Local field potentials

Local field potentials (LFPs) of different brain regions are contingent on their individual state and functions. While features of LFPs have been used to distinguish brain regions, no study has attempted to determine the precision with which LFPs can infer the recording positions across the whole brain. To tackle this problem, we hypothesize that tiny differences in LFPs from brain regions and their subregions are separable by using state-of-the-art deep learning methods. We implemented four models to best learn the invariant representations and overcome the predictable noise sources from elec

Every day, we make decisions between multidimensional options. Learning each option’s value by simultaneously attending to all its dimensions is challenging. However, humans navigate this complexity by selectively focusing on relevant information, making real-world, multidimensional reinforcement learning (RL) tractable. Neuroimaging has identified correlates of attention and value learning in the lateral prefrontal (LPFC) and orbitofrontal (OFC) cortex, respectively, yet these methods fall short in elucidating the physiological mechanisms by which these regions coordinate during multidimensio

…such as neuronal spiking activity, local field potentials (LFPs), and behavioral signals capture various aspects of brain processes. By leveraging the complementary strengths of different modalities, multimodal fusion can not only construct a rich and unified representation of brain processes, but also address the limitations of single-modality analyses---such as incomplete or noisy data. An exciting recent direction has been to build models of simultaneously recorded neural and

…(30-120Hz), detectable with Local Field Potentials (LFPs), are classically analyzed through massive trial averages. This approach leaves us with one average oscillation shape, one mean power and a view based on rigid frequency bands. Consistently, mechanisms based on biophysical models of neural networks typically predict periodic oscillations (e.g. PING models [1]). The functional role of oscillations have been largely investigated in the hippocampus, where, different gamma-f

In visual scenes, the presence of corner elements greatly simplifies object recognition [1]. It has been suggested that cortical area V4 is responsible for the processing of these elements, since neurons exhibit selectivity for different curvatures [2]. However, V4 response properties and their contribution to contour integration or shape completion are still far from being understood. We investigated visually-evoked responses of macaque V4 neurons to sparse random stimuli, composed of angled segments pointing in two directions like clock hands (Fig 1a). Recordings were obtained using a 96-cha

…measurements such as spikes, local field potentials and EEG.

Individual neurons’ action potentials (APs) have a dynamic waveform, the shape of which differs by neuron subtype and species. In analyses of single-unit data, however, this waveform is reduced to a binary “all-or-nothing” event, with systems and cognitive neuroscience focusing on the number and timing of spike events. This analytical convenience has, in turn, resulted in computational theories of neural coding that assume binarity.Despite this assumption, a considerable body of evidence shows that AP waveforms exhibit systematic, within-neuron variation that may contribute additional informat

Power spectra of local field potentials contain an aperiodic component that is believed to reflect the excitation/inhibition balance. Several studies have indicated that the aperiodic exponent is sensitive to levodopa in Parkinson’s disease, but there is no clear evidence of its relationship to PD motor symptoms. This study aims to explore the correlation between the aperiodic exponent of subthalamic nucleus activity and rigidity and bradykinesia.Fourteen PD patients underwent bilateral STN DBS surgery with temporary leads externalization. LFPs were recorded in OFF and ON states several days a

Astrocytes interact with neurons at a cellular and molecular level, modulating the synaptic formation, maturation, and function. Their unique morphology allows them to contact synaptic structures to sense, process, and respond to incoming signals. Astrocyte activation leads to intracellular calcium-dependent processes that ultimately modulate circuit function and animal behavior. The IP3 receptor type 2 knockout (IP3R2 KO) mouse model lacks calcium elevations upon astrocytic activation and, therefore, is a good model for studying the roles of intracellular calcium signaling in circuit function

…the theta oscillation, as measured by local field potentials (LFP), governs hippocampal place cell firing. By introducing a new method referred to as state-conditioned decoding, we uncover a different cross-scale hippocampal modulation. Unlike in phase precession, here the LFP’s spectral properties (i.e., instantaneous frequency and amplitude) modulate the firing

…activity in hippocampal CA2 subfield, a region that plays a crucial role in the formation and

Brain oscillatory dynamics are ubiquitous signatures of operating neural circuits. Multiple oscillations have been described in many neural structures of the rodent brain, being commonly associated with various behaviours, computations, and codes, in the sensory, cognitive, and motor domains. The extent to which such oscillatory organisation of neural activity features the human brain remains elusive. To contribute to such an investigation, here we present ongoing cross-species work where we apply the same intra-cranial multi-channel recording technique and analytical framework to cortical and

…Here we characterized local field potentials (LFPs) within mPFC with a focus on the detection of beta bursts – discrete oscillatory events in t

“Cerebellar Mutism” is a challenging problem after resection of pediatric tumors in cerebellar midline structures, with the nucleus fastigii regarded relevant. Although the symptoms are mainly transient, children often have long-term social and cognitive deficits. We already showed that juvenile rats with lesions of the cerebellar fastigial nucleus show behavioral deficits and altered neural activity in the medial prefrontal cortex (mPFC). In our study, we recorded prefrontal neural activity during behavioral testing for attention and decision-making. Rats (lesion [n=9], sham-lesion [n=6], naï

