scholarly journals 40 Hz acoustic stimulation decreases amyloid beta and modulates brain rhythms in a mouse model of Alzheimer’s disease

2018 ◽  
Author(s):  
Juho Lee ◽  
Seungjun Ryu ◽  
Hyun-Ju Kim ◽  
Jieun Jung ◽  
Boreom Lee ◽  
...  
Keyword(s):  
Mouse Model ◽  
Therapeutic Potential ◽  
Phase Locking ◽  
Acoustic Stimulation ◽  
Gamma Power ◽  
Frequency Coupling ◽  
Phase Locking Value ◽  
Gamma Band Oscillations ◽  
Cross Frequency Coupling ◽  
The Brain

AbstractIntroductionThe accumulation of amyloid-beta (Aβ) is one of the neuropathologic hallmarks of Alzheimer’s disease (AD) and abnormal gamma band oscillations and brain connectivity have been observed. Recently, a therapeutic potential of gamma entrainment of the brain was reported by Iaccarino et al. However, the affected areas were limited to hippocampus and visual cortex. Therefore, we sought to test the effects of acoustic stimulation in a mouse model of AD.MethodsFreely moving 6-month-old 5XFAD mice with electroencephalogram (EEG) electrodes were treated with daily two-hour acoustic stimulation at 40Hz for 2 weeks. Aβ and microglia were evaluated by immunohistochemistry and ELISA. Evoked and spontaneous gamma power were analyzed by wavelet analysis. Coherence, phase locking value (PLV), and cross-frequency coupling were analyzed.ResultsThe number of Aβ plaques decreased in the pre-and infralimbic (PIL) and hippocampus regions and soluble Aβ-40 and Aβ-42 peptides in PIL in the acoustic stimulation group. We also found that the number of microglia increased in PIL and hippocampus. In EEG analysis, evoked gamma power was decreased and spontaneous gamma power was increased. Gamma coherence and phase locking value did not show significant changes. Cross-frequency coupling was shifted from gamma-delta to gamma-theta rhythm.ConclusionIn summary, we found that acoustic stimulation at 40Hz can reduce Aβ in the brain and restore the gamma band oscillations and the frontoparietal connectivity. Our data suggest that acoustic stimulation might alter the natural deterioration processes of AD and have a therapeutic potential in AD.

scholarly journals Paleo-oscillomics: inferring aspects of Neanderthal language abilities from gene regulation of neural oscillations

2017 ◽  
Author(s):  
Elliot Murphy ◽  
Antonio Benítez-Burraco
Keyword(s):  
Language Evolution ◽  
Oscillatory Activity ◽  
Neural Oscillations ◽  
Brain Anatomy ◽  
Language Abilities ◽  
Frequency Coupling ◽  
Methylation Patterns ◽  
Cross Frequency Coupling ◽  
The Brain ◽  
Core Features

AbstractLanguage seemingly evolved from changes in brain anatomy and wiring. We argue that language evolution can be better understood if particular changes in phasal and cross-frequency coupling properties of neural oscillations, resulting in core features of language, are considered. Because we cannot track the oscillatory activity of the brain from extinct hominins, we used our current understanding of the language oscillogenome (that is, the set of genes responsible for basic aspects of the oscillatory activity relevant for language) to infer some properties of the Neanderthal oscillome. We have found that several candidates for the language oscillogenome show differences in their methylation patterns between Neanderthals and humans. We argue that differences in their expression levels could be informative of differences in cognitive functions important for language.

scholarly journals Effects of Transcranial Ultrasound Stimulation Pulsed at 40 Hz on Aβ Plaques and Brain Rhythms in 5XFAD Mice

2021 ◽  
Author(s):  
Mincheol Park ◽  
Gia Minh Hoang ◽  
Thien Nguyen ◽  
Eunkyung Lee ◽  
Hyun Jin Jung ◽  
...  
Keyword(s):  
Treatment Group ◽  
Mouse Model ◽  
Brain Connectivity ◽  
Transcranial Ultrasound ◽  
Sham Treatment ◽  
Ultrasound Stimulation ◽  
Gamma Power ◽  
5Xfad Mice ◽  
The Brain ◽  
Ad Mouse Model

