Functional topography of auditory areas derived from the combination of electrophysiological recordings and cortical electrical stimulation.

Mapping Intimacies ◽

10.31219/osf.io/fxdg5 ◽

2021 ◽

Author(s):

Agnès Trébuchon ◽

F.-Xavier Alario ◽

Catherine Liégeois-Chauvel

Keyword(s):

Language Processing ◽

Hemispheric Specialization ◽

Functional Characterization ◽

Posterior Part ◽

Epileptic Seizures ◽

Superior Temporal Gyrus ◽

Time Frequency ◽

Depth Electrodes ◽

Electrophysiological Recordings

The posterior part of the superior temporal gyrus (STG) has long been known to be a crucial hub for auditory and language processing, at the crossroad of the functionally defined ventral and dorsal pathways. Anatomical studies have shown that this “auditory cortex” is composed of several cytoarchitectonic areas whose limits do not consistently match macro-anatomic landmarks like gyral and sulcal borders. The functional characterization of these areas derived from brain imaging studies has some limitations, even when high field functional magnetic resonance imaging (fMRI) is used, because of the variability observed in the extension of these areas between hemispheres and individuals. In patients implanted with depth electrodes, in vivo recordings and direct electrical stimulations of the different sub-parts of the posterior STG allow to delineate different auditory sub-fields in Heschl’s gyrus (HG), Planum Temporale (PT), the posterior part of the superior temporal gyrus anterior to HG, the posterior superior temporal sulcus (STS), and the region at the parietal-temporal boundary commonly labelled “Spt”. We describe how this delineation can be achieved using data from electrical cortical stimulation combined with local field potentials and time frequency analysis recorded as responses to pure tones and syllables. We show the differences in functional roles between the primary and non-primary auditory areas, in the left and the right hemispheres. We discuss how these findings help understanding the auditory semiology of certain epileptic seizures and, more generally, the neural substrate of hemispheric specialization for language.

Download Full-text

Functional Topography of Auditory Areas Derived From the Combination of Electrophysiological Recordings and Cortical Electrical Stimulation

Frontiers in Human Neuroscience ◽

10.3389/fnhum.2021.702773 ◽

2021 ◽

Vol 15 ◽

Author(s):

Agnès Trébuchon ◽

F.-Xavier Alario ◽

Catherine Liégeois-Chauvel

Keyword(s):

Auditory Cortex ◽

Language Processing ◽

Hemispheric Specialization ◽

Posterior Part ◽

Primary Auditory Cortex ◽

Epileptic Seizures ◽

Superior Temporal Gyrus ◽

Depth Electrodes ◽

Electrophysiological Recordings ◽

The Right

The posterior part of the superior temporal gyrus (STG) has long been known to be a crucial hub for auditory and language processing, at the crossroad of the functionally defined ventral and dorsal pathways. Anatomical studies have shown that this “auditory cortex” is composed of several cytoarchitectonic areas whose limits do not consistently match macro-anatomic landmarks like gyral and sulcal borders. The only method to record and accurately distinguish neuronal activity from the different auditory sub-fields of primary auditory cortex, located in the tip of Heschl and deeply buried in the Sylvian fissure, is to use stereotaxically implanted depth electrodes (Stereo-EEG) for pre-surgical evaluation of patients with epilepsy. In this prospective, we focused on how anatomo-functional delineation in Heschl’s gyrus (HG), Planum Temporale (PT), the posterior part of the STG anterior to HG, the posterior superior temporal sulcus (STS), and the region at the parietal-temporal boundary commonly labeled “SPT” can be achieved using data from electrical cortical stimulation combined with electrophysiological recordings during listening to pure tones and syllables. We show the differences in functional roles between the primary and non-primary auditory areas, in the left and the right hemispheres. We discuss how these findings help understanding the auditory semiology of certain epileptic seizures and, more generally, the neural substrate of hemispheric specialization for language.

