Publications - Computational Neurophysiology

  • On the boundary conditions of avoidance memory reconsolidation: An attractor network perspective

    In the present work, by adapting the model of Osan et al. (2011) to simulate the experimental protocols of Radiske et al. (2017), we show that such boundary condition is compatible with the dynamics of an attractor network that supports synaptic...
  • Hippocampal CA1 and cortical interictal oscillations in the pilocarpine model of epilepsy

    Quantitative electroencephalogram analysis has been increasingly applied to study fine changes in brain oscillations in epilepsy. Here we aimed to evaluate interictal oscillations using pilocarpine model of epilepsy to identify changes in network synchronization.
  • O papel de oscilações beta2 e de interneurônios OLMa2 da região CA1 do hipocampo de camundongos na memória de reconhecimento de objetos



  • Beta2 oscillations (23–30 Hz) in the mouse hippocampus during novel object recognition

    In the present study we characterised hippocampal beta2 oscillations in mice during an object recognition task. We found prominent bursts of beta2 oscillations in the beginning of novel exploration sessions (four new objects), which could be readily observed by spectral analysis and...
  • S100B protein and neuron-specific enolase as predictors of cognitive dysfunction after coronary artery bypass graft surgery: a prospective observational study

    The study aims to evaluate the association between POCD and serum levels of S100B and NSE after coronary artery bypass grafting surgery (CABG).
  • On the photovoltaic effect in local field potential recordings

    We found that light leads to several artifacts that resemble genuine LFP features in animals with no opsin expression, such as stereotyped peaks at the power spectrum, phase shifts across different recording channels, coupling between low and high oscillation frequencies, and sharp...
  • Nasal respiration entrains delta-frequency oscillations in the prefrontal cortex and hippocampus of rodents

    We further showed that respiration-entrained LFP oscillations were abolished by tracheostomy and restored by rhythmic air puffing into the nasal cavity; moreover, in the hippocampus, RR had the maximum amplitude in the dentate gyrus hilus, the anatomical site where olfactory inputs impinge...
  • Olfactory bulb drives respiration-coupled beta oscillations in the rat hippocampus

    We find that beta oscillations simultaneously appear in HPC and OB and phase-lock across structures. Moreover, Granger causality analysis reveals that OB beta activity drives HPC beta.
  • Parallel detection of theta and respiration-coupled oscillations throughout the mouse brain

    We find that respiration-coupled oscillations can be detected in parallel with theta in several neocortical regions, from prefrontal to visual areas, and also in subcortical structures such as the thalamus, amygdala and ventral hippocampus.
  • Characterizing speed cells in the rat hippocampus

    Here we investigated speed-correlated firing in the hippocampus. We show that CA1 has speed cells that are stable across contexts, position in space, and time.
  • Spike sorting with Gaussian mixture models

    In this study, we explored the performance of Gaussian mixture models (GMMs) in these two steps. We extracted relevant features using a combination of common techniques (e.g., principal components, wavelets) and GMM fitting parameters (e.g., Gaussian distances).
  • Sabores em ondas cerebrais

    Cientistas tentam entender como o cérebro processa informações por meio da atividade individual dos neurônios. Pesquisas recentes mostram como o cérebro apreende e decodifica o que chamamos de realidade.
  • Recording Day and Night: Advice for New Investigators in the Sleep and Memory Field

    The investigation of the sleep-dependent mechanisms of memory processing and consolidation is largely based on the electrophysiological recording of action potentials (spikes), local field potentials (LFPs), and muscle activity from freely behaving rodents.
  • Ventral hippocampal OLM cells control type 2 theta oscillations and response to predator odor.