Abstract BackgroundAlzheimer’s disease (AD) is the most common cause of dementia characterized by amyloid-β (Aβ) plaques and tauopathy. Reducing Aβ has been considered a major AD treatment strategy in pharmacological and non-pharmacological treatments. The impairment in the gamma oscillations, which play an important role in perception and cognitive function, has been shown in mouse AD models and human patients. Recently the therapeutic effect of gamma entrainment treatment on the AD mouse model was reported. Given that ultrasound is an emerging modality of neuromodulation, we investigated the effect of ultrasound stimulation pulsed at gamma frequency (40Hz) on an AD mouse model. MethodsWe implanted electroencephalogram (EEG) electrodes and a piezo-ceramic disc ultrasound transducer on the skull surface of 6-months-old 5XFAD and wild-type control mice (n=12 and 6, respectively). Six 5XFAD mice were treated with daily two-hour ultrasound stimulation at 40Hz for two weeks, and the other six mice received sham treatment. Soluble and insoluble Aβ levels in the brain were measured by enzyme-linked immunosorbent assay. Spontaneous EEG gamma power was computed by wavelet analysis, and the brain connectivity was examined with phase-locking value and cross-frequency phase-amplitude coupling. ResultsWe found that total Aβ 42 and 40 levels, especially insoluble, in the treatment group decreased compared to that of the sham treatment group. The reduction in the number of Aβ plaques in PIL also has been shown. In addition, spontaneous gamma power was increased, and brain connectivity was improved. ConclusionsThese results suggest that the transcranial ultrasound-based gamma-band entrainment technique can be an effective therapy for AD by reducing the Aβ load and improving brain connectivity

scholarly journals A Novel Anti-Inflammatory d-Peptide Inhibits Disease Phenotype Progression in an ALS Mouse Model

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1590
Author(s):  
Julia Post ◽  
Vanessa Kogel ◽  
Anja Schaffrath ◽  
Philipp Lohmann ◽  
Nadim Joni Shah ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Mouse Model ◽  
Brain Stem ◽  
Motor Coordination ◽  
Therapeutic Potential ◽  
Lumbar Spinal Cord ◽  
Motor Deficits ◽  
Disease Phenotype ◽  
Lumbar Spinal ◽  
The Brain

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease characterised by selective neuronal death in the brain stem and spinal cord. The cause is unknown, but an increasing amount of evidence has firmly certified that neuroinflammation plays a key role in ALS pathogenesis. Neuroinflammation is a pathological hallmark of several neurodegenerative disorders and has been implicated as driver of disease progression. Here, we describe a treatment study demonstrating the therapeutic potential of a tandem version of the well-known all-d-peptide RD2 (RD2RD2) in a transgenic mouse model of ALS (SOD1*G93A). Mice were treated intraperitoneally for four weeks with RD2RD2 vs. placebo. SOD1*G93A mice were tested longitudinally during treatment in various behavioural and motor coordination tests. Brain and spinal cord samples were investigated immunohistochemically for gliosis and neurodegeneration. RD2RD2 treatment in SOD1*G93A mice resulted not only in a reduction of activated astrocytes and microglia in both the brain stem and lumbar spinal cord, but also in a rescue of neurons in the motor cortex. RD2RD2 treatment was able to slow progression of the disease phenotype, especially the motor deficits, to an extent that during the four weeks treatment duration, no significant progression was observed in any of the motor experiments. Based on the presented results, we conclude that RD2RD2 is a potential therapeutic candidate against ALS.

scholarly journals Intravenous infusion of iPSC-derived neural precursor cells increases acid β-glucosidase function in the brain and lessens the neuronopathic phenotype in a mouse model of Gaucher disease

2019 ◽  
Vol 28 (20) ◽  
pp. 3406-3421 ◽  
Author(s):  
Yanyan Peng ◽  
Benjamin Liou ◽  
Venette Inskeep ◽  
Rachel Blackwood ◽  
Christopher N Mayhew ◽  
...  
Keyword(s):  
Mouse Model ◽  
Gaucher Disease ◽  
Fluorescent Protein ◽  
Therapeutic Potential ◽  
Wild Type Mouse ◽  
Induced Pluripotent Stem Cell ◽  
Precursor Cells ◽  
Mrna Levels ◽  
Green Fluorescent ◽  
The Brain

