measures obtained from posterolateral superior temporal gyrus (PLST) and evaluated their relative utility in sound categorization. Subjects were neurosurgical patients undergoing invasive monitoring for medically refractory epilepsy...
September 2015: Brain and Language
François Laurent, Jorge R Brotons-Mas, Elena Cid, Diego Lopez-Pigozzi, Manuel Valero, Beatriz Gal, Liset Menendez de la Prida
Coherent neuronal activity in the hippocampal-entorhinal circuit is a critical mechanism for episodic memory function, which is typically impaired in temporal lobe epilepsy. To better understand how this mechanism is implemented and degraded in this condition, we used normal and epileptic rats to examine theta activity accompanying active exploration. Assisted by multisite recordings of local field potentials (LFPs) and layer-specific profiling of input pathways, we provide detailed quantification of the proximodistal coherence of theta activity in the dorsal hippocampus of these animals...
March 18, 2015: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Dion Khodagholy, Jennifer N Gelinas, Thomas Thesen, Werner Doyle, Orrin Devinsky, George G Malliaras, György Buzsáki
Recording from neural networks at the resolution of action potentials is critical for understanding how information is processed in the brain. Here, we address this challenge by developing an organic material-based, ultraconformable, biocompatible and scalable neural interface array (the 'NeuroGrid') that can record both local field potentials(LFPs) and action potentials from superficial cortical neurons without penetrating the brain surface. Spikes with features of interneurons and pyramidal cells were simultaneously acquired by multiple neighboring electrodes of the NeuroGrid, allowing for the isolation of putative single neurons in rats...
February 2015: Nature Neuroscience
W J Lipski, V J DeStefino, S R Stanslaski, A R Antony, D J Crammond, J L Cameron, R M Richardson
Epilepsy is a debilitating condition affecting 1% of the population worldwide. Medications fail to control seizures in at least 30% of patients, and deep brain stimulation (DBS) is a promising alternative treatment. A modified clinical DBS hardware platform was recently described (PC+S) allowing long-term recording of electrical brain activity such that effects of DBS on neural networks can be examined. This study reports the first use of this device to characterize idiopathic epilepsy and assess the effects of stimulation in a nonhuman primate (NHP)...
February 15, 2015: Journal of Neurophysiology
Wilson Truccolo, Omar J Ahmed, Matthew T Harrison, Emad N Eskandar, G Rees Cosgrove, Joseph R Madsen, Andrew S Blum, N Stevenson Potter, Leigh R Hochberg, Sydney S Cash
Seizures are classically characterized as the expression of hypersynchronous neural activity, yet the true degree of synchrony in neuronal spiking (action potentials) during human seizures remains a fundamental question. We quantified the temporal precision of spike synchrony in ensembles of neocortical neurons during seizures in people with pharmacologically intractable epilepsy. Two seizure types were analyzed: those characterized by sustained gamma (∼40-60 Hz) local field potential (LFP) oscillations or by spike-wave complexes (SWCs; ∼3 Hz)...
July 23, 2014: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
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