    Here, we show that optogenetic activation of oriens-lacunosum moleculare (OLM) interneurons in the ventral hippocampus drives type 2 theta. Moreover, we found that type 2 theta generation is associated with increased risk-taking behavior in response to predator odor.
  • OLMa2 cells bidirectionally modulate learning

    Here we set out to determine whether selective modulation of OLMa2 cells in the intermediate CA1 affects learning and memory in vivo.
  • Theta-Gamma Cross-Frequency Analyses (Hippocampus)

    We found a canonical correlation linking speech connectedness and i) functional as well as developmentally relevant structural brain markers (degree centrality from resting state functional imaging and cortical gyrification index) ii) psychometric evaluation of thought disorder iii) aspects of cognitive performance (processing...
  • Respiration-Entrained Brain Rhythms Are Global but Often Overlooked

    We summarize recent evidence showing that nasal respiration entrains oscillations at the same frequency as breathing in several regions of the rodent brain.
  • Asymmetry of the temporal code for space by hippocampal place cells

    Here we show that the spike timing of place cells couples to theta phase before major increases in firing rate, anticipating the animal’s entrance into the classical, rate-based place field.
  • Place and grid cells in a loop: implications for memory function and spatial coding

    Based on the anatomy of the entorhinal-hippocampal circuitry, we constructed a model of place and grid cells organized in a loop to investigate their mutual influence in the establishment of their codes for space.
  • Unveiling Fast Field Oscillations through Comodulation

    Comodulation analysis unveils four different types of fast LFP activity coupled to theta: two oscillations within the traditional gamma band, HFOs, and spike-leaked activity.
  • Selective entrainment of gamma subbands by different slow network oscillations

    Respiration-induced oscillations and the theta rhythm modulate different gamma frequencies, suggesting that the brain uses different frequency channels for transferring different types of information.
  • On cross-frequency phase-phase coupling between theta and gamma oscillations in the hippocampus

    Phase-locking of hippocampal theta and gamma waves has been proposed to support memory formation, but an analysis using robust statistical methods finds no convincing evidence for the phenomenon.
  • A Respiration-Coupled Rhythm in the Rat Hippocampus Independent of Theta and Slow Oscillations

    Hippocampal respiration rhythm in rats. This work shows that the hippocampus produces two low-frequency rhythms at nearby frequencies: one that couples to respiration and another that is coupled to the neocortex. The results support a role for brain oscillations in connecting distant brain...
  • Impaired theta-gamma coupling in APP-deficient mice

    The amyloid precursor protein (APP) is critically involved in the pathophysiology of Alzheimer’s disease, but its physiological functions remain elusive. This work shows that lack of APP reduces oscillatory coupling in voltage recordings from specific brain regions, despite not affecting the amplitude...
  • Hippocampal Respiration-Driven Rhythm Distinct from Theta Oscillations in Awake Mice

    This work demonstrates that the hippocampus of awake mice produces slow oscillations that are entrained by nasal respiration. The rhythm is close in frequency to, but distinct from, classical theta oscillations. The results suggest that respiration-coupled oscillations aid the exchange of information...
  • Multifactoriality in Psychiatric Disorders: A Computational Study of Schizophrenia

    This computational work shows that schizophrenia phenotypes can be produced by a myriad of causes at the molecular and circuit levels, which suggests that unified explanations for either the full syndrome or its behavioral and network endophenotypes are unlikely to be expected...
  • Synaptic Homeostasis and Restructuring across the Sleep-Wake Cycle

    Sleep is critical for hippocampus-dependent memory consolidation. However, the underlying mechanisms of synaptic plasticity are poorly understood. The central controversy is on whether long-term potentiation (LTP) takes a role during sleep and which would be its specific effect on memory....
  • Local Field Potentials in the Gustatory Cortex Carry Taste Information

    We found that the phase and amplitude of multiple LFP frequencies carry information about stimuli, which have specific time courses after stimulus delivery.
  • Efeitos da administração aguda de quetamina sobre as oscilações eletrofisiológicas da região ca1 hipocampal

  • An investigation of Hebbian phase sequences as assembly graphs

    We investigated action potentials recorded from the adult rat hippocampus and neocortex before, during and after novel object exploration (experimental periods).
  • Slow Oscillations in the Mouse Hippocampus Entrained by Nasal Respiration. The Journal of Neuroscience

