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lfp rat epilepsy

Ana Ledo, Cátia F Lourenço, João Laranjinha, Greg A Gerhardt, Rui M Barbosa
Seizures are paroxysmal events in which increased neuronal activity is accompanied by an increase in localized energetic demand. The ability to simultaneously record electrical and chemical events using a single sensor poses a promising approach to identify seizure onset zones in the brain. In the present work, we used ceramic-based platinum microelectrode arrays (MEAs) to perform high-frequency amperometric recording of local pO2 and local field potential (LFP)-related currents during seizures in the hippocampus of chronically implanted freely moving rats...
November 7, 2017: Analytical Chemistry
Marigowda Vrinda, Arun Sasidharan, Sahajan Aparna, Bettadapura N Srikumar, Bindu M Kutty, Byrathnahalli S Shankaranarayana Rao
OBJECTIVE: Temporal lobe epilepsy (TLE) is commonly associated with depression, anxiety, and cognitive impairment. Despite significant progress in our understanding of the pathophysiology of TLE, it remains the most common form of refractory epilepsy. Enriched environment (EE) has a beneficial effect in many neuropsychiatric disorders. However, the effect of EE on cognitive changes in chronic TLE has not been evaluated. Accordingly, the present study evaluated the effects of EE on chronic epilepsy-induced alterations in cognitive functions, electrophysiology, and cellular changes in the hippocampus...
July 2017: Epilepsia
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
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
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
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
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
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
Sam Harris, Luke Boorman, Michael Bruyns-Haylett, Aneurin Kennerley, Hongtao Ma, Mingrui Zhao, Paul G Overton, Theodore H Schwartz, Jason Berwick
OBJECTIVE: Whether epileptic events disrupt normal neurovascular coupling mechanisms locally or remotely is unclear. We sought to investigate neurovascular coupling in an acute model of focal neocortical epilepsy, both within the seizure onset zone and in contralateral homotopic cortex. METHODS: Neurovascular coupling in both ipsilateral and contralateral vibrissal cortices of the urethane-anesthetized rat were examined during recurrent 4-aminopyridine (4-AP, 15 mm, 1 μl) induced focal seizures...
September 2014: Epilepsia
Antonio G Zippo, Sara Nencini, Gian Carlo Caramenti, Maurizio Valente, Riccardo Storchi, Gabriele E M Biella
Current neurophysiological research has the aim to develop methodologies to investigate the signal route from neuron to neuron, namely in the transitions from spikes to Local Field Potentials (LFPs) and from LFPs to spikes. LFPs have a complex dependence on spike activity and their relation is still poorly understood(1). The elucidation of these signal relations would be helpful both for clinical diagnostics (e.g. stimulation paradigms for Deep Brain Stimulation) and for a deeper comprehension of neural coding strategies in normal and pathological conditions (e...
2014: Journal of Visualized Experiments: JoVE
Marina V Sysoeva, Evgenia Sitnikova, Ilya V Sysoev, Boris P Bezruchko, Gilles van Luijtelaar
BACKGROUND: Advanced methods of signal analysis of the preictal and ictal activity dynamics characterizing absence epilepsy in humans with absences and in genetic animal models have revealed new and unknown electroencephalographic characteristics, that has led to new insights and theories. NEW METHOD: Taking into account that some network associations can be considered as nonlinear, an adaptive nonlinear Granger causality approach was developed and applied to analyze cortico-cortical, cortico-thalamic and intrathalamic network interactions from local field potentials (LFPs)...
April 15, 2014: Journal of Neuroscience Methods
Kenichi Usami, Ryuji Kano, Kensuke Kawai, Takahiro Noda, Tomoyo I Shiramatsu, Nobuhito Saito, Hirokazu Takahashi
Vagus nerve stimulation (VNS) is a palliative treatment for intractable epilepsy. Therapeutic mechanisms of VNS have not been elucidated. In this study, we measured the local field potential (LFP) with high-spatial resolution using a microelectrode array in adult rats, and analyzed VNS-evoked phase modulation at a local network level. Eight adult Wistar rats (270 - 330 g) were used. Each rat underwent implantation of VNS system (Cyberonics, Houston, TX., USA) under 1.5% isoflurane anesthesia. One week after implantation, right temporal craniotomy was performed under the same as previous anesthesia...
2013: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
Gregory R Richard, Ali Titiz, Anna Tyler, Gregory L Holmes, Rod C Scott, Pierre-Pascal Lenck-Santini
Hippocampal theta rhythm is believed to play a critical role in learning and memory. In animal models of temporal lobe epilepsy (TLE), there is evidence that alterations of hippocampal theta oscillations are involved in the cognitive impairments observed in this model. However, hippocampal theta frequency and amplitude at both the local field potential (LFP) and single unit level are strongly modulated by running speed, suggesting that the integration of locomotor information into memory processes may also be critical for hippocampal processing...
