Comparative Analysis of Methods for Estimation of Undirected Coupling from Time Series of Intracranial Eegs of Cortex of Rats-Genetic Models of Absence Epilepsy

Studying coupling between brain areas from its electromagnetic activity is one of the key approaches in epilepsy research now, since epileptic activity has been considered to be a result of pathological synchronization in the brain. Often, research is conducted on animal models, because this allows to perform intracranial measurement, and to get rid of interference caused by the skull and to receive signals from deeper regions of the brain such as thalamus or hippocampus. In this study, the intracranial recordings from the frontal and parietal areas of cortex are investigated with a nonlinear correlation coefficient and a mutual information function in a sliding time window. The coupling estimates obtained were subjected for statistical analysis for significance using surrogate data. The dynamics of connectivity between the frontal cortex and the parietal cortex was shown to vary from seizure to seizure and from animal to animal. Therefore, estimates of the significant change in connectivity associated with initiation of the absense seizure, found previously based on averaging over a large number of animals and a large number of seizures for an each animal, can be a result of contribution of a relatively small number of seizures (less than a half of considered), for which the changes are significant.

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Collective excitability in a mesoscopic neuronal model of epileptic activity

10.1101/162636 ◽

2017 ◽

Cited By ~ 1

Author(s):

Maciej Jedynak ◽

Antonio J. Pons ◽

Jordi Garcia-Ojalvo

Keyword(s):

Neuronal Model ◽

Epileptic Activity ◽

Brain Areas ◽

Sustained Activity ◽

Collective Activity ◽

Neural Mass ◽

Joint Dynamics ◽

Coupling Strengths ◽

Neuronal Oscillators ◽

The Brain

The brain can be understood as a collection of interacting neuronal oscillators, but the extent to which its sustained activity is due to coupling among brain areas is still unclear. Here we study the joint dynamics of two cortical columns described by Jansen-Rit neural mass models, and show that coupling between the columns gives rise to stochastic initiations of sustained collective activity, which can be interpreted as epileptic events. For large enough coupling strengths, termination of these events results mainly from the emergence of synchronization between the columns, and thus is controlled by coupling instead of noise. Stochastic triggering and noise-independent durations are characteristic of excitable dynamics, and thus we interpret our results in terms of collective excitability.

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Perceptual inference employs intrinsic alpha frequency to resolve perceptual ambiguity

10.1101/399840 ◽

2018 ◽

Author(s):

Lu Shen ◽

Biao Han ◽

Lihan Chen ◽

Qi Chen

Keyword(s):

Time Window ◽

Inference Process ◽

Perceptual Inference ◽

Band Frequency ◽

Sensory Inputs ◽

Alpha Frequency ◽

Neural Representations ◽

Intracranial Recordings ◽

Time Information ◽

The Brain

AbstractThe brain uses its intrinsic dynamics to actively predict observed sensory inputs, especially under perceptual ambiguity. However, it remains unclear how this inference process is neurally implemented in biasing perception of ambiguous inputs towards the predicted percepts. Using electroencephalography and intracranial recordings, we first show that the alpha-band frequency defines a unified time window for perceptual grouping across both space and time: information segments, either spatially or temporally segregated, will be integrated if they fall within the same alpha cycle. Moreover, predictions employ this prior knowledge on intrinsic alpha frequency to shift perceptual inference towards the most possibly observed percepts. Multivariate decoding analysis showed that perceptual inference, based on variance in prestimulus alpha frequency (PAF), biases post-stimulus neural representations by inducing preactivation of the predicted percepts. fMRI results additionally showed that prestimulus activity and intrinsic organization status in the frontoparietal attentional network predict perceptual outcomes, probably by modulating occipitoparietal PAFs.

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Aetiologies and anatomy of confabulation

10.1093/oso/9780198789680.003.0004 ◽

2017 ◽

Author(s):

Armin Schnider

Keyword(s):

Brain Damage ◽

Limbic Encephalitis ◽

Artery Aneurysm ◽

Anterior Communicating Artery ◽

Brain Areas ◽

Anatomical Basis ◽

Korsakoff Syndrome ◽

Hypoxic Brain ◽

Degenerative Dementia ◽

The Brain

What diseases cause confabulations and which are the brain areas whose damage is responsible? This chapter reviews the causes, both historic and present, of confabulations and deduces the anatomo-clinical relationships for the four forms of confabulation in the following disorders: alcoholic Korsakoff syndrome, traumatic brain injury, rupture of an anterior communicating artery aneurysm, posterior circulation stroke, herpes and limbic encephalitis, hypoxic brain damage, degenerative dementia, tumours, schizophrenia, and syphilis. Overall, clinically relevant confabulation is rare. Some aetiologies have become more important over time, others have virtually disappeared. While confabulations seem to be more frequent after anterior brain damage, only one form has a distinct anatomical basis.

