scholarly journals A literature-based meta-analysis of brain-wide electrophysiological diversity

2015 ◽  
Author(s):  
Shreejoy J Tripathy ◽  
Shawn D Burton ◽  
Matthew Geramita ◽  
Richard C Gerkin ◽  
Nathaniel N Urban
Keyword(s):  
Meta Analysis ◽  
Study Data ◽  
Neuronal Diversity ◽  
Biophysical Properties ◽  
Experimental Conditions ◽  
Electrophysiological Properties ◽  
Rich Diversity ◽  
Fast Spiking ◽  
The Brain ◽  
Substantial Degree

For decades, neurophysiologists have characterized the biophysical properties of a rich diversity of neuron types. However, identifying common features and computational roles shared across neuron types is made more difficult by inconsistent conventions for collecting and reporting biophysical data. Here, we leverage NeuroElectro, a literature-based database of electrophysiological properties (www.neuroelectro.org), to better understand neuronal diversity -- both within and across neuron types -- and the confounding influences of methodological variability. We show that experimental conditions (e.g., electrode types, recording temperatures, or animal age) can explain a substantial degree of the literature-reported biophysical variability observed within a neuron type. Critically, accounting for experimental metadata enables massive cross-study data normalization and reveals that electrophysiological data are far more reproducible across labs than previously appreciated. Using this normalized dataset, we find that neuron types throughout the brain cluster by biophysical properties into 6-9 super-classes. These classes include intuitive clusters, such as fast-spiking basket cells, as well as previously unrecognized clusters, including a novel class of cortical and olfactory bulb interneurons that exhibit persistent activity at theta-band frequencies.

scholarly journals Brain-wide analysis of electrophysiological diversity yields novel categorization of mammalian neuron types

2015 ◽  
Vol 113 (10) ◽  
pp. 3474-3489 ◽  
Author(s):  
Shreejoy J. Tripathy ◽  
Shawn D. Burton ◽  
Matthew Geramita ◽  
Richard C. Gerkin ◽  
Nathaniel N. Urban
Keyword(s):  
Study Data ◽  
Neuronal Diversity ◽  
Biophysical Properties ◽  
Experimental Conditions ◽  
Electrophysiological Properties ◽  
Rich Diversity ◽  
Mammalian Neuron ◽  
Fast Spiking ◽  
The Brain ◽  
Substantial Degree

For decades, neurophysiologists have characterized the biophysical properties of a rich diversity of neuron types. However, identifying common features and computational roles shared across neuron types is made more difficult by inconsistent conventions for collecting and reporting biophysical data. Here, we leverage NeuroElectro, a literature-based database of electrophysiological properties ( www.neuroelectro.org ), to better understand neuronal diversity, both within and across neuron types, and the confounding influences of methodological variability. We show that experimental conditions (e.g., electrode types, recording temperatures, or animal age) can explain a substantial degree of the literature-reported biophysical variability observed within a neuron type. Critically, accounting for experimental metadata enables massive cross-study data normalization and reveals that electrophysiological data are far more reproducible across laboratories than previously appreciated. Using this normalized dataset, we find that neuron types throughout the brain cluster by biophysical properties into six to nine superclasses. These classes include intuitive clusters, such as fast-spiking basket cells, as well as previously unrecognized clusters, including a novel class of cortical and olfactory bulb interneurons that exhibit persistent activity at theta-band frequencies.

scholarly journals Volition and “free will”

2022 ◽  
Author(s):  
Silvia Seghezzi ◽  
Patrick Haggard
Keyword(s):  
Free Will ◽  
Cognitive Neuroscience ◽  
Psychiatric Patients ◽  
Meta Analysis ◽  
Voluntary Action ◽  
Experimental Conditions ◽  
Brain Circuitry ◽  
Definition Of ◽  
The Brain ◽  
Systematic Manipulation

Philosophers have debated the “free will” for centuries, yet it is only in recent years that voluntary actions have become an object of investigation for cognitive neuroscience. This review begins by attempting a definition of volition (i.e., the mental state associated specifically with voluntary actions) that could be relevant for cognitive neuroscience. We then review the neuropsychology of volition. Alterations in voluntary behaviour in neurological and psychiatric patients first suggested the possibility that specific cognitive processes of volition have specific bases in the brain. These findings counter traditional dogmas that human volition is somehow ineffable, and instead suggest that voluntary actions depend on specific brain circuitry that is accessible to scientific investigation.The second part of the review focuses on the experimental psychology of volition. A number of studies have combined a systematic manipulation of experimental conditions, and recording of brain processes associated with voluntary action. We argue that this combination is most likely to identify the brain processes specifically associated with volition, and we therefore review these studies systematically. For example, several studies link the Readiness Potential of the EEG to preparatory conscious preplanning of actions. Further, a meta-analysis of neuroimaging studies (PET/ fMRI) reveals a distinctive pattern of activations for choosing one among many possible actions - a key element of volition. The medial frontal cortex appears to make a key contribution to both these biomarkers of volition.

