The hypothalamic link between arousal and sleep homeostasis in mice

Sleep and wakefulness are not simple, homogenous all-or-none states but represent a spectrum of substates, distinguished by behavior, levels of arousal, and brain activity at the local and global levels. Until now, the role of the hypothalamic circuitry in sleep–wake control was studied primarily with respect to its contribution to rapid state transitions. In contrast, whether the hypothalamus modulates within-state dynamics (state “quality”) and the functional significance thereof remains unexplored. Here, we show that photoactivation of inhibitory neurons in the lateral preoptic area (LPO) of the hypothalamus of adult male and female laboratory mice does not merely trigger awakening from sleep, but the resulting awake state is also characterized by an activated electroencephalogram (EEG) pattern, suggesting increased levels of arousal. This was associated with a faster build-up of sleep pressure, as reflected in higher EEG slow-wave activity (SWA) during subsequent sleep. In contrast, photoinhibition of inhibitory LPO neurons did not result in changes in vigilance states but was associated with persistently increased EEG SWA during spontaneous sleep. These findings suggest a role of the LPO in regulating arousal levels, which we propose as a key variable shaping the daily architecture of sleep–wake states.

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The role of the hypothalamus in cortical arousal and sleep homeostasis

10.1101/2020.05.19.104521 ◽

2020 ◽

Author(s):

Tomoko Yamagata ◽

Martin C. Kahn ◽

Merima Šabanović ◽

Mathilde C.C. Guillaumin ◽

Vincent van der Vinne ◽

...

Keyword(s):

Brain Activity ◽

Spatial Scales ◽

Inhibitory Neurons ◽

State Transitions ◽

Global State ◽

Sleep Homeostasis ◽

State Changes ◽

Temporal And Spatial ◽

Intrinsic Variable

AbstractSleep and wakefulness are not simple homogenous all-or-none states, but instead are characterized by rich dynamics of brain activity across many temporal and spatial scales. Rapid global state transitions between waking and sleeping are believed to be controlled by hypothalamic circuits, but the contribution of the hypothalamus to within-state changes of sleep and wake “intensity” remains largely unexplored. Here we show that stimulation of inhibitory neurons in the preoptic hypothalamus does not merely trigger awakening from sleep, but the resulting awake state is also characterized by increased cortical activity. This activation is associated with a faster build-up of sleep pressure, proportional to the arousal level. These findings show that hypothalamic systems thought to exclusively control global state switching, also regulate within-state “intensity”, which we propose as a key intrinsic variable in shaping the architecture of sleep/wake states across the 24h day.

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The relationship between fasting-induced torpor, sleep and waking in laboratory mice

SLEEP ◽

10.1093/sleep/zsab093 ◽

2021 ◽

Author(s):

Yi-Ge Huang ◽

Sarah J Flaherty ◽

Carina A Pothecary ◽

Russell G Foster ◽

Stuart N Peirson ◽

...

Keyword(s):

Body Temperature ◽

Rem Sleep ◽

Brain Activity ◽

Mammalian Species ◽

Nrem Sleep ◽

Laboratory Mice ◽

State Classification ◽

Metabolic Suppression ◽

The Relationship ◽

Electroencephalogram Eeg

Abstract Study objectives Torpor is a regulated and reversible state of metabolic suppression used by many mammalian species to conserve energy. Whereas the relationship between torpor and sleep has been well-studied in seasonal hibernators, less is known about the effects of fasting-induced torpor on states of vigilance and brain activity in laboratory mice. Methods Continuous monitoring of electroencephalogram (EEG), electromyogram (EMG) and surface body temperature was undertaken in adult, male C57BL/6 mice over consecutive days of scheduled restricted feeding. Results All animals showed bouts of hypothermia that became progressively deeper and longer as fasting progressed. EEG and EMG were markedly affected by hypothermia, although the typical electrophysiological signatures of NREM sleep, REM sleep and wakefulness enabled us to perform vigilance-state classification in all cases. Consistent with previous studies, hypothermic bouts were initiated from a state indistinguishable from NREM sleep, with EEG power decreasing gradually in parallel with decreasing surface body temperature. During deep hypothermia, REM sleep was largely abolished, and we observed shivering-associated intense bursts of muscle activity. Conclusions Our study highlights important similarities between EEG signatures of fasting-induced torpor in mice, daily torpor in Djungarian hamsters and hibernation in seasonally-hibernating species. Future studies are necessary to clarify the effects on fasting-induced torpor on subsequent sleep.