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Limbic Expression of mRNA Coding for Chemoreceptors in Human Brain—Lessons from Brain Atlases

International Journal of Molecular Sciences ◽

10.3390/ijms22136858 ◽

2021 ◽

Vol 22 (13) ◽

pp. 6858

Author(s):

Fanny Gaudel ◽

Gaëlle Guiraudie-Capraz ◽

François Féron

Keyword(s):

G Proteins ◽

The Body ◽

Trace Amines ◽

Chemical Senses ◽

Brain Areas ◽

Genes Encoding ◽

The Central Nervous System ◽

Human Brains ◽

The Brain ◽

Brain Atlases

Animals strongly rely on chemical senses to uncover the outside world and adjust their behaviour. Chemical signals are perceived by facial sensitive chemosensors that can be clustered into three families, namely the gustatory (TASR), olfactory (OR, TAAR) and pheromonal (VNR, FPR) receptors. Over recent decades, chemoreceptors were identified in non-facial parts of the body, including the brain. In order to map chemoreceptors within the encephalon, we performed a study based on four brain atlases. The transcript expression of selected members of the three chemoreceptor families and their canonical partners was analysed in major areas of healthy and demented human brains. Genes encoding all studied chemoreceptors are transcribed in the central nervous system, particularly in the limbic system. RNA of their canonical transduction partners (G proteins, ion channels) are also observed in all studied brain areas, reinforcing the suggestion that cerebral chemoreceptors are functional. In addition, we noticed that: (i) bitterness-associated receptors display an enriched expression, (ii) the brain is equipped to sense trace amines and pheromonal cues and (iii) chemoreceptor RNA expression varies with age, but not dementia or brain trauma. Extensive studies are now required to further understand how the brain makes sense of endogenous chemicals.

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Initiators of Classical and Lectin Complement Pathways Are Differently Engaged after Traumatic Brain Injury—Time-Dependent Changes in the Cortex, Striatum, Thalamus and Hippocampus in a Mouse Model

International Journal of Molecular Sciences ◽

10.3390/ijms22010045 ◽

2020 ◽

Vol 22 (1) ◽

pp. 45

Author(s):

Agata Ciechanowska ◽

Katarzyna Ciapała ◽

Katarzyna Pawlik ◽

Marco Oggioni ◽

Domenico Mercurio ◽

...

Keyword(s):

Brain Injury ◽

Microglial Cell ◽

Lectin Pathway ◽

Brain Areas ◽

Mannose Binding ◽

Primary Microglial Cell ◽

Cellular Markers ◽

The Brain ◽

Binding Lectin ◽

Complement Pathways

The complement system is involved in promoting secondary injury after traumatic brain injury (TBI), but the roles of the classical and lectin pathways leading to complement activation need to be clarified. To this end, we aimed to determine the ability of the brain to activate the synthesis of classical and lectin pathway initiators in response to TBI and to examine their expression in primary microglial cell cultures. We have modeled TBI in mice by controlled cortical impact (CCI), a clinically relevant experimental model. Using Real-time quantitative polymerase chain reaction (RT-qPCR) we analyzed the expression of initiators of classical the complement component 1q, 1r and 1s (C1q, C1r, and C1s) and lectin (mannose binding lectin A, mannose binding lectin C, collectin 11, ficolin A, and ficolin B) complement pathways and other cellular markers in four brain areas (cortex, striatum, thalamus and hippocampus) of mice exposed to CCI from 24 h and up to 5 weeks. In all murine ipsilateral brain structures assessed, we detected long-lasting, time- and area-dependent significant increases in the mRNA levels of all classical (C1q, C1s, C1r) and some lectin (collectin 11, ficolin A, ficolin B) initiator molecules after TBI. In parallel, we observed significantly enhanced expression of cellular markers for neutrophils (Cd177), T cells (Cd8), astrocytes (glial fibrillary acidic protein—GFAP), microglia/macrophages (allograft inflammatory factor 1—IBA-1), and microglia (transmembrane protein 119—TMEM119); moreover, we detected astrocytes (GFAP) and microglia/macrophages (IBA-1) protein level strong upregulation in all analyzed brain areas. Further, the results obtained in primary microglial cell cultures suggested that these cells may be largely responsible for the biosynthesis of classical pathway initiators. However, microglia are unlikely to be responsible for the production of the lectin pathway initiators. Immunofluorescence analysis confirmed that at the site of brain injury, the C1q is localized in microglia/macrophages and neurons but not in astroglial cells. In sum, the brain strongly reacts to TBI by activating the local synthesis of classical and lectin complement pathway activators. Thus, the brain responds to TBI with a strong, widespread and persistent upregulation of complement components, the targeting of which may provide protection in TBI.