Download Full-text

The Neurobiology of Sensory and Language Processing in Language-Impaired Children

Journal of Cognitive Neuroscience ◽

10.1162/jocn.1993.5.2.235 ◽

1993 ◽

Vol 5 (2) ◽

pp. 235-253 ◽

Cited By ~ 215

Author(s):

Helen J. Neville ◽

Sharon A. Coffey ◽

Phillip J. Holcomb ◽

Paula Tallal

Keyword(s):

Language Processing ◽

Sentence Processing ◽

Language Impairment ◽

Cognitive Abilities ◽

Temporal Discrimination ◽

Hemispheric Specialization ◽

Superior Temporal Gyrus ◽

Language Impaired ◽

Neurophysiological Studies ◽

Abnormal Performance

Clinical, behavioral, and neurophysiological studies of developmental language impairment (LI), including reading disability (RD), have variously emphasized different factors that may contribute to this disorder. These include abnormal sensory processing within both the auditory and visual modalities and deficits in linguistic skills and in general cognitive abilities. In this study we employed the event-related brain potential (ERP) technique in a series of studies to probe and compare Merent aspects of functioning within the same sample of LI/RD children. Within the group multiple aspects of processing were affected, but heterogeneously across the sample. ERP components linked to processing within the superior temporal gyrus were abnormal in a subset of children that displayed abnormal performance on an auditory temporal discrimination task. An early component of the visual ERP was reduced in amplitude in the group as a whole. The relevance of this effect to current conceptions of substreams within the visual system is discussed. During a sentence processing task abnormal hemispheric specialization was observed in a subset of children who scored poorly on tests of grammar. By contrast the group as a whole displayed abnormally large responses to words requiring contextual integration. The results imply that multiple factors can contribute to the profile of language impairment and that different and specific deficits occur heterogeneously across populations of LI/RD children.

Download Full-text

Functional characterization of human brown adipose tissue metabolism

Biochemical Journal ◽

10.1042/bcj20190464 ◽

2020 ◽

Vol 477 (7) ◽

pp. 1261-1286 ◽

Cited By ~ 3

Author(s):

Marie Anne Richard ◽

Hannah Pallubinsky ◽

Denis P. Blondin

Keyword(s):

Adipose Tissue ◽

Brown Adipose Tissue ◽

Functional Characterization ◽

Human Infants ◽

Positron Emission ◽

Brown Adipose ◽

Treatment Of Obesity ◽

And Function

Brown adipose tissue (BAT) has long been described according to its histological features as a multilocular, lipid-containing tissue, light brown in color, that is also responsive to the cold and found especially in hibernating mammals and human infants. Its presence in both hibernators and human infants, combined with its function as a heat-generating organ, raised many questions about its role in humans. Early characterizations of the tissue in humans focused on its progressive atrophy with age and its apparent importance for cold-exposed workers. However, the use of positron emission tomography (PET) with the glucose tracer [18F]fluorodeoxyglucose ([18F]FDG) made it possible to begin characterizing the possible function of BAT in adult humans, and whether it could play a role in the prevention or treatment of obesity and type 2 diabetes (T2D). This review focuses on the in vivo functional characterization of human BAT, the methodological approaches applied to examine these features and addresses critical gaps that remain in moving the field forward. Specifically, we describe the anatomical and biomolecular features of human BAT, the modalities and applications of non-invasive tools such as PET and magnetic resonance imaging coupled with spectroscopy (MRI/MRS) to study BAT morphology and function in vivo, and finally describe the functional characteristics of human BAT that have only been possible through the development and application of such tools.

Download Full-text

Automated System for Epileptic Seizures Prediction based on Multi-Channel Recordings of Electrical Brain Activity

Information and Control Systems ◽

10.31799/1684-8853-2018-4-115-122 ◽

2018 ◽

pp. 115-122 ◽

Cited By ~ 1

Author(s):

V. A. Maksimenko ◽

A. A. Harchenko ◽

A. Lüttjohann

Keyword(s):

