Local field potential

…dynamics, which are reflected in the local field potential (LFP). While recent studies in mice have linked oscillations driven by artificial stimuli to specific thalam

Segmenting vocalizations into distinct units is essential for interpreting sounds. Songbirds, especially the zebra finch with its hierarchical song structure, provide valuable models for studying neural representations of complex sounds. In this study, we recorded zebra finches' neural activity from the auditory pallium during song processing using a movable electrode array, collecting data from 51 recording sites. We employed stacked bidirectional long short-term memory (BiLSTM) deep neural networks to decode the amplitude envelope and time-locked envelope features of the songs. To evaluate h

Interictal epileptiform discharges (IEDs) are brief, sporadic, pathologic electrical bursts in the brains of patients with epilepsy. IEDs represent an important disease biomarker for tracking seizure risk and they also convey direct pathophysiological impacts including on cognitive function. While most work in human IED mechanisms has targeted the population-level neural activity using macro-electrode recordings, the single-neuron mechanisms of IEDs across the depth of human cortical lamina in vivo are largely unknown. We leveraged high-density Neuropixels probes to evaluate single-neuron acti

Traveling waves (TWs) in the brain are a form of neural synchrony. They have been observed across various regions, including the visual cortex and hippocampus, during both spontaneous and task-related activities. These waves are believed to play crucial roles in cognitive processes such as sensory perception and working memory. However, most identified TWs propagate along the cortical surface, leaving it unclear whether they also travel through the depth of the cortex. We address this gap by analyzing laminar TWs of macaque visual areas V1 and V4. We analyzed neural activities recorded from mu

With advances in high-density epicortical electrophysiological recordings (i.e., ECoGs), it became possible to investigate precise spatio-temporal evolution of neural dynamics behind various cognitive functions. This improved resolution allowed for investigation of until now largely disregarded spatial features of neuronal oscillations and challenged the conventional view of global zero-lag synchrony as a basis of neuronal communication. More specifically, it revealed structured phase-offsets in superficial cortical singals corresponding to wave-like dynamics. Further investigation of single-c

Auditory decoding of temporal features is a complex process in which vocalizations such as birdsongs are segmented into distinct auditory units, a crucial step in transforming sound into meaning. The songbird auditory system offers a valuable model for studying the neural representation of complex sounds. The hierarchical structure of the Zebra Finches' song makes it ideal for in-depth analysis of auditory decoding. We use stacked Bidirectional Long Short-Term Memory (BiLSTM) deep neural networks to decode the amplitude envelope and the time-locked envelope features of zebra finch songs. To a

…The advent of an exact mean-field theory for networks of quadratic integrate-and-fire (QIF) neurons represents a significant leap forward in our comprehension of the link between microscale neural mechanisms and mesoscopic brain activity [1]. This model establishes a robust coupling between two biophysically relevant macroscopic quantities: the firing rate and the mean membrane potential, which collectively drive the ev

The amyloid-β precursor protein (APP) is a transmembrane protein constitutively expressed in the brain and highly implicated in Alzheimer’s disease aetiology. We previously identified a novel cleavage site of APP, the η-secretase site (Willem et al. Nature 2015, PMID:26322584). Peptides resulting from this cleavage and α- or β-secretase-dependent proteolysis are the extracellular soluble AETA peptides (Aη-α or Aη-β, respectively). Our previous work also demonstrated that AETA modulates synaptic plasticity and significantly reduces calcium activity in the hippocampus (HPC) in vivo. These result

For the long term aim to develop a visual cortical prosthesis, optogenetic stimulation of primary visual cortex (V1) provides a more specific alternative to electrical stimulation. However, adoption of optogenetic techniques from rodents to macaques as an intermediate step towards humans has proven to be challenging. Here we present prelimnary results, directly comparing effects obtained from optogenetic vs electrical stimulation of macaque V1.We injected AAV9-CamKIIa-ChrimsonR-mScarlet-KV2.1 into macaque V1 under electrophysiological guidance. We first investigated neural activity in response

…488uM thick hippocampal brain slices, local field potential (LFP) recordings were conducted and analyzed for changes in sharp wave ripple (SWR) complexes. In order to assess in-vivo changes

…medial temporal lobe relative to the local theta rhythm. 18 epilepsy patients participated in the task and contributed to 27 experimental sessions. We extracted single-neuron action potentials fro

…bulb by measuring changes in the local field potential. We reco

…We recorded single units and local field potential (LFP) activity from primary visual cortex in awake mice engaged in a visual oddball task. Relative to stimulus onset, we distinguish early (50-200ms) and late (200-400ms) neural response windows, a choice compatible