    In this study, the authors demonstrate the existence of a previously unrecognized type of neuronal rhythm in the mouse hippocampus that is entrained by respiration. The rhythm is close in frequency to classical theta oscillations but can be distinguished by several features...
  • Sonic hedgehog signaling regulates mode of cell division of early cerebral cortex progenitors and increases astrogliogenesis

    In this work, we investigated whether SHH signaling influences the behavior of neural progenitors isolated from the dorsal telencephalon, which generate excitatory neurons and macroglial cells in vitro. We observed that SHH increases proliferation of cortical progenitors and generation of astrocytes, whereas...
  • Increase in Hippocampal Theta Oscillations during Spatial Decision Making.

    In this study, we investigated to what extent spatial decision making modulates hippocampal theta oscillations when controlling for variations in locomotion speed.
  • Detecting cell assemblies in large neuronal populations

    Here we review three linear methods for the detection of cellassemblies in large neuronal populations that rely on principal and independent component analysis.
  • Ketamine alters oscillatory coupling in the hippocampus

    Network interactions that underlie cognitively relevant oscillatory coupling in the hippocampus are altered upon NMDA receptor blockade by ketamine, a pharmacological model of schizophrenia.
  • Os Portões Iluminados da Memória

    Novos marcadores celulares associados a ferramentas optogenéticas têm permitido que pesquisadores compreendam as funções de tipos específicos de neurônios, e, com isso, revelam possíveis mecanismos de processamento de informação no cérebro.
  • Caracterização dos Acoplamentos FAse-Amplitude na Região CA1 do Hipocampo.

  • Global slowing of network oscillations in mouse neocortex by diazepam.

    We therefore analyzed diazepam effects on a large range of cortical network oscillations in freely moving mice, including theta (4e12 Hz), gamma (40e100 Hz) and fast gamma (120e160 Hz) oscillations. We also investigated diazepam effects over the coupling between theta phase and...
  • On High-Frequency Field Oscillations (>100 Hz) and the Spectral Leakage of Spiking Activity.

    Our results argue against the idea that all high-frequency LFP activity stems from spike contamination and suggest avoiding defining brain rhythms solely based on frequency range.
  • Theta-associated high-frequency oscillations (110-160 Hz) in the hippocampus and neocortex.

    We review recent evidence for a novel type of fast cortical oscillatory activity that occurs circumscribed between 110 and 160 Hz, which we refer to as high-frequency oscillations (HFOs).
  • Distinct features of fast oscillations in phasic and tonic rapid eye movement sleep.

    Our data suggest different roles of phasic and tonic REM for information processing or memory formation during sleep.
  • Theta Phase Modulates Multiple Layer-Specific Oscillations in the CA1 Region

    The phase of the hippocampal theta rhythm modulates the amplitude of multiple layer-specific oscillations in CA1.
  • OLM interneurons differentially modulate CA3 and entorhinal inputs to hippocampal CA1 neurons.

    Our results suggest that acetylcholine acting through OLM cells can control the mnemonic processes executed by the hippocampus.
  • Rising Publication Delays Inflate Journal Impact Factors

    Here we point out that the calculation of a journal’s impact factor is mainly based on the date of publication of its articles in print form, despite the fact that most journals now make their articles available online before that date.
  • Serum S100B levels in patients with HTLV-I associated myelopathy/tropical spastic paraparesis.

  • High immunocontent of S100B protein in amniotic fluid of pregnancies with Down syndrome

  • Decreased S100-beta in schizophrenia: preliminary evidence

  • Diagnostico Diferencial dos Quadros Demenciais Associados a Parkinsonismo.

  • Serum S100B levels in patients with Lupus Erythematosus: preliminary observation

  • The Serum S100B Concentration is Age Dependent.

  • Increase in serum S100B protein level after a swimming race.