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Ibudilast, a neuroimmune modulator, reduces heavy drinking and alcohol cue-elicited neural activation: a randomized trial

Translational Psychiatry ◽

10.1038/s41398-021-01478-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Erica N. Grodin ◽

Spencer Bujarski ◽

Brandon Towns ◽

Elizabeth Burnette ◽

Steven Nieto ◽

...

Keyword(s):

Macrophage Migration Inhibitory Factor ◽

Alcohol Use Disorder ◽

Cue Reactivity ◽

Negative Mood ◽

Heavy Drinking ◽

Neural Activation ◽

Daily Diary Study ◽

Alcohol Cues ◽

To Receive ◽

The Brain

AbstractIbudilast, a neuroimmune modulator which selectively inhibits phosphodiesterases (PDE)-3, -4, -10, and -11, and macrophage migration inhibitory factor (MIF), shows promise as a novel pharmacotherapy for alcohol use disorder (AUD). However, the mechanisms of action underlying ibudilast’s effects on the human brain remain largely unknown. Thus, the current study examined the efficacy of ibudilast to improve negative mood, reduce heavy drinking, and attenuate neural reward signals in individuals with AUD. Fifty-two nontreatment-seeking individuals with AUD were randomized to receive ibudilast (n = 24) or placebo (n = 28). Participants completed a 2-week daily diary study during which they filled out daily reports of their past day drinking, mood, and craving. Participants completed an functional magnetic resonance imaging (fMRI) alcohol cue-reactivity paradigm half-way through the study. Ibudilast did not have a significant effect on negative mood (β = −0.34, p = 0.62). However, ibudilast, relative to placebo, reduced the odds of heavy drinking across time by 45% (OR = 0.55, (95% CI: 0.30, 0.98)). Ibudilast also attenuated alcohol cue-elicited activation in the ventral striatum (VS) compared to placebo (F(1,44) = 7.36, p = 0.01). Alcohol cue-elicited activation in the VS predicted subsequent drinking in the ibudilast group (F(1,44) = 6.39, p = 0.02), such that individuals who had attenuated ventral striatal activation and took ibudilast had the fewest number of drinks per drinking day in the week following the scan. These findings extend preclinical and human laboratory studies of the utility of ibudilast to treat AUD and suggest a biobehavioral mechanism through which ibudilast acts, namely, by reducing the rewarding response to alcohol cues in the brain leading to a reduction in heavy drinking.

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Effects of the SNAP25 on Integration Ability of Brain Functions in Children With ADHD

Journal of Attention Disorders ◽

10.1177/1087054720964561 ◽

2020 ◽

pp. 108705472096456

Author(s):

Yue Yang ◽

Gang Peng ◽

Hongwu Zeng ◽

Diangang Fang ◽

Linlin Zhang ◽

...

Keyword(s):

Time Window ◽

Precentral Gyrus ◽

Children With Adhd ◽

Brain Functions ◽

Lingual Gyrus ◽

Window Method ◽

Central Gyrus ◽

The Right ◽

The Brain ◽

Insight Into

Objective: The present study aimed to examine the effects of SNAP25 on the integration ability of intrinsic brain functions in children with ADHD, and whether the integration ability was associated with working memory (WM). Methods: A sliding time window method was used to calculate the spatial and temporal concordance among five rs-fMRI regional indices in 55 children with ADHD and 20 healthy controls. Results: The SNAP25 exhibited significant interaction effects with ADHD diagnosis on the voxel-wise concordance in the right posterior central gyrus, fusiform gyrus and lingual gyrus. Specifically, for children with ADHD, G-carriers showed increased voxel-wise concordance in comparison to TT homozygotes in the right precentral gyrus, superior frontal gyrus, postcentral gyrus, and middle frontal gyrus. The voxel-wise concordance was also found to be related to WM. Conclusion: Our findings provided a new insight into the neural mechanisms of the brain function of ADHD children.