Epileptic Seizure ◽

Brain Activity ◽

Epileptic Seizures ◽

Automated System ◽

Brain Computer Interfaces ◽

Electrical Brain Activity ◽

Computer Interfaces ◽

Prediction And Prevention ◽

The Brain

Introduction: Now the great interest in studying the brain activity based on detection of oscillatory patterns on the recorded data of electrical neuronal activity (electroencephalograms) is associated with the possibility of developing brain-computer interfaces. Braincomputer interfaces are based on the real-time detection of characteristic patterns on electroencephalograms and their transformation into commands for controlling external devices. One of the important areas of the brain-computer interfaces application is the control of the pathological activity of the brain. This is in demand for epilepsy patients, who do not respond to drug treatment.Purpose: A technique for detecting the characteristic patterns of neural activity preceding the occurrence of epileptic seizures.Results:Using multi-channel electroencephalograms, we consider the dynamics of thalamo-cortical brain network, preceded the occurrence of an epileptic seizure. We have developed technique which allows to predict the occurrence of an epileptic seizure. The technique has been implemented in a brain-computer interface, which has been tested in-vivo on the animal model of absence epilepsy.Practical relevance:The results of our study demonstrate the possibility of epileptic seizures prediction based on multichannel electroencephalograms. The obtained results can be used in the development of neurointerfaces for the prediction and prevention of seizures of various types of epilepsy in humans.

Download Full-text

Functional characterization of a full length pregnane X receptor, expression in vivo, and identification of PXR alleles, in Zebrafish (Danio rerio)

Aquatic Toxicology ◽

10.1016/j.aquatox.2013.09.014 ◽

2013 ◽

Vol 142-143 ◽

pp. 447-457 ◽

Cited By ~ 30

Author(s):

Afonso C.D. Bainy ◽

Akira Kubota ◽

Jared V. Goldstone ◽

Roger Lille-Langøy ◽

Sibel I. Karchner ◽

...

Keyword(s):

Danio Rerio ◽

Functional Characterization ◽

Pregnane X Receptor ◽

Full Length ◽

Receptor Expression

Download Full-text

Functional identification of ygiP as a positive regulator of the ttdA-ttdB-ygjE operon

Microbiology ◽

10.1099/mic.0.28753-0 ◽

2006 ◽

Vol 152 (7) ◽

pp. 2129-2135 ◽

Cited By ~ 17

Author(s):

Taku Oshima ◽

Francis Biville

Keyword(s):

Functional Characterization ◽

Anaerobic Growth ◽

Functional Identification ◽

New Members ◽

E Coli ◽

Inner Membrane Protein ◽

Tartrate Dehydratase

Functional characterization of unknown genes is currently a major task in biology. The search for gene function involves a combination of various in silico, in vitro and in vivo approaches. Available knowledge from the study of more than 21 LysR-type regulators in Escherichia coli has facilitated the classification of new members of the family. From sequence similarities and its location on the E. coli chromosome, it is suggested that ygiP encodes a lysR regulator controlling the expression of a neighbouring operon; this operon encodes the two subunits of tartrate dehydratase (TtdA, TtdB) and YgiE, an integral inner-membrane protein possibly involved in tartrate uptake. Expression of tartrate dehydratase, which converts tartrate to oxaloacetate, is required for anaerobic growth on glycerol as carbon source in the presence of tartrate. Here, it has been demonstrated that disruption of ygiP, ttdA or ygjE abolishes tartrate-dependent anaerobic growth on glycerol. It has also been shown that tartrate-dependent induction of the ttdA-ttdB-ygjE operon requires a functional YgiP.

Download Full-text

Functional Characterization of the mazEF Toxin-Antitoxin System in the Pathogenic Bacterium Agrobacterium tumefaciens

Microorganisms ◽

10.3390/microorganisms9051107 ◽

2021 ◽

Vol 9 (5) ◽

pp. 1107

Author(s):

Wonho Choi ◽

Yoshihiro Yamaguchi ◽

Ji-Young Park ◽

Sang-Hyun Park ◽

Hyeok-Won Lee ◽

...

Keyword(s):