Antibiotics are tremendously beneficial in reducing mortality rates by combating infections but their excessive use has led to severe antibiotic resistance worldwide. The ingestion of oral antibiotics dramatically alters the gut microbiome. Critically, there is limited understanding of the effects of a dysfunctional microbiome on brain function. Male C57BL/6J mice (2–4 months) were given drinking water containing antibiotics (ABX group; ampicillin, neomycin, gentamicin, metronidazole, and vancomycin) or untreated water (CON group). Separate cohorts received butyrate, a key microbiome-derived m

…synapses shape oscillatory dynamics in local field potentials (LFPs) or non-invasive E/MEG recordings, and how changes in NMDA transmission can be inferred from such measures of mass activity. To address these issues, we developed a recurrent network model of excitatory (E) and inhibi

Neural probes made of flexible and soft materials typically have a limited shank length, restricting access to deeper brain areas. In this study, we developed single-shank polyimide-based neural probes with an ultra-long implantable shank, enabling penetration depths of several centimeters. The probes are composed of multiple components assembled using gold-gold thermocompression bonding after wafer-level fabrication, with the assembled devices exceeding a length of 300 mm. The tapered shank is approximately 200 µm wide, 15 µm thick and contains 32 linearly placed iridium-oxide microelectrodes

Communication between the hippocampus and the prefrontal cortex (HPC, PFC) is necessary for consolidating memories during both wakefulness and sleep. The activity-regulated gene Arc/Arg3.1 is essential in mediating memory consolidation1 and has been shown to influence memory-associated network activity2,3.We here investigate the impact of hippocampal Arc/Arg3.1 expression on network dynamics between the HPC and PFC during spontaneous brain state changes in sleep induced by urethane anesthesia. We used virus-mediated conditional deletion of Arc/Arg3.1 in the hippocampus and silicon probes to re

Perceptual sensitivity varies from moment-to-moment with fluctuations in the gain of sensory-evoked responses. We previously found that intrinsic traveling waves (iTWs) of activity in marmoset Area MT regulate the gain of evoked responses for targets presented near perceptual threshold and correlate with the monkey’s detection performance (Davis, Muller, et al. Nature 2020; Davis, Benigno, et al. Nat. Communi. 2021). Here we ask whether target detection also depends on the spiking activity of neurons beyond the retinotopic locus of the target (off-target locations). We hypothesized that activi

Many of our daily actions require interacting with others. Despite this attitude, the neural mechanisms underpinning motor control in the domain of social interaction remain poorly understood, especially at single cell or population level. Our previous studies demonstrated that both monkeys and humans adapt their behaviour when acting in a dyadic context, and that macaques, as humans, leverage on a “we-representation”, suggesting phylogenetically preserved neural processes. At neural level, we showed in macaque dorsal premotor (PMd/F2) cortex the existence of a population of cells, preferentia

Alzheimer's disease (AD) is a progressive neurodegenerative condition characterized by a significant decline in episodic memory. More recent research indicates that impairments in spatial navigation may serve as a more sensitive biomarker for AD compared to episodic memory alterations. To study the cellular mechanisms behind spatial memory and navigation deficits in AD we used the APP/PS1 mouse model of amyloidosis. To assess spatial memory updating, a non-stressful paradigm called Objects in Updated Locations (OUL) was employed. This task allows the quantification of the different times of ex

Growing evidence implicates the gut microbiome in brain health and disease. Since worldwide consumption of oral antibiotics continues to rise, it is imperative to understand how microbiome-depleting antibiotics affect cognition. We studied a murine model in which mice drank water containing an antibiotic cocktail (ABX group) or untreated water (CON group). Separate cohorts received butyrate, a key microbiome-derived metabolite, either in the presence (ABXBA group) or absence (BA group) of antibiotics. The four groups were tested at 4 weeks of treatment. We assessed hippocampus–related spatial

Lesion studies have elucidated the distinct roles played by different areas in the prefrontal cortex (PFC) in guiding behaviour according to abstract rules, as observed in a macaque-adapted version of the Wisconsin Card Sorting Test (WCST). Nevertheless, we do not fully understand how these functional specialisations relate to the underlying neuronal activity across these different prefrontal regions. In this study, we present novel insights derived from our multi-area multi-electrode recording in non-human primates (NHPs). We chronically implanted Utah arrays in dorsolateral PFC, ventrolatera

Flexible routing of visual input signals has been linked to changing patterns of synchrony between gamma rhythms of distant neural groups. It has been proposed that attention increases distant gamma-band synchrony by increasing the gamma frequency of the sender group processing the attended stimulus. This stimulus is subsequently preferentially processed. However, the frequency of gamma activity fluctuates over time, varies between areas, and depends on stimulus characteristics, which may complicate entrainment between oscillators. Here, we investigate the relationship between the frequency of