December 2013: Hippocampus
Dane W Grasse, Suganya Karunakaran, Karen A Moxon
The role of inhibitory neuronal activity in the transition to seizure is unclear. On the one hand, seizures are associated with excessive neuronal activity that can spread across the brain, suggesting run-away excitation. On the other hand, recent in vitro studies suggest substantial activity of inhibitory interneurons prior to the onset of evoked seizure-like activity. Yet, little is known about the behavior of interneurons before and during spontaneous seizures in chronic temporal lobe epilepsy. Here, we examined the relationship between the on-going local field potential (LFP) and the activity of populations of hippocampal neurons during the transition to spontaneous seizures in the pilocarpine rat model of epilepsy...
October 2013: Experimental Neurology
Andrew J Watrous, Darrin J Lee, Ali Izadi, Gene G Gurkoff, Kiarash Shahlaie, Arne D Ekstrom
Rhythmic oscillations within the 3-12 Hz theta frequency band manifest in the rodent hippocampus during a variety of behaviors and are particularly well characterized during spatial navigation. In contrast, previous studies of rhythmic hippocampal activity in primates under comparable behavioral conditions suggest it may be less apparent and possibly less prevalent, or even absent, compared with the rodent. We compared the relative presence of low-frequency oscillations in rats and humans during spatial navigation by using an oscillation detection algorithm ("P-episode" or "BOSC") to better characterize their presence in microelectrode local field potential (LFP) recordings...
August 2013: Hippocampus
Mitsuhiro Fukuda, Alberto L Vazquez, Xiaopeng Zong, Seong-Gi Kim
This article describes the effects of dexmedetomidine (DEX) - the active ingredient of medetomidine, which is the latest popular sedative for functional magnetic resonance imaging (fMRI) in rodents - on multiple unit activity, local field potential (LFP), cerebral blood flow (CBF), pial vessel diameter [indicative of cerebral blood volume (CBV)], and blood oxygenation level-dependent (BOLD) fMRI. These measurements were obtained from the rat somatosensory cortex during 10 s of forepaw stimulation. We found that the continuous intravascular systemic infusion of DEX (50 μg/kg/h, doses typically used in fMRI studies) caused epileptic activities, and that supplemental isoflurane (ISO) administration of ~0...
January 2013: European Journal of Neuroscience
Thomas W Zheng, Terence J O'Brien, Margaret J Morris, Christopher A Reid, Valentina Jovanovska, Patrick O'Brien, Leena van Raay, Arun K Gandrathi, Didier Pinault
PURPOSE:   The origin of bilateral synchronous spike-and-wave discharges (SWDs) that underlie absence seizures has been widely debated. Studies in genetic rodent models suggest that SWDs originate from a restricted region in the somatosensory cortex. The properties of this initiation site remain unknown. Our goal was to characterize the interictal, preictal and ictal neuronal activity in the primary and secondary cortical regions (S1, S2) and in the adjacent insular cortex (IC) in Genetic Absence Epilepsy Rats from Strasbourg (GAERS)...
November 2012: Epilepsia
C G Dulla, H Tani, J Brill, R J Reimer, J R Huguenard
Cortical malformations can cause intractable epilepsy, but the underlying epileptogenic mechanisms are poorly understood. We used high-speed glutamate biosensor imaging to ask how glutamatergic signaling is altered in cortical malformations induced by neonatal freeze-lesions (FL). In non-lesion neocortical slices from 2 to 8week old rats, evoked glutamate signals were symmetrical in the medio-lateral axis and monotonic, correlating with simple, brief (≈50ms) local field potentials (LFPs). By contrast, in FL cortex glutamate signals were prolonged, increased in amplitude, and polyphasic, which paralleled a prolongation of the LFP...
January 2013: Neurobiology of Disease
Chi-Han Wang, Chou P Hung, Ming-Teh Chen, Yang-Hsin Shih, Yung-Yang Lin
Status epilepticus (SE), a pro-epileptogenic brain insult in rodent models of temporal lobe epilepsy, is successfully induced by pilocarpine in some, but not all, rats. This study aimed to identify characteristic alterations within the hippocampal neural network prior to the onset of SE. Sixteen microwire electrodes were implanted into the left hippocampus of male Sprague-Dawley rats. After a 7-day recovery period, animal behavior, hippocampal neuronal ensemble activities, and local field potentials (LFP) were recorded before and after an intra-peritoneal injection of pilocarpine (350 mg/kg)...
2012: PloS One
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