Abstract Gaucher disease (GD) is caused by GBA1 mutations leading to functional deficiency of acid-β-glucosidase (GCase). No effective treatment is available for neuronopathic GD (nGD). A subclass of neural stem and precursor cells (NPCs) expresses VLA4 (integrin α4β1, very late antigen-4) that facilitates NPC entry into the brain following intravenous (IV) infusion. Here, the therapeutic potential of IV VLA4+NPCs was assessed for nGD using wild-type mouse green fluorescent protein (GFP)-positive multipotent induced pluripotent stem cell (iPSC)-derived VLA4+NPCs. VLA4+NPCs successfully engrafted in the nGD (4L;C*) mouse brain. GFP-positive cells differentiated into neurons, astrocytes and oligodendrocytes in the brainstem, midbrain and thalamus of the transplanted mice and significantly improved sensorimotor function and prolonged life span compared to vehicle-treated 4L;C* mice. VLA4+NPC transplantation significantly decreased levels of CD68 and glial fibrillary acidic protein, as well as TNFα mRNA levels in the brain, indicating reduced neuroinflammation. Furthermore, decreased Fluoro-Jade C and NeuroSilver staining suggested inhibition of neurodegeneration. VLA4+NPC-engrafted 4L;C* midbrains showed 35% increased GCase activity, reduced substrate [glucosylceramide (GC, −34%) and glucosylsphingosine (GS, −11%)] levels and improved mitochondrial oxygen consumption rates in comparison to vehicle-4L;C* mice. VLA4+NPC engraftment in 4L;C* brain also led to enhanced expression of neurotrophic factors that have roles in neuronal survival and the promotion of neurogenesis. This study provides evidence that iPSC-derived NPC transplantation has efficacy in an nGD mouse model and provides proof of concept for autologous NPC therapy in nGD.

scholarly journals From thoughtless awareness to effortful cognition: alpha - theta cross-frequency dynamics in experienced meditators during meditation, rest and arithmetic

2020 ◽  
Author(s):  
Julio Rodriguez-Larios ◽  
Pascal Faber ◽  
Peter Achermann ◽  
Shisei Tei ◽  
Kaat Alaerts
Keyword(s):  
Cognitive Processing ◽  
Information Integration ◽  
Recent Theory ◽  
Harmonic Frequency ◽  
Arithmetic Task ◽  
Continuous Eeg ◽  
Frequency Coupling ◽  
Eeg Recordings ◽  
Cross Frequency Coupling ◽  
The Brain

AbstractNeural activity is known to oscillate within discrete frequency bands and the synchronization between these rhythms is hypothesized to underlie information integration in the brain. Since strict synchronization is only possible for harmonic frequencies, a recent theory proposes that the interaction between different brain rhythms is facilitated by transient harmonic frequency arrangements. In this line, it has been recently shown that the transient occurrence of 2:1 harmonic cross-frequency relationships between alpha and theta rhythms (i.e. falpha≈12 Hz; ftheta≈6 Hz) is enhanced during effortful cognition. In this study, we tested whether achieving a state of ‘mental emptiness’ during meditation is accompanied by a relative decrease in the occurrence of 2:1 harmonic cross-frequency relationships between alpha and theta rhythms. Continuous EEG recordings (19 electrodes) were obtained from 43 highly experienced meditators during meditation practice, rest and an arithmetic task. We show that the occurrence of transient alpha:theta 2:1 harmonic relationships increased linearly from a meditative to an active cognitive processing state (i.e. meditation< rest< arithmetic task). It is argued that transient EEG cross-frequency arrangements that prevent alpha:theta cross-frequency coupling could facilitate the experience of ‘mental emptiness’ by avoiding the interaction between the memory and executive components of cognition.

scholarly journals Cross frequency coupling in next generation inhibitory neural mass models

2019 ◽  
Author(s):  
Andrea Ceni ◽  
Simona Olmi ◽  
Alessandro Torcini ◽  
David Angulo-Garcia
Keyword(s):  
Information Processing ◽  
Cognitive Processes ◽  
Neural Mass Model ◽  
Neural Population ◽  
Mass Model ◽  
Collective Behaviors ◽  
Neural Mass ◽  
Frequency Coupling ◽  
Cross Frequency Coupling ◽  
The Brain