Morphological Changes in the Brain of Acutely Ill and Weight-Recovered Patients with Anorexia Nervosa

2014 ◽  
Vol 42 (1) ◽  
pp. 7-18 ◽  
Author(s):  
Jochen Seitz ◽  
Katharina Bühren ◽  
Georg G. von Polier ◽  
Nicole Heussen ◽  
Beate Herpertz-Dahlmann ◽  
...  
Keyword(s):  
Anorexia Nervosa ◽  
Cognitive Deficits ◽  
Time Course ◽  
Morphological Changes ◽  
Meta Analysis ◽  
Short Term ◽  
Clinical Prognosis ◽  
Qualitative Review ◽  
Brain Changes ◽  
The Brain

Objective: Acute anorexia nervosa (AN) leads to reduced gray (GM) and white matter (WM) volume in the brain, which however improves again upon restoration of weight. Yet little is known about the extent and clinical correlates of these brain changes, nor do we know much about the time-course and completeness of their recovery. Methods: We conducted a meta-analysis and a qualitative review of all magnetic resonance imaging studies involving volume analyses of the brain in both acute and recovered AN. Results: We identified structural neuroimaging studies with a total of 214 acute AN patients and 177 weight-recovered AN patients. In acute AN, GM was reduced by 5.6% and WM by 3.8% compared to healthy controls (HC). Short-term weight recovery 2–5 months after admission resulted in restitution of about half of the GM aberrations and almost full WM recovery. After 2–8 years of remission GM and WM were nearly normalized, and differences to HC (GM: –1.0%, WM: –0.7%) were no longer significant, although small residual changes could not be ruled out. In the qualitative review some studies found GM volume loss to be associated with cognitive deficits and clinical prognosis. Conclusions: GM and WM were strongly reduced in acute AN. The completeness of brain volume rehabilitation remained equivocal.

Effect of combined citicoline and glutamate antibodies on acute, generalized convusions induced by pentylenetetrazole in mice

2018 ◽  
pp. 24-29
Author(s):  
М.Н. Карпова ◽  
Л.В. Кузнецова ◽  
Н.Ю. Клишина ◽  
Л.А. Ветрилэ
Keyword(s):  
Drug Combination ◽  
Subcutaneous Injection ◽  
Seizure Activity ◽  
Experimental Conditions ◽  
Slow Progression ◽  
Experiment Control ◽  
Effective Doses ◽  
Experimental Justification ◽  
Series Of Experiments ◽  
The Brain