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Profil Electroencephalogram (EEG) Pasien Rumah Sakit Angkatan Laut Dr. Ramelan Surabaya Periode Januari 2018 sampai Desember 2018

Hang Tuah Medical journal ◽

10.30649/htmj.v16i2.157 ◽

2019 ◽

Vol 16 (2) ◽

pp. 153

Author(s):

ERIC HARTONO TEDYANTO ◽

NI KOMANG SRI DEWI UTAMI ◽

WIENTA DIASVITRI

Keyword(s):

Brain Cortex ◽

Total Population ◽

Brain Activity ◽

Descriptive Research ◽

Different Types ◽

Naval Hospital ◽

Electroencephalogram Eeg ◽

The Brain ◽

Eeg Pattern ◽

Simultaneous Activity

ABSTRAKPendahuluan: Elektroensefalogram atau rekam kelistrikkan otak adalah metode dalam neurofisiologi yang telah terbukti dapat diaplikasikan dalam ilmu kedokteran. Berbagai tipe dari ritme otak yang simultan menunjukkan bahwa aktivitas dari neuron korteks otak bergantung pada kondisi status mental seseorang. Tujuan: untuk mengetahui pola gelombang EEG pasien di RSAL dr. Ramelan Surabaya. Metode: Penelitian ini merupakan penelitian deskriptif dengan metode studi prevalensi. Teknik pengambilan sampling adalah Total Population yaitu semua pasien yang melakukan pemeriksaan EEG yang didapat dari rekam medik ruang EEG RSAL dr. Ramelan Surabaya periode Januari 2018 sampai Desember 2018 yang memenuhi kriteria inklusi dan eksklusi dari sampel. Hasil: Pasien yang paling sering melakukan pemeriksaan berdasarkan usia adalah usia balita, berdasarkan jenis kelamin adalah laki-laki, dan berdasarkan diagnosa klinis adalah konvulsif epilepsy dengan pola gelombang tersering yaitu SW.Kata kunci: elektroensefalogram, kelistrikkan otak, epilepsi.ABSTRACTIntroduction: An electroencephalogram (EEG) is an accepted method in neurophysiology with a wide application. Different types of brain rhythms indicate that simultaneous activity of the brain cortex neurons depend on the person’s mental state. Aim: to know the EEG pattern of patients at dr. Ramelan Naval Hospital Surabaya. Method: this research is a descriptive research with prevalence study method. Using total population for sampling, all patients who did the electroencephalogram examination at dr. Ramelan Naval Hospital Surabaya period January 2018 until December 2018. Result: Toddlers were the most frequently patients who did electroencephalogram examination. Based on sex, male were the most frequent. Based on clinical diagnose, patient with convulsive epilepsy are the most frequent with SW wave result.Keywords: electroencephalogram, brain activity, epilepsy.

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Modality and folk psychology

Studies in history and philosophy of science and technology ◽

10.15421/271903 ◽

2019 ◽

Vol 28 (1) ◽

pp. 19-27

Author(s):

Ja. O. Petik

Keyword(s):

Modal Logic ◽

Brain Activity ◽

Formal System ◽

Philosophy Of Logic ◽

Psychological States ◽

Formal Systems ◽

Modern Psychology ◽

Philosophical Interpretation ◽

Important Direction

The connection of the modern psychology and formal systems remains an important direction of research. This paper is centered on philosophical problems surrounding relations between mental and logic. Main attention is given to philosophy of logic but certain ideas are introduced that can be incorporated into the practical philosophical logic. The definition and properties of basic modal logic and descending ones which are used in study of mental activity are in view. The defining role of philosophical interpretation of modality for the particular formal system used for research in the field of psychological states of agents is postulated. Different semantics of modal logic are studied. The hypothesis about the connection of research in cognitive psychology (semantics of brain activity) and formal systems connected to research of psychological states is stated.