Coupling among neural rhythms is one of the most important mechanisms at the basis of cognitive processes in the brain. In this study we consider a neural mass model, rigorously obtained from the microscopic dynamics of an inhibitory spiking network with exponential synapses, able to autonomously generate collective oscillations (COs). These oscillations emerge via a super-critical Hopf bifurcation, and their frequencies are controlled by the synaptic time scale, the synaptic coupling and the excitability of the neural population. Furthermore, we show that two inhibitory populations in a master-slave configuration with different synaptic time scales can display various collective dynamical regimes: namely, damped oscillations towards a stable focus, periodic and quasi-periodic oscillations, and chaos. Finally, when bidirectionally coupled the two inhibitory populations can exhibit different types of θ-γ cross-frequency couplings (CFCs): namely, phase-phase and phase-amplitude CFC. The coupling between θ and γ COs is enhanced in presence of a external θ forcing, reminiscent of the type of modulation induced in Hippocampal and Cortex circuits via optogenetic drive.In healthy conditions, the brain’s activity reveals a series of intermingled oscillations, generated by large ensembles of neurons, which provide a functional substrate for information processing. How single neuron properties influence neuronal population dynamics is an unsolved question, whose solution could help in the understanding of the emergent collective behaviors arising during cognitive processes. Here we consider a neural mass model, which reproduces exactly the macroscopic activity of a network of spiking neurons. This mean-field model is employed to shade some light on an important and ubiquitous neural mechanism underlying information processing in the brain: the θ-γ cross-frequency coupling. In particular, we will explore in detail the conditions under which two coupled inhibitory neural populations can generate these functionally relevant coupled rhythms.

Introduction to Electroencephalography

2019 ◽  
pp. 35-46 ◽  
Author(s):  
Michael Avidan ◽  
Jamie Sleigh
Keyword(s):  
Monitoring Method ◽  
Spectral Edge Frequency ◽  
Non Invasive ◽  
Eeg Changes ◽  
Frequency Coupling ◽  
Cross Frequency Coupling ◽  
Electroencephalogram Eeg ◽  
The Brain ◽  
Nmda Blockers ◽  
Induction Agents

This chapter presents an introduction to electroencephalography, a non-invasive electrophysiological monitoring method to record electrical activity of the brain. It discusses waveforms in the electroencephalogram (EEG), and EEG changes with general anaesthesia. It covers EEG neurobiology, effects of different drugs (e.g., opioids, NMDA blockers, GABAergic intravenous induction agents, hydrocarbon-based volatile anaesthetic drugs), EEG changes as a function of patients’ age, and the titration of anaesthesia. It also covers special concepts in anaesthetic monitoring, including power spectrum, spectral edge frequency, spectrogram, cross frequency coupling and coherence, proprietary pEEG indices, EEG measures of connectivity, and artefacts. Finally, it discusses future directions within the specialty.

scholarly journals An oscillator ensemble model of sequence learning

2019 ◽  
Author(s):  
Alexander Maye ◽  
Peng Wang ◽  
Jonathan Daume ◽  
Xiaolin Hu ◽  
Andreas K. Engel
Keyword(s):  
Brain Activity ◽  
Phase Locking ◽  
Electrophysiological Recordings ◽  
Sequence Elements ◽  
Synchronization Phase ◽  
Frequency Coupling ◽  
Human Participants ◽  
The Individual ◽  
Cross Frequency Coupling ◽  
Good Agreement

AbstractLearning and memorizing sequences of events is an important function of the human brain and the basis for forming expectations and making predictions. Learning is facilitated by repeating a sequence several times, causing rhythmic appearance of the individual sequence elements. This observation invites to consider the resulting multitude of rhythms as a spectral ‘fingerprint’ which characterizes the respective sequence. Here we explore the implications of this perspective by developing a neurobiologically plausible computational model which captures this ‘fingerprint’ by attuning an ensemble of neural oscillators. In our model, this attuning process is based on a number of oscillatory phenomena that have been observed in electrophysiological recordings of brain activity like synchronization, phase locking and reset as well as cross-frequency coupling. We compare the learning properties of the model with behavioral results from a study in human participants and observe good agreement of the errors for different levels of complexity of the sequence to be memorized. Finally, we suggest an extension of the model for processing sequences that extend over several sensory modalities.

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