Search results for "General Neuroscience"
showing 10 items of 2366 documents
Oscillatory Dynamics Underlying Perceptual Narrowing of Native Phoneme Mapping from 6 to 12 Months of Age
2016
During the first months of life, human infants process phonemic elements from all languages similarly. However, by 12 months of age, as language-specific phonemic maps are established, infants respond preferentially to their native language. This process, known as perceptual narrowing, supports neural representation and thus efficient processing of the distinctive phonemes within the sound environment. Although oscillatory mechanisms underlying processing of native and non-native phonemic contrasts were recently delineated in 6-month-old infants, the maturational trajectory of these mechanisms remained unclear. A group of typically developing infants born into monolingual English families, …
Transient oligemia is associated with long-term changes in binding densities of cortical inhibitory GABAA receptors in the rat brain
2009
Recently, we could demonstrate in rats that a short transient oligemic period of only 20-minute duration, induced by systemic hypotension, resulted in a transient decline of spatial memory capacities without any histological damage over a subsequent period of 6 months. In our present study, we checked for more subtle alterations within the highly vulnerable hippocampal CA1 subfield using quantification of neuronal cell density and semi-quantitative analysis of the ischemia-sensitive protein MAP2. Since hippocampal excitatory and inhibitory neurotransmitter receptors are crucially involved in spatial memory processes, quantitative in vitro receptor autoradiography was performed using [(3)H]M…
The effects of nitric oxide on striatal serotoninergic transmission involve multiple targets: an in vivo microdialysis study in the awake rat
2004
Abstract The role of endogenous nitric oxide (NO) in N -methyl- d -aspartate (NMDA)-induced modulation of serotonin (5-HT) release in the striatum of freely moving rats has been studied using microdialysis technique. NMDA-induced increase in 5-HT release was significantly inhibited by selective nitric oxide synthase (nNOS) inhibitor S -methylthiocitrulline (S-Me-TC), ONOO − scavenger l -cysteine ( l -cys), and guanylate cyclase (GC) inhibitor 1 H [1,2,4]oxadiazolo[4,3- a ]quinoxalin-1-one (ODQ). These data suggest that modulation of 5-HT levels is linked to the formation of NO produced by NMDA receptor activation and that endogenously produced NO increases 5-HT concentrations both by stimul…
Long-range intralaminar noise correlations in the barrel cortex
2015
Identifying the properties of correlations in the firing of neocortical neurons is central to our understanding of cortical information processing. It has been generally assumed, by virtue of the columnar organization of the neocortex, that the firing of neurons residing in a certain vertical domain is highly correlated. On the other hand, firing correlations between neurons steeply decline with horizontal distance. Technical difficulties in sampling neurons with sufficient spatial information have precluded the critical evaluation of these notions. We used 128-channel “silicon probes” to examine the spike-count noise correlations during spontaneous activity between multiple neurons with i…
Electrophysiological correlates of the cognitive control processes underpinning mixing and switching costs
2016
Typically, in task-switching contexts individuals are slower and less accurate when repeating a task in mixed blocks compared to single-task blocks (mixing cost) and when switching to a new task compared to repeating a previous one (switch cost). Previous research has shown that distinct electrophysiological correlates underlie these two phenomena. However, this evidence is not a consistent result. The goal of this study was to better characterize differences between the control processes involved in mixing and switch costs. To this aim, we examined event-related potentials (ERPs) evoked during a cued task-switching experiment. In order to minimize the confounding effects of cognitive deman…
Distribution of basal-expressed c-fos-like immunoreactive cells of the periaqueductal grey matter of the rat.
1996
The distribution of c-fos proto-oncogene expression has been studied in the periaqueductal grey matter (PAG) of non-intentional-stimulated rats by immunohistochemistry. A mean number of 53 +/- 9 Fos-like immunoreactive cells per hemiPAG, distributed into three groups, dorsolateral, lateral and ventrolateral, was found. The dorsolateral and the lateral groups appeared along the entire rostrocaudal PAG, whereas the ventrolateral group appeared only in the caudal half. These results reveal new data on the number and extent of the longitudinal columns within the hypothetical organization of the PAG. They also indicate a continuous activation of a significant population of neurones in the PAG, i…
Studying hypertension in ocular fundus images using Hausdorff dispersion ordering.
2010
Retinal arterial and vein diameters are altered in individuals at risk of cardiovascular events mainly due to high blood pressure. The measurement of retinal vessel diameters has been proved to reflect individuals' vascular health. Dispersion of such measures which are obtained by means of ocular fundus images is a major factor not usually considered in clinical research. In this paper, a method to evaluate if different levels of clinically relevant covariables induce greater dispersion in retinal arterial and vein diameters is proposed. A multivariate dispersion ordering, the Hausdorff dispersion order, is used to compare the level of dispersion in such diameters for different groups of pa…
The Cumulative Effect of Transient Synchrony States on Motor Performance in Parkinson's Disease.
2020
Bursts of beta frequency band activity in the basal ganglia of patients with Parkinson's disease (PD) are associated with impaired motor performance. Here we test in human adults whether small variations in the timing of movement relative to beta bursts have a critical effect on movement velocity and whether the cumulative effects of multiple beta bursts, both locally and across networks, matter.
The nucleosome-remodeling ATPase ISWI is regulated by poly-ADP-ribosylation.
2008
ATP-dependent nucleosome-remodeling enzymes and covalent modifiers of chromatin set the functional state of chromatin. However, how these enzymatic activities are coordinated in the nucleus is largely unknown. We found that the evolutionary conserved nucleosome-remodeling ATPase ISWI and the poly-ADP-ribose polymerase PARP genetically interact. We present evidence showing that ISWI is target of poly-ADP-ribosylation. Poly-ADP-ribosylation counteracts ISWI function in vitro and in vivo. Our work suggests that ISWI is a physiological target of PARP and that poly-ADP-ribosylation can be a new, important post-translational modification regulating the activity of ATP-dependent nucleosome remodel…
Gaming is related to enhanced working memory performance and task-related cortical activity
2017
Gaming experience has been suggested to lead to performance enhancements in a wide variety of working memory tasks. Previous studies have, however, mostly focused on adult expert gamers and have not included measurements of both behavioral performance and brain activity. In the current study, 167 adolescents and young adults (aged 13–24 years) with different amounts of gaming experience performed an n-back working memory task with vowels, with the sensory modality of the vowel stream switching between audition and vision at random intervals. We studied the relationship between self-reported daily gaming activity, working memory (n-back) task performance and related brain activity measured u…