Search results for "Local field"
showing 7 items of 57 documents
Chronic neural probe for simultaneous recording of single-unit, multi-unit, and local field potential activity from multiple brain sites
2017
Drug resistant focal epilepsy can be treated by resecting the epileptic focus requiring a precise focus localisation using stereoelectroencephalography (SEEG) probes. As commercial SEEG probes offer only a limited spatial resolution, probes of higher channel count and design freedom enabling the incorporation of macro and microelectrodes would help increasing spatial resolution and thus open new perspectives for investigating mechanisms underlying focal epilepsy and its treatment. This work describes a new fabrication process for SEEG probes with materials and dimensions similar to clinical probes enabling recording single neuron activity at high spatial resolution.Polyimide is used as a bi…
Evoked local field potentials can explain temporal variation in blood oxygenation level-dependent responses in rat somatosensory cortex
2010
The aim of this study was to explain the temporal variations between subjects in the blood oxygenation level-dependent (BOLD) response. Somatosensory responses were elicited with the electrical forepaw stimulus at a frequency of 10 Hz in urethane-anesthetized rats, and functional magnetic resonance imaging (fMRI) with BOLD contrast and local field potential (LFP) measurements were performed simultaneously. BOLD fMRI activation was evaluated by two different models, one based on the stimulus paradigm (the block model) and the other on the simultaneously measured evoked LFP responses. In the initial analysis, the LFP model captured the BOLD activation in the primary somatosensory cortex in al…
Deviance detection in sound frequency in simple and complex sounds in urethane-anesthetized rats
2019
Mismatch negativity (MMN), which is an electrophysiological response demonstrated in humans and animals, reflects memory-based deviance detection in a series of sounds. However, only a few studies on rodents have used control conditions that were sufficient in eliminating confounding factors that could also explain differential responses to deviant sounds. Furthermore, it is unclear if change detection occurs similarly for sinusoidal and complex sounds. In this study, we investigated frequency change detection in urethane-anesthetized rats by recording local-field potentials from the dura above the auditory cortex. We studied change detection in sinusoidal and complex sounds in a series of …
Advanced technologies for detecting tremor in Parkinson's disease.
2019
Objective Accurate and reliable detection of tremor onset in Parkinson’s disease (PD) is critical to the success of adaptive deep brain stimulation (aDBS) therapy. Here, we investigated the potential use of feature engineering and machine learning methods for more accurate detection of rest tremor in PD. Methods We analyzed the local field potential (LFP) recordings from the subthalamic nucleus region in 12 patients with PD (16 recordings). To explore the optimal biomarkers and the best performing classifier, the performance of state-of-the-art machine learning (ML) algorithms and various features of the subthalamic LFPs were compared. We further used a Kalman filtering technique in feature…
Auditory cortical and hippocampal local-field potentials to frequency deviant tones in urethane-anesthetized rats: An unexpected role of the sound fr…
2015
Abstract The human brain can automatically detect auditory changes, as indexed by the mismatch negativity of event-related potentials. The mechanisms that underlie this response are poorly understood. We recorded primary auditory cortical and hippocampal (dentate gyrus, CA1) local-field potentials to serial tones in urethane-anesthetized rats. In an oddball condition, a rare (deviant) tone ( p = 0.11) randomly replaced a repeated (standard) tone. The deviant tone was either lower (2200, 2700, 3200, 3700 Hz) or higher (4300, 4800, 5300, 5800 Hz) in frequency than the standard tone (4000 Hz). In an equiprobability control condition, all nine tones were presented at random ( p = 0.11). Diffe…
Antennal lobe representations are optimized when olfactory stimuli are periodically structured to simulate natural wing beat effects
2014
Animals use behaviors to actively sample the environment across a broad spectrum of sensory domains. These behaviors discretize the sensory experience into unique spatiotemporal moments, minimize sensory adaptation, and enhance perception. In olfaction, behaviors such as sniffing, antennal flicking, and wing beating all act to periodically expose olfactory epithelium. In mammals, it is thought that sniffing enhances neural representations; however, the effects of insect wing beating on representations remain unknown. To determine how well the antennal lobe produces odor-dependent representations when wing beating effects are simulated, we used extracellular methods to record neural units an…
Anatomical and electrophysiological study of the vomeronasal circuits: Amygdaloid response to odours and pheromones
2017
Rodents detect information concerning the world around them mainly through two chemosensory systems: the olfactory and the vomeronasal systems. In order to develop an appropriate behavioural response to their environment, these systems exhibit both functional and physiological convergence. Further understanding of the organization and function of the olfactory systems would allow us to comprehend how their information is integrated in the brain. In a first approach we performed a thorough analysis of the connections of key structures involved in the processing of vomeronasal information: the medial (Me) and the posteromedial cortical (PMCo) amygdaloid nucleus. Then, we enquire the populatio…