  • Influence of anticoagulants on the measurement of S100B protein in blood

  • S100B protein and amniotic fluid

  • Interictal serum S100B levels in chronic neurocysticercosis and idiopathic epilepsy

  • Use of fluoxetine for treatment of Machado-Joseph disease: an open-label study

  • Specificity and sensitivity of S100B levels in amniotic fluid for Down syndrome diagnosis

  • Guanosine selectively inhibits locomotor stimulation induced by the NMDA antagonist dizocilpine.

  • Serum S100B in pregnancy-related hypertensive disorders: a case-control study.

  • Half the dose of antipsychotic in case of extrapyramidal symptoms

  • Cinnarizine has an atypical antipsychotic profile in animal models of psychosis.

  • s100b and nse serum concentrations in Machado Joseph disease

  • s100b and nse serum levels ins patients with parkinson's disease

  • Effect of subchronic caffeine treatment on MK-801 induced changes in locomotion, cognition and ataxia in mice..

  • On the simulation of the time-course of dopamine D2 receptor occupancy from the pharmacokinetics of antipsychotics.

  • Atypical antipsychotic profile of flunarizine in animal models

  • A simple webcam-based approach for the measurement of rodent locomotion and other behavioural parameters

  • Serum and cerebrospinal fluid S100B concentrations in patients with neurocysticercosis.

  • Raised serum S100B protein levels in neuropsychiatric lupus.

  • Theoretical insights into the mechanism of action of atypical antipsychotics

  • Brain injury markers (S100B and NSE) in chronic cocaine dependents.

  • Impaired hippocampal rhythmogenesis in a mouse model of mesial temporal lobe epilepsy.

  • On the formation of gamma-coherent cell assemblies by oriens lacunosum-moleculare interneurons in the hippocampus.

  • Dynamic cross-frequency couplings of local field potential oscillations in rat striatum and hippocampus during performance of a T-maze task

  • A synaptic reinforcement-based model for transient amnesia following disruptions of memory consolidation and reconsolidation.

  • Sharp edge artifacts and spurious coupling in EEG frequency comodulation measures

  • Guanosine and its modulatory effects on the glutamatergic system.

  • On the convergence of series of translated functions and applications.

  • Theta-gamma coupling increases during the learning of item-context associations.

  • The NMDA antagonist MK-801 induces hyperalgesia and increases CSF excitatory amino acids in rats: Reversal by guanosine.

  • Hippocampal theta rhythm and its coupling with gamma oscillations require fast inhibition onto parvalbumin-positive interneurons.

  • Different kinds of subjective experience during lucid dreaming may have different neural substrates

  • Oscillations trumped by behavior: a link between sensory and direct electrical stimulation of cortical activity.

  • Detecting brain waves communication

    Tort et al present a powerful framework for quantifying the level of coupling among simultaneous brain oscillations, which will help elucidating the importance of brain waves communication in cognitive processes.
  • Cortical Networks Produce Three Distinct 7-12 Hz Rhythms during Single Sensory Responses in the Awake Rat.

  • Selective Coupling between Theta Phase and Neocortical Fast Gamma Oscillations during REM-Sleep in Mice

    We analyzed temporal coupling between high-frequency oscillations and EEG theta activity (4–12 Hz) in recordings from mouse parietal neocortex. Theta was exclusively present during active wakefulness and REM-sleep. Fast oscillations occurred in two separate frequency bands: gamma (40–100 Hz) and fast gamma...
  • Electrophysiological effects of guanosine and MK-801 in a quinolinic acid-induced seizure model.

  • A mechanism for the formation of hippocampal neuronal firing patterns that represent what happens where.

    Tort and colleagues describe a mechanism underlying the emergence of hippocampal firing patterns that represent the conjunction of an item (what) and its location (where).
  • A mismatch-based model for memory reconsolidation and extinction in attractor networks

    A unified computational model based on attractor dynamics that accounts for the processes of memory reconsolidation and extinction
  • Revisiting Hebb's postulates

    A new analysis framework to address the cell assembly hypothesis at the systems level.