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Effect of Subarachnoid Bupivacaine Block on Anesthetic Requirements for Thiopental in Rats

Anesthesiology ◽

10.1097/00000542-199804000-00024 ◽

1998 ◽

Vol 88 (4) ◽

pp. 1036-1042 ◽

Cited By ~ 33

Author(s):

Sunil Eappen ◽

Igor Kissin

Keyword(s):

Local Anesthetic ◽

Direct Action ◽

Afferent Input ◽

Crossover Design ◽

Hemodynamic Parameters ◽

Motor Responses ◽

Withdrawal Reflex ◽

Corneal Reflex ◽

To Receive ◽

The Brain

Background Subarachnoid bupivacaine blockade has been reported to reduce thiopental and midazolam hypnotic requirements in patients. The purpose of this study was to examine if local anesthetically induced lumbar intrathecal blockade would reduce thiopental requirements for blockade of motor responses to noxious and nonnoxious stimuli in rats. Methods After intrathecal and external jugular catheter placement, rats were assigned randomly to two groups in a crossover design study, with each rat to receive either 10 microl of 0.75% bupivacaine or 10 microl of normal saline intrathecally. The doses of intravenously administered thiopental required to ablate the eyelid reflex, to block the withdrawal reflex of a front limb digit, and to block the corneal reflex were compared. In two separate groups of animals, hemodynamic parameters and concentrations of thiopental in the brain were compared between intrathecally administered bupivacaine and saline. Results The thiopental dose required to block the described responses was decreased with intrathecally administered bupivacaine versus intrathecally administered saline from (mean +/- SD) 40 +/- 5 to 24 +/- 4 mg/kg (P < 0.001) for the eyelid reflex, from 51 +/- 6 to 29 +/- 6 mg/kg (P < 0.005) for front limb withdrawal, and from 67 +/- 8 to 46 +/- 8 mg/kg (P < 0.01) for the corneal reflex. The concentration of thiopental in the brain at the time of corneal reflex blockade for the group given bupivacaine was significantly lower than in the group given saline (24.1 vs. 35.8 microg/g, P = 0.02). Conclusion This study demonstrates that lumbar intrathecally administered local anesthetic blockade decreases anesthetic requirements for thiopental for a spectrum of end points tested. This effect is due neither to altered pharmacokinetics nor to a direct action of the local anesthetic on the brain; rather, it is most likely due to decreased afferent input.

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Comparing the brain areas supporting nondeclarative categorization and recognition memory

Cognitive Brain Research ◽

10.1016/s0926-6410(02)00122-2 ◽

2002 ◽

Vol 14 (2) ◽

pp. 245-257 ◽

Cited By ~ 25

Author(s):

Paul J Reber ◽

Eric C Wong ◽

Richard B Buxton

Keyword(s):

Recognition Memory ◽

Brain Areas ◽

The Brain

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Cannabidiol Has a Unique Effect on Global Brain Activity: A Pharmacological, Functional MRI Study in Awake Mice

10.21203/rs.3.rs-253550/v1 ◽

2021 ◽

Author(s):

Aymen Sadaka ◽

Ana Ozuna ◽

Richard Ortiz ◽

Praveen Kulkarni ◽

Clare Johnson ◽

...

Keyword(s):

Prefrontal Cortex ◽

Brain Activity ◽

Stress Disorders ◽

Functional Coupling ◽

Specific Information ◽

Imaging Data ◽

Post Traumatic Stress ◽

Brain Areas ◽

Dose Dependent ◽

The Brain

Abstract Background: The phytocannabinoid cannabidiol (CBD) is a potential treatment for post-traumatic stress disorders. How does CBD interact with the brain to alter behavior? We hypothesized that CBD would produce a dose-dependent reduction in brain activity and functional coupling in neural circuitry associated with fear and defense. Methods: During the scanning session awake mice were given vehicle or CBD (3, 10, or 30 mg/kg I.P.) and imaged for 10 min post treatment. Mice were also treated with the 10 mg/kg dose of CBD and imaged one hr later for resting state BOLD functional connectivity (rsFC). Imaging data were registered to a 3D MRI mouse atlas providing site-specific information on 138 different brain areas. Blood samples were collected for CBD measurements.Results: CBD produced a dose-dependent polarization of activation along the rostral-caudal axis of the brain. The olfactory bulb and prefrontal cortex showed an increase in positive BOLD whereas the brainstem and cerebellum showed a decrease in BOLD signal. This negative BOLD affected many areas connected to the ascending reticular activating system (ARAS). The ARAS was decoupled to much of the brain but was hyperconnected to the olfactory system and prefrontal cortex. The pattern of ARAS connectivity closely overlapped with brain areas showing high levels N-acyl-phosphatidylethanolamines-specific phospholipase D (NAPE-PLD) messenger RNA.Conclusion: The CBD-induced decrease in ARAS activity is consistent with an emerging literature suggesting that CBD reduces autonomic arousal under conditions of emotional and physical stress. The putative target and mechanism of action is NAPE-PLD the enzyme responsible for the biosynthesis of lipid signaling molecules like anandamide.

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