Search results for " Mapping"
showing 10 items of 1411 documents
Reading for meaning in dyslexic and young children : distinct neural pathways but common endpoints
2009
Developmental dyslexia is a highly prevalent and specific disorder of reading acquisition characterised by impaired reading fluency and comprehension. We have previously identified fMRI- and ERP-based neural markers of impaired sentence reading in dyslexia that indicated both deviant basic word processing and deviant semantic incongruency processing. However, it remained unclear how specific these impairments are for dyslexia, as they occurred when children with dyslexia (DYS) were compared to chronological age-matched controls (CA) who also differ in the amount of reading experience. Adding a younger control group at a similar reading level (RL) as the dyslexic group, we examined here whic…
The human X chromosome is enriched for germline genes expressed in premeiotic germ cells of both sexes.
2006
The role of X-chromosomal genes in spermatogenesis has been subject to a number of studies in different organisms. Recently, it was proposed that the X chromosome has a predominant role in premeiotic stages of mammalian spermatogenesis. We analyzed the expression of a representative set of 17 X-linked and 48 autosomal germline-restricted genes in different stages of human germ cell development. In accordance with data from other species, we show that the human X chromosome is indeed significantly enriched for genes activated in premeiotic stages of spermatogenesis. In contrast to recent studies, however, we found that expression of these genes is not restricted to spermatogenesis, but is ac…
USH3A transcripts encode clarin-1, a four-transmembrane-domain protein with a possible role in sensory synapses.
2002
Usher syndrome type 3 (USH3) is an autosomal recessive disorder characterised by the association of post-lingual progressive hearing loss, progressive visual loss due to retinitis pigmentosa and variable presence of vestibular dysfunction. Because the previously defined transcripts do not account for all USH3 cases, we performed further analysis and revealed the presence of additional exons embedded in longer human and mouse USH3A transcripts and three novel USH3A mutations. Expression of Ush3a transcripts was localised by whole mount in situ hybridisation to cochlear hair cells and spiral ganglion cells. The full length USH3A transcript encodes clarin-1, a four-transmembrane-domain protein…
FDG-PET mapping the brain substrates of visuo-constructive processing in Alzheimer´s disease
2010
The anatomical basis of visuo-constructive impairment in AD is widely unexplored. FDG-PET can be used to determine functional neuronal networks underlying specific cognitive performance in the human brain. In the present study, we determined the pattern of cortical metabolism that was associated with visuo-constructive performance in AD. We employed two widely used visuo-constructive tests that differ in their demand on visual perception and processing capacity. Resting state FDG-PET scans were obtained in 29 probable AD patients, and cognitive tests were administered. We made a voxel-based regression analysis of FDG uptake to scores in visual test performance, using the SPM5 software. Perf…
Genetic and biochemical characterization of little isoxanthopterin (lix), a gene controlling dihydropterin oxidase activity in Drosophila melanogaste…
1991
Dihydropterin oxidase catalyses the oxidation of 7,8-dihydropteridines into their fully oxidized products, and is involved in the biosynthesis of isoxanthopterin. Fifteen Drosophila melanogaster mutants, selected for their low pterin and isoxanthopterin content, were assayed for dihydropterin oxidase activity. The activity was around 100% in most mutants tested, slightly reduced in red, g and dke, and undetectable in lix. In flies carrying various doses of the lix+ allele, a correlation was found between enzyme activity and the number of lix+ copies in the genome. The results suggest that lix is the structural gene for the dihydropterin oxidase enzyme. Isoxanthopterin was quantitated in str…
Deletion of the Hunter gene and both DXS466 and DXS304 in a patient with mucopolysaccharidosis type II.
1992
Hunter syndrome is an X-linked mucopoly-saccharidosis due to deficiency of the lysosomal enzyme iduronate-2-sulfatase (IDS). A cDNA clone containing the entire coding region of the human IDS gene, mapped in Xq28, has been used as molecular probe to study a patient with Hunter syndrome. A submicroscopic deletion has been detected that spans the IDS gene as well as DXS466 and DXS304, 2 loci mapped probably not more than 900 kb from the IDS locus. A detailed clinical description of the patient is provided and his phenotype is compared to that of other patients with IDS deletion described recently. By following the segregation of a restriction fragment length polymorphism at the IDS locus in th…
Gene diagnosis and carrier detection in Hunter syndrome by the iduronate-2-sulphatase cDNA probe.
1992
Hunter disease (McKusick 309900) is an X-chromosomal mucopolysaccharidosis due to deficiency of the lysosomal enzyme iduronate-2-sulphatase (IDS; EC 3.1.6.13). Diagnosis is based on both the typical clinical features of patients and the lack/reduction of IDS activity. Female carriers show no symptoms of the disease. In the past, several different assays were elaborated for measuring enzyme activity in carriers but none of them proved to be suitable for detecting heterozygotes reliably (Zlotogora and Bach 1984)
Molecular analysis in patients with mucopolysaccharidosis type II suggests that DXS466 maps within the Hunter gene
1993
Hunter disease is an X-linked mucopolysaccharidosis caused by deficiency of the lysosomal enzyme iduronate-2-sulfatase (IDS). Using the IDS cDNA and DNA probes corresponding to loci flanking the IDS locus, we performed molecular genetic studies in two patients with Hunter syndrome. An interstitial deletion spanning the middle part of the IDS gene was found in the first patient. The second patient carries a gross gene rearrangement that can be detected after HindIII or EcoRI digestion of genomic DNA, and is similar to that found recently in seven unrelated Hunter patients. Our data suggest that the structural aberration observed is a partial intragenic inversion. As the same altered hybridiz…
Fractionating auditory priors: A neural dissociation between active and passive experience of musical sounds
2019
Learning, attention and action play a crucial role in determining how stimulus predictions are formed, stored, and updated. Years-long experience with the specific repertoires of sounds