Цель исследования. На 2 моделях острых генерализованных судорог (ОГС), вызванных конвульсантом пентилентетразолом (ПТЗ), изучить эффективность сочетанного применения ноотропа цитиколина - препарата с противосудорожным действием, нейрорегенеративной, нейропротекторной активностью и антител (АТ) к глутамату, обладающих противосудорожной активностью. Методика. Эксперименты выполнены на мышах-самцах линии C57Bl/6 (n = 87) массой 22-28 г. Эффективность сочетанного применения цитиколина и АТ к глутамату изучали на двух моделях ОГС. Выполнено 2 серии экспериментов. В 1-й серии ОГС вызывали внутривенным введением 1% раствора ПТЗ со скоростью 0,01 мл/с. Для изучения эффективности сочетанного применения препаратов определяли минимальное противосудорожное действие цитиколина (Цераксон, «Nicomed Ferrer Internaсional, S.A.») и АТ к глутамату при их внутрибрюшинном введении. С этой целью цитиколин вводили в дозах 500 и 300 мг/кг за 1 ч до введения ПТЗ, АТ к глутамату - в дозах 5 и 2,5 мг/кг за 1 ч 30 мин до введения ПТЗ. АТ к глутамату получали путем гипериммунизации кроликов соответствующим конъюгированным антигеном. Во 2-й серии ОГС вызывали подкожным введением ПТЗ в дозе 85 мг/кг. Для изучения эффективности сочетанного действия изучаемых препаратов последние вводили в минимально действующих дозах, установленных в 1-й серии экспериментов. Контролем во всех сериях опытов служили животные, которым вводили в аналогичных условиях и в том же объеме физиологический раствор. Результаты. Показано, что сочетанное применение цитиколина и АТ к глутамату в минимально действующих дозах (300 и 2,5 мг/кг соответственно) при моделировании ОГС не вызывало повышения судорожной активности мозга и усиления противосудорожных свойств препаратов. Заключение. Cочетанное применение цитиколина и АТ к глутамату в минимально действующих дозах не вызывало повышения судорожной активности мозга, что свидетельствует о безопасности совместного применения препаратов. Проведенное исследование может служить также экспериментальным обоснованием возможности использования сочетанного применения данных препаратов при судорогах с целью замедления прогрессирования нейродегенеративных процессов и благоприятного влияния на когнитивные функции. Aim. To study the effectivity of a combination of citicoline, a nootropic substance with neuroregenerative, neuroprotective, and anticonvulsant actions, and glutamate antibodies (АB) with an anticonvulsant action in two models of acute generalized convulsions (AGC) caused by the convulsant pentylenetetrazole (PTZ). Methods. Experiments were conducted on C57Bl/6 mice (n = 87) weighing 22-28 g. Effects of combined citicoline and glutamate АB were studied on two models of AGС. In the first series of experiments, AGС was induced by intravenous infusion of a 1% PTZ solution at 0.01 ml/sec. In the second series, AGС was induced by a subcutaneous injection of PTZ 85 mg/kg. To evaluate efficacy of the drug combination minimum intraperitoneal anticonvulsant doses of citicoline (Tserakson, Nicomed Ferrer Internacional, S.A.) and glutamate АB were determined. To this purpose, citicoline was administered at 500 and 300 mg/kg 1 h prior to PTZ, and glutamate АB was administered at 5 and 2.5 mg/kg 90 min prior to PTZ. Glutamate АB was obtained by hyperimmunization of rabbits with a respective conjugated antigen. In the second series of experiments, AGС was induced by a subcutaneous injection of PTZ 85 mg/kg. To evaluate the effect of the drug combination, the drugs were administered at the minimum effective doses determined in the first series of experiment. Control animals were injected with the same volume of saline in the same experimental conditions. Results. The combination of citicoline and glutamate AB used at minimum effective doses of 300 and 2.5 mg/kg, respectively, did not increase the seizure activity in the brain and enhanced anticonvulsant properties of the drugs in two models of AGС. Conclusion. The combination of citicoline and glutamate AT at minimum effective doses did not increase the convulsive activity in the brain, which supported safety of the drug combination. Besides, this study can serve as an experimental justification for using the drug combination in convulsions to favorably influence cognitive functions and slow progression of neurodegenerative processes.

The Auditory Brainstem Implant

2019 ◽  
pp. 758-770
Author(s):  
Robert V. Shannon
Keyword(s):  
Surgical Technique ◽  
Cochlear Nucleus ◽  
Meta Analysis ◽  
Auditory Brainstem ◽  
Auditory Information ◽  
Speech Understanding ◽  
Auditory Neurons ◽  
Auditory Brainstem Implant ◽  
The Brain ◽  
Implanted Device

The auditory brainstem implant (ABI) is a surgically implanted device to electrically stimulate auditory neurons in the cochlear nucleus complex of the brainstem in humans to restore hearing sensations. The ABI is similar in function to a cochlear implant, but overall outcomes are poorer. However, recent applications of the ABI to new patient populations and improvements in surgical technique have led to significant improvements in outcomes. While the ABI provides hearing benefits to patients, the outcomes challenge our understanding of how the brain processes neural patterns of auditory information. The neural pattern of activation produced by an ABI is highly unnatural, yet some patients achieve high levels of speech understanding. Based on a meta-analysis of ABI surgeries and outcomes, a theory is proposed of a specialized sub-system of the cochlear nucleus that is critical for speech understanding.

The Effect of Water-Based Therapy Compared to Land-Based Therapy on Balance and Gait Parameters of Patients with Stroke: A Systematic Review

2021 ◽  
pp. 1-9
Author(s):  
Nour Zughbor ◽  
Aisha Alwahshi ◽  
Rahaf Abdelrahman ◽  
Zeina Elnekiti ◽  
Hoda Elkareish ◽  
...  
Keyword(s):  
Meta Analysis ◽  
Berg Balance Scale ◽  
Primary Outcome Measure ◽  
Balance System ◽  
Effect Of Water ◽  
Gait Parameters ◽  
Water Based ◽  
Biodex Balance System ◽  
Therapy Studies ◽  
The Brain