GABAergic inhibitory Fast Spiking (FS) basket cells (BCs) are recognized for their integral role in shaping learning and memory. This study delves into the orchestration of these processes by FS BCs, particularly their involvement in controlling hippocampal high-frequency gamma oscillations (80-200 Hz) coupled with theta oscillatory activity (3-10 Hz). While existing research predominantly explores the connectivity of these neurons during memory-related rhythms, our investigation highlights an additional layer of subcellular complexity. Recent modeling and experimental findings reveal that FS

The variability in brain activity and dynamical regimes across diverse levels of consciousness have been extensively investigated. However, a comprehensive quantification of these variations is still lacking.This work uses multiple computational strategies to study the mesoscale dynamics and the network topology of neuronal ensembles across different levels of consciousness, focusing on wakefulness, anesthesia, and awakening. The data were acquired by two chronically implanted multielectrode arrays (Utah 96), placed in the dorsal prefrontal cortex (dPFC) and dorsal premotor cortex (PMd) of two

The local field potential (LFP) is an important brain signal to study due to its role in neural mechanisms such as visual perception and decision making, and in brain-computer interface development. Investigating LFPs often involves complex, biophysically detailed computational models, which face significant computational demands.Addressing this, we developed a simplified computational model of a cortical column representing the mouse V1 area, balancing morphological realism and practicality for large-network simulations. The model includes 17 sub-populations encompassing pyramidal neurons, PV

…to stimulate neuronal populations by locally changing the temperature within the brain tissue. Sleep and neural activity during sleep are highly temperature-dependent. During anesthetized in vivo measurements, the low-frequency components increase compared to vigilance. Therefore, we examined the changes in the frequency bands corresponding to delta and theta waves and sleep spindles during continuous infrared stimulation. The experimental device used for INM was a sharp-tip optrode, that holds an embedded waveguide that transmits in

AIMS: Sharp-wave ripples (SWR) are high frequency events recorded in the local field potential (LFP) of the hippocampus of rodents and humans. During neurological conditions such as epilepsy and Alzheimer’s disease, changes on the waveforms of SWRs are considered as biomarkers of dysfunction. However, SWR features cannot be fully characterized by spectral methods alone.METHODS: Here, we introduce a machine learning (ML) toolbox resulting from a community-based hackathon, that operates over high-density LFP recordings to detect hippocampal SWR. We train a wide variety of ML architectures (suppo

Ripples (strong, short-lived oscillations in the local field potential associated with memory consolidation) have been previously reported in several brain areas including the hippocampus and neocortex. Compared to hippocampal ripples, relatively little is known about cortical ripples in terms of their spread and function. We inspected the ripple activity in the frequency range of 70-150 Hz in V1 and V4 of two macaque monkeys implanted with 16 Utah electrode arrays each [1]. The activity was recorded during resting state with occasional periods of drowsing. We observed prominent events with hi

Plant-derived flavonoids have been demonstrated to enhance cognitive function in various organisms, including invertebrates. In the pond snail Lymnaea stagnalis, epicatechin facilitates memory formation through conditioned taste aversion (CTA) training. These snails were categorized into two groups: "good learner" and "poor learner", based on their feeding behaviour 24hours after CTA training. The "good learner" snails showed at least a 40% reduction in feeding behaviour compared to the pre-test levels, while the others were categorized as "poor learner". This study first investigated the effe

…a sensory surprise signal in the local field potential (LFP) in the primary visual cortex (V1) of the anesthetized mouse in response to contrast rate change – a complex, time dependent stimulus parameter. We investigate the population activity responsible for this surprise signal and identify neuronal subgroups

…of population signals such as the local field potential (LFP) is unknown. To address this, we simultaneously recorded LFP and multi-unit spiking activity in 8 different cortical and subcortical brain areas of macaque monkeys. We applied Fourier-based waveform analysis to LFP oscillations and syst

The precise relationship between cortical activity in the sensory areas and perception remains elusive. The perception of a given sensory stimulus can vary depending on the state of ongoing neural activity. Previous electroencephalogram (EEG) studies in humans have demonstrated distinctions in the power and phase angle of alpha oscillations (8-12 Hz) in the occipital region just before the stimulus onset between successfully detected (hits) and undetected (miss) trials (Busch et al., 2009; Dugué et al., 2011). Additionally, electrical microstimulation of V4 has shown to enhance performance in

…Here, we investigated the local activity of the primary somatosensory or barrel cortex (S1) in naturally sleeping head-fixed male mice during REM. Through local field potential (LFP) recordings, we uncovered local appearances of spindle waves in the barrel cort