Search results for "cortical"
showing 10 items of 324 documents
GABA—from Inhibition to Cognition:Emerging Concepts
2018
Neural functioning and plasticity can be studied on different levels of organization and complexity ranging from the molecular and synaptic level to neural circuitry of whole brain networks. Across neuroscience different methods are being applied to better understand the role of various neurotransmitter systems in the evolution of perception and cognition. GABA is the main inhibitory neurotransmitter in the adult mammalian brain and, depending on the brain region, up to 25% of the total number of cortical neurons are GABAergic interneurons. At the one end of the spectrum, GABAergic neurons have been accurately described with regard to cell morphological, molecular, and electrophysiological…
Cortical network mechanisms of response inhibition
2020
SummaryBoth the right inferior frontal gyrus (rIFG) and the pre-supplementary motor area (pre-SMA) are crucial for successful response inhibition. However, the particular functional roles of those two regions have been controversially debated for more than a decade now. It is unclear whether the rIFG directly initiates stopping or serves an attentional function, whereas the stopping is triggered by the pre-SMA. The current multimodal MEG/fMRI study sought to clarify the role and temporal activation order of both regions in response inhibition using a selective stopping task. This task dissociates inhibitory from attentional processes. Our results reliably reveal a temporal precedence of rIF…
Action in Perception: Prominent Visuo-Motor Functional Symmetry in Musicians during Music Listening.
2015
Musical training leads to sensory and motor neuroplastic changes in the human brain. Motivated by findings on enlarged corpus callosum in musicians and asymmetric somatomotor representation in string players, we investigated the relationship between musical training, callosal anatomy, and interhemispheric functional symmetry during music listening. Functional symmetry was increased in musicians compared to nonmusicians, and in keyboardists compared to string players. This increased functional symmetry was prominent in visual and motor brain networks. Callosal size did not significantly differ between groups except for the posterior callosum in musicians compared to nonmusicians. We conclude…
An extensive pattern of atypical neural speech-sound discrimination in newborns at risk of dyslexia.
2019
Objective: Identifying early signs of developmental dyslexia, associated with deficient speech-sound processing, is paramount to establish early interventions. We aimed to find early speech-sound processing deficiencies in dyslexia, expecting diminished and atypically lateralized event-related potentials (ERP) and mismatch responses (MMR) in newborns at dyslexia risk. Methods: ERPs were recorded to a pseudoword and its variants (vowel-duration, vowel-identity, and syllable-frequency changes) from 88 newborns at high or no familial risk. The response significance was tested, and group, laterality, and frontality effects were assessed with repeated-measures ANOVA. Results: An early positive a…
Hallazgos histológicos y ultraestructurales en áreas de displasia cortical focal de pacientes pediátricos intervenidos por epilepsia refractaria
2022
Las malformaciones del desarrollo cortical (MDC) comprenden un amplio grupo de enfermedades malformativas del desarrollo de la corteza cerebral, que pueden conducir a crisis epilépticas, habitualmente refractarias a tratamiento médico, en la infancia o la juventud. La displasia cortical focal (DCF) es reconocida como una de las MDC más epileptogénica y se clasifica en tres subtipos dependiendo del tipo de diseminación cortical (radial o tangencial) y la presencia o ausencia de alteraciones citológicas (neuronas dismórficas y/o células en balón). Muchas proteínas relacionadas con la migración neuronal y neurogénesis, como la Doblecortina (DCX) se han estudiado en este tipo de patologías. La …
Rapid developmental switch in the mechanisms driving early cortical columnar networks
2006
The immature cerebral cortex self-organizes into local neuronal clusters long before it is activated by patterned sensory inputs. In the cortical anlage of newborn mammals, neurons coassemble through electrical or chemical synapses either spontaneously or by activation of transmitter-gated receptors. The neuronal network and the cellular mechanisms underlying this cortical self-organization process during early development are not completely understood. Here we show in an intact in vitro preparation of the immature mouse cerebral cortex that neurons are functionally coupled in local clusters by means of propagating network oscillations in the beta frequency range. In the newborn mouse, this…
Hypermineralocorticoidism and hypertension
1971
Die mit Hypokaliamie, Uberproduktion von Mineralocorticoiden (Aldosteron und/oder Corticosteron und Desoxycorticosteron) und Aktivitatsanderungen des Renin-Angiotensinsystems einhergehenden Hochdrucksformen werden beschrieben. Sie lassen sich nach willkurlich gewahlten biochemischen Kriterien in drei Gruppen einteilen: a) Hypermineralocorticoidismus mit Reninsuppression und Aldosteronismus, b) Hypermineralocorticoidismus mit Reninund Aldosteronsuppression und c) Hypermineralocorticoidismus mit erhohtem Plasmarenin und Aldosteronismus. Jede dieser Gruppen besteht aus mehreren Syndromen, die sich durch ihr adrenocorticales Sekretionsmuster und/oder ihre morphologischen Nebennierenrindenverand…
Multiple endocrine neoplasia type 1 gene expression is normal in sporadic adrenocortical tumors.
2000
Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant disorder with neoplasia of the anterior pituitary, the parathyroid, the endocrine pancreas and other endocrine tissues including the adrenal cortex. The tumor-suppressor gene causing this disease was identified at the gene locus 11q13. We recently reported that adrenocortical carcinomas frequently show loss of heterozygosity (LOH) of 11q13, but do not contain point mutations within the MEN1-coding region. To investigate whether reduced gene expression (for example by mutations within the MEN1 promoter) may contribute to the tumorigenesis of sporadic adrenocortical tumors, 24 adrenocortical specimen were studied by Northern …
Exercise loading and cortical bone distribution at the tibial shaft
2011
Cortical bone is not a uniform tissue, and its apparent density [cortical volumetric density (vBMD)] varies around the bone cross-section as well as along the axial length of the bone. It is not yet known, whether the varying vBMD distribution is attributable to modulation in the predominant loads affecting bone. The aim of the present study was to compare the cortical bone mass distribution through the bone cortex (radial distribution) and around the center of mass (polar distribution) among 221 premenopausal women aged 17-40 years representing athletes involved in high impact, odd impact, high magnitude, repetitive low impact, repetitive non-impact sports and leisure time physical activit…
Long-term leisure time physical activity and properties of bone: A twin study
2009
Effects of physical activity on bone properties, when controlled for genetic effects, are not fully understood. We aimed to study the association between long-term leisure time physical activity (LTPA) and bone properties using twin pairs known to be discordant for leisure time physical activity for at least 30 yr. Volumetric BMD and geometric properties were measured at the tibia shaft and distal end using pQCT in 16 middle-aged (50-74 yr) same-sex twin pairs (seven monozygotic [MZ] and nine dizygotic [DZ] pairs) selected from a population-based cohort. Paired differences between active and inactive co-twins were studied. Active members of MZ twin pairs had larger cortical bone cross-secti…