<b><i>Introduction:</i></b> Stroke is defined as the lack of blood supply to the brain, leading to rapid loss of brain function presenting with impairments such as muscle weakness, spasticity, lack of coordination, and proprioception loss. Both hydrotherapy and land-based therapy aim to target these aspects in the process of rehabilitation. The study aims to determine the effectiveness of water-based therapy on balance and gait of patients with stroke compared to land-based therapy. <b><i>Methods:</i></b> Data for this review were extracted from databases such as CINAHL, OTseeker, Ovid, PEDro, and PubMed (MEDLINE) and other sources such as Google Scholar. PRISMA guidelines were followed to exclude irrelevant studies. Only randomized controlled trials (RCTs) were included, and methodological quality was assessed using the PEDro scale. A meta-analysis of extracted data was conducted. <b><i>Results:</i></b> A total of 16 relevant RCTs were included for the review (<i>n</i> = 412 participants). All RCTs investigated the effect of water-based therapy compared to land-based therapy on balance and gait of patients with stroke. Meta-analysis of studies that used the Berg Balance Scale (BBS) as a primary outcome measure favored land-based therapy. Studies that used the Good Balance System (GBS) and the Biodex Balance System (BioBS) to measure the changes in anteroposterior sway and mediolateral sway favored water-based therapy. The overall pooled effect favored land-based therapy in improving gait parameters. <b><i>Conclusion:</i></b> Findings from meta-analysis support the effectiveness of land-based therapy in the improvement of balance and gait parameters of patients with stroke. However, the evidence for water-based therapy continues to be limited, and higher quality studies are required to determine the effectiveness of water-based therapy on patients with stroke, particularly on balance and gait.

scholarly journals The L1-dependant and Pol III transcribed Alu retrotransposon, from its discovery to innate immunity

2021 ◽  
Vol 48 (3) ◽  
pp. 2775-2789
Author(s):  
Ludwig Stenz
Keyword(s):  
Human Genome ◽  
Viral Infections ◽  
De Novo ◽  
Current Knowledge ◽  
Innate Immune ◽  
De Novo Mutation ◽  
Neuronal Diversity ◽  
Alu Sequences ◽  
Pol Iii ◽  
The Brain

AbstractThe 300 bp dimeric repeats digestible by AluI were discovered in 1979. Since then, Alu were involved in the most fundamental epigenetic mechanisms, namely reprogramming, pluripotency, imprinting and mosaicism. These Alu encode a family of retrotransposons transcribed by the RNA Pol III machinery, notably when the cytosines that constitute their sequences are de-methylated. Then, Alu hijack the functions of ORF2 encoded by another transposons named L1 during reverse transcription and integration into new sites. That mechanism functions as a complex genetic parasite able to copy-paste Alu sequences. Doing that, Alu have modified even the size of the human genome, as well as of other primate genomes, during 65 million years of co-evolution. Actually, one germline retro-transposition still occurs each 20 births. Thus, Alu continue to modify our human genome nowadays and were implicated in de novo mutation causing diseases including deletions, duplications and rearrangements. Most recently, retrotransposons were found to trigger neuronal diversity by inducing mosaicism in the brain. Finally, boosted during viral infections, Alu clearly interact with the innate immune system. The purpose of that review is to give a condensed overview of all these major findings that concern the fascinating physiology of Alu from their discovery up to the current knowledge.

Ethnic Differences in the Smoking-Related Risk of Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis

2021 ◽  
Author(s):  
Daniele Piovani ◽  
Claudia Pansieri ◽  
Soumya R R Kotha ◽  
Amanda C Piazza ◽  
Celia-Louise Comberg ◽  
...  
Keyword(s):  
Inflammatory Bowel Disease ◽  
Latin American ◽  
Bowel Disease ◽  
Meta Analysis ◽  
Study Data ◽  
Future Research ◽  
Related Risk ◽  
Increased Risk ◽  
Inflammatory Bowel

Abstract Background and aims The association between smoking and inflammatory bowel disease (IBD) relies on old meta-analyses including exclusively non-Jewish White populations. Uncertainty persists regarding the role of smoking in other ethnicities. Methods We systematically searched Medline/PubMed, Embase and Scopus for studies examining tobacco smoking and the risk of developing IBD, i.e., Crohn’s disease (CD) or ulcerative colitis (UC). Two authors independently extracted study data and assessed each study’s risk-of-bias. We examined heterogeneity and small-study effect, and calculated summary estimates using random-effects models. Stratified analyses and meta-regression were employed to study the association between study-level characteristics and effect estimates. The strength of epidemiological evidence was assessed through prespecified criteria. Results We synthesized 57 studies examining the smoking-related risk of developing CD and UC. Non-Jewish White smokers were at increased risk of CD (29 studies; RR: 1.95, 95% CI: 1.69‒2.24; moderate evidence). No association was observed in Asian, Jewish and Latin-American populations (11 studies; RR: 0.97; 95% CI: 0.83–1.13), with no evidence of heterogeneity across these ethnicities. Smokers were at reduced risk of UC (51 studies; RR: 0.55, 95% CI: 0.48–0.64; weak evidence) irrespectively of ethnicity; however, cohort studies, large studies and those recently published showed attenuated associations. Conclusions This meta-analysis did not identify any increased risk of CD in smokers in ethnicities other than non-Jewish Whites, and confirmed the protective effect of smoking on UC occurrence. Future research should characterize the genetic background of CD patients across different ethnicities to improve our understanding on the role of smoking in CD pathogenesis.