Agrobacterium Tumefaciens ◽

Physiological Function ◽

Functional Characterization ◽

Site Directed Mutagenesis ◽

In Vitro Assays ◽

Cell Growth Inhibition ◽

The Right

Agrobacterium tumefaciens is a pathogen of various plants which transfers its own DNA (T-DNA) to the host plants. It is used for producing genetically modified plants with this ability. To control T-DNA transfer to the right place, toxin-antitoxin (TA) systems of A. tumefaciens were used to control the target site of transfer without any unintentional targeting. Here, we describe a toxin-antitoxin system, Atu0939 (mazE-at) and Atu0940 (mazF-at), in the chromosome of Agrobacterium tumefaciens. The toxin in the TA system has 33.3% identity and 45.5% similarity with MazF in Escherichia coli. The expression of MazF-at caused cell growth inhibition, while cells with MazF-at co-expressed with MazE-at grew normally. In vivo and in vitro assays revealed that MazF-at inhibited protein synthesis by decreasing the cellular mRNA stability. Moreover, the catalytic residue of MazF-at was determined to be the 24th glutamic acid using site-directed mutagenesis. From the results, we concluded that MazF-at is a type II toxin-antitoxin system and a ribosome-independent endoribonuclease. Here, we characterized a TA system in A. tumefaciens whose understanding might help to find its physiological function and to develop further applications.

Download Full-text

Multimodal in vivo recording using transparent graphene microelectrodes illuminates spatiotemporal seizure dynamics at the microscale

Communications Biology ◽

10.1038/s42003-021-01670-9 ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Nicolette Driscoll ◽

Richard E. Rosch ◽

Brendan B. Murphy ◽

Arian Ashourvan ◽

Ramya Vishnubhotla ◽

...

Keyword(s):

Temporal Resolution ◽

Spatial Scales ◽

Epileptic Seizures ◽

Therapeutic Interventions ◽

State Transitions ◽

Integrated Analysis ◽

High Temporal Resolution ◽

Seizure Onset ◽

Acute Seizures

AbstractNeurological disorders such as epilepsy arise from disrupted brain networks. Our capacity to treat these disorders is limited by our inability to map these networks at sufficient temporal and spatial scales to target interventions. Current best techniques either sample broad areas at low temporal resolution (e.g. calcium imaging) or record from discrete regions at high temporal resolution (e.g. electrophysiology). This limitation hampers our ability to understand and intervene in aberrations of network dynamics. Here we present a technique to map the onset and spatiotemporal spread of acute epileptic seizures in vivo by simultaneously recording high bandwidth microelectrocorticography and calcium fluorescence using transparent graphene microelectrode arrays. We integrate dynamic data features from both modalities using non-negative matrix factorization to identify sequential spatiotemporal patterns of seizure onset and evolution, revealing how the temporal progression of ictal electrophysiology is linked to the spatial evolution of the recruited seizure core. This integrated analysis of multimodal data reveals otherwise hidden state transitions in the spatial and temporal progression of acute seizures. The techniques demonstrated here may enable future targeted therapeutic interventions and novel spatially embedded models of local circuit dynamics during seizure onset and evolution.

Download Full-text

Cdc13 N-Terminal Dimerization, DNA Binding, and Telomere Length Regulation

Molecular and Cellular Biology ◽

10.1128/mcb.00515-10 ◽

2010 ◽

Vol 30 (22) ◽

pp. 5325-5334 ◽

Cited By ~ 23

Author(s):

Meghan T. Mitchell ◽

Jasmine S. Smith ◽

Mark Mason ◽

Sandy Harper ◽

David W. Speicher ◽

...

Keyword(s):

Dna Binding ◽

Telomere Length ◽

Functional Characterization ◽

Point Mutations ◽

Telomeric Dna ◽

Dna Binding Domains ◽

Binding Domains ◽

Length Regulation ◽

Telomere Length Regulation

ABSTRACT The essential yeast protein Cdc13 facilitates chromosome end replication by recruiting telomerase to telomeres, and together with its interacting partners Stn1 and Ten1, it protects chromosome ends from nucleolytic attack, thus contributing to genome integrity. Although Cdc13 has been studied extensively, the precise role of its N-terminal domain (Cdc13N) in telomere length regulation remains unclear. Here we present a structural, biochemical, and functional characterization of Cdc13N. The structure reveals that this domain comprises an oligonucleotide/oligosaccharide binding (OB) fold and is involved in Cdc13 dimerization. Biochemical data show that Cdc13N weakly binds long, single-stranded, telomeric DNA in a fashion that is directly dependent on domain oligomerization. When introduced into full-length Cdc13 in vivo, point mutations that prevented Cdc13N dimerization or DNA binding caused telomere shortening or lengthening, respectively. The multiple DNA binding domains and dimeric nature of Cdc13 offer unique insights into how it coordinates the recruitment and regulation of telomerase access to the telomeres.

Download Full-text