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Delta band activity contributes to the identification of command following in disorder of consciousness

Scientific Reports ◽

10.1038/s41598-021-95818-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Gonzalo Rivera-Lillo ◽

Emmanuel A. Stamatakis ◽

Tristan A. Bekinschtein ◽

David K. Menon ◽

Srivas Chennu

Keyword(s):

Functional Neuroimaging ◽

Brain Activity ◽

Disorder Of Consciousness ◽

Fine Grained ◽

Electrical Brain Activity ◽

Delta Band ◽

Delta Modulation ◽

Command Following ◽

Band Activity

AbstractThe overt or covert ability to follow commands in patients with disorders of consciousness is considered a sign of awareness and has recently been defined as cortically mediated behaviour. Despite its clinical relevance, the brain signatures of the perceptual processing supporting command following have been elusive. This multimodal study investigates the temporal spectral pattern of electrical brain activity to identify features that differentiated healthy controls from patients both able and unable to follow commands. We combined evidence from behavioural assessment, functional neuroimaging during mental imagery and high-density electroencephalography collected during auditory prediction, from 21 patients and 10 controls. We used a penalised regression model to identify command following using features from electroencephalography. We identified seven well-defined spatiotemporal signatures in the delta, theta and alpha bands that together contribute to identify DoC subjects with and without the ability to follow command, and further distinguished these groups of patients from controls. A fine-grained analysis of these seven signatures enabled us to determine that increased delta modulation at the frontal sensors was the main feature in command following patients. In contrast, higher frequency theta and alpha modulations differentiated controls from both groups of patients. Our findings highlight a key role of spatiotemporally specific delta modulation in supporting cortically mediated behaviour including the ability to follow command. However, patients able to follow commands nevertheless have marked differences in brain activity in comparison with healthy volunteers.

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Cortical and Striatal Electroencephalograms and Apomorphine Effects in the FUS Mouse Model of Amyotrophic Lateral Sclerosis

Journal of Alzheimer s Disease ◽

10.3233/jad-201472 ◽

2021 ◽

pp. 1-15

Author(s):

Vasily Vorobyov ◽

Alexander Deev ◽

Frank Sengpiel ◽

Vladimir Nebogatikov ◽

Aleksey A. Ustyugov

Keyword(s):

Amyotrophic Lateral Sclerosis ◽

Motor Neurons ◽

Cortical Neurons ◽

Primary Motor Cortex ◽

Beta Activity ◽

Systemic Injection ◽

Eeg Spectra ◽

Electroencephalogram Eeg ◽

Lateral Sclerosis

Background: Amyotrophic lateral sclerosis (ALS) is characterized by degeneration of motor neurons resulting in muscle atrophy. In contrast to the lower motor neurons, the role of upper (cortical) neurons in ALS is yet unclear. Maturation of locomotor networks is supported by dopaminergic (DA) projections from substantia nigra to the spinal cord and striatum. Objective: To examine the contribution of DA mediation in the striatum-cortex networks in ALS progression. Methods: We studied electroencephalogram (EEG) from striatal putamen (Pt) and primary motor cortex (M1) in ΔFUS(1–359)-transgenic (Tg) mice, a model of ALS. EEG from M1 and Pt were recorded in freely moving young (2-month-old) and older (5-month-old) Tg and non-transgenic (nTg) mice. EEG spectra were analyzed for 30 min before and for 60 min after systemic injection of a DA mimetic, apomorphine (APO), and saline. Results: In young Tg versus nTg mice, baseline EEG spectra in M1 were comparable, whereas in Pt, beta activity in Tg mice was enhanced. In older Tg versus nTg mice, beta dominated in EEG from both M1 and Pt, whereas theta and delta 2 activities were reduced. In younger Tg versus nTg mice, APO increased theta and decreased beta 2 predominantly in M1. In older mice, APO effects in these frequency bands were inversed and accompanied by enhanced delta 2 and attenuated alpha in Tg versus nTg mice. Conclusion: We suggest that revealed EEG modifications in ΔFUS(1–359)-transgenic mice are associated with early alterations in the striatum-cortex interrelations and DA transmission followed by adaptive intracerebral transformations.

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Endocannabinoid system in the neurodevelopment of GABAergic interneurons: implications for neurological and psychiatric disorders

Reviews in the Neurosciences ◽

10.1515/revneuro-2020-0134 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Chang-geng Song ◽

Xin Kang ◽

Fang Yang ◽

Wan-qing Du ◽

Jia-jia Zhang ◽

...