Regional blood flow in the brain and spinal cord of hypothermic rats

1989 ◽  
Vol 257 (3) ◽  
pp. H785-H790
Author(s):  
T. Sakamoto ◽  
W. W. Monafo
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
Brain Stem ◽  
Regional Blood Flow ◽  
Experimental Conditions ◽  
Pentobarbital Sodium ◽  
Arterial Blood ◽  
Group A ◽  
Group B ◽  
The Brain

[14C]butanol tissue uptake was used to measure simultaneously regional blood flow in three regions of the brain (cerebral and cerebellar hemispheres and brain stem) and in five levels of the spinal cord in 10 normothermic rats (group A) and in 10 rats in which rectal temperature had been lowered to 27.7 +/- 0.3 degrees C by applying ice to the torso (group B). Pentobarbital sodium anesthesia was used. Mean arterial blood pressure varied minimally between groups as did arterial pH, PO2, and PCO2. In group A, regional spinal cord blood flow (rSCBF) varied from 49.7 +/- 1.6 to 62.6 +/- 2.1 ml.min-1.100 g-1; in brain, regional blood flow (rBBF) averaged 74.4 +/- 2.3 ml.min-1.100 g-1 in the whole brain and was highest in the brain stem. rSCBF in group B was elevated in all levels of the cord by 21-34% (P less than 0.05). rBBF, however, was lowered by 21% in the cerebral hemispheres (P less than 0.001) and by 14% in the brain as a whole (P less than 0.05). The changes in calculated vascular resistance tended to be inversely related to blood flow in all tissues. We conclude that rBBF is depressed in acutely hypothermic pentobarbital sodium-anesthetized rats, as has been noted before, but that rSCBF rises under these experimental conditions. The elevation of rSCBF in hypothermic rats confirms our previous observations.

Abstract 16170: Impact of Anemia on Outcomes in Patients With Heart Failure With Preserved Ejection Fraction: A Meta-analysis

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Monil Majmundar ◽  
Ashish Kumar ◽  
Rajkumar P Doshi ◽  
Palak shah ◽  
Mariam Shariff ◽  
...  
Keyword(s):  
Heart Failure ◽  
Ejection Fraction ◽  
Publication Bias ◽  
Meta Analysis ◽  
Final Analysis ◽  
Study Data ◽  
Curve Analysis ◽  
Secondary Outcome ◽  
Preserved Ejection Fraction ◽  
All Cause Mortality

Introduction: The effect of anemia on outcomes in Heart failure with preserved ejection fraction (HFpEF) patients is not well-established. Some previous studies have shown increased mortality and hospitalizations in HFpEF patients with anemia. Hypothesis: We hypothesize that anemia affects all-cause mortality and hospitalization in HFpEF patients. Methods: A review of literature for studies comparing outcomes in HFpEF with and without anemia was done in PubMed, MEDLINE, and EMBASE databases through June 1st, 2020. The standard definitions of HFpEF and anemia were used for inclusion criteria. Two investigators extracted the study data independently. The primary outcome of interest was all-cause mortality. The secondary outcome was all-cause hospitalizations. We used the PM estimator of Tau with Knapp-Hartung adjustment to pool adjusted hazard ratio (HR) and 95% confidence interval (CI). P curve analysis was used to assess publication bias. R version 3.6.2 was used for all statistical analyses. Results: Seven studies (23,424 patients) were included in the final analysis. Anemia in patients with HFpEF was associated with higher rates of all-cause mortality [HR: 1.35, 95% CI: 1.17-1.55]. Additionally, anemia in HFpEF patients was associated with higher rates of all-cause hospitalization [HR: 1.22, 95% CI: 1.03-1.44]. P curve analysis for all-cause mortality didn’t report publication bias or P hacking (Figure) . Conclusions: Anemia in HFpEF patients was associated with higher rates of all-cause mortality and all-cause hospitalizations compared to HFpEF patients without anemia.

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