Keyword(s):

Psychiatric Disorders ◽

Endocannabinoid System ◽

Autism Spectrum ◽

Network Activity ◽

Inhibitory Neurons ◽

Gabaergic Interneurons ◽

Neural Stem Progenitor Cells ◽

The Central Nervous System ◽

Interneuron Development

Abstract In mature mammalian brains, the endocannabinoid system (ECS) plays an important role in the regulation of synaptic plasticity and the functioning of neural networks. Besides, the ECS also contributes to the neurodevelopment of the central nervous system. Due to the increase in the medical and recreational use of cannabis, it is inevitable and essential to elaborate the roles of the ECS on neurodevelopment. GABAergic interneurons represent a group of inhibitory neurons that are vital in controlling neural network activity. However, the role of the ECS in the neurodevelopment of GABAergic interneurons remains to be fully elucidated. In this review, we provide a brief introduction of the ECS and interneuron diversity. We focus on the process of interneuron development and the role of ECS in the modulation of interneuron development, from the expansion of the neural stem/progenitor cells to the migration, specification and maturation of interneurons. We further discuss the potential implications of the ECS and interneurons in the pathogenesis of neurological and psychiatric disorders, including epilepsy, schizophrenia, major depressive disorder and autism spectrum disorder.

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Possible Role of High-Dose Barbiturates and Early Administration of Parenteral Ketogenic Diet for Reducing Development of Chronic Epilepsy in Febrile Infection-Related Epilepsy Syndrome: A Case Report

Neuropediatrics ◽

10.1055/s-0040-1716903 ◽

2020 ◽

Author(s):

Shimpei Baba ◽

Tohru Okanishi ◽

Koichi Ohsugi ◽

Rika Suzumura ◽

Keiko Niimi ◽

...

Keyword(s):

Continuous Infusion ◽

Ketogenic Diet ◽

Epilepsy Syndrome ◽

High Dose ◽

Early Administration ◽

Chronic Epilepsy ◽

Time Period ◽

Irreversible Brain Damage ◽

Electroencephalogram Eeg

AbstractWe describe the efficacy of high-dose barbiturates and early administration of a parenteral ketogenic diet (KD) as initial treatments for acute status epilepticus (SE) in an 8-year-old girl with febrile infection-related epilepsy syndrome (FIRES). The patient was admitted to our hospital with refractory focal SE. Abundant epileptic discharges over the left frontal region were observed on electroencephalogram (EEG). Treatment with continuous infusion of thiamylal for 4 hours, increased incrementally to 40 mg/kg/h, successfully ended the clinical SE, and induced a burst-suppression coma. The infusion rate was then gradually decreased to 4 mg/kg/h over the next 12 hours. Parenteral KD was administered from days 6 to 21 of illness. Continuous infusion of thiamylal was switched to midazolam on day 10 without causing seizures or EEG exacerbations. The patient has remained seizure free in the 15 months since hospital discharge. The effectiveness of KD for the treatment of FIRES has attracted attention amongst clinicians, but KD treatment may need to last for 2 to 4 days before it can stop SE, a time period that could cause irreversible brain damage. Considering the severity of SE in our patient and the dose of barbiturates needed to treat it, we consider this case to have had a good clinical outcome. The results suggest that rapid termination of seizure using high-dose barbiturates in conjunction with early administration of parenteral KD could reduce the development of chronic epilepsy in patients with FIRES.

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Consciousness, decision making, and volition: freedom beyond chance and necessity

Theory in Biosciences ◽

10.1007/s12064-021-00346-6 ◽

2021 ◽

Author(s):

Hans Liljenström

Keyword(s):

Decision Making ◽

Free Will ◽

Brain Activity ◽

Brain Structures ◽

Complex Process ◽

Neural Information ◽

Neural Information Processing ◽

Stochastic Population Model ◽

The Brain

AbstractWhat is the role of consciousness in volition and decision-making? Are our actions fully determined by brain activity preceding our decisions to act, or can consciousness instead affect the brain activity leading to action? This has been much debated in philosophy, but also in science since the famous experiments by Libet in the 1980s, where the current most common interpretation is that conscious free will is an illusion. It seems that the brain knows, up to several seconds in advance what “you” decide to do. These studies have, however, been criticized, and alternative interpretations of the experiments can be given, some of which are discussed in this paper. In an attempt to elucidate the processes involved in decision-making (DM), as an essential part of volition, we have developed a computational model of relevant brain structures and their neurodynamics. While DM is a complex process, we have particularly focused on the amygdala and orbitofrontal cortex (OFC) for its emotional, and the lateral prefrontal cortex (LPFC) for its cognitive aspects. In this paper, we present a stochastic population model representing the neural information processing of DM. Simulation results seem to confirm the notion that if decisions have to be made fast, emotional processes and aspects dominate, while rational processes are more time consuming and may result in a delayed decision. Finally, some limitations of current science and computational modeling will be discussed, hinting at a future development of science, where consciousness and free will may add to chance and necessity as explanation for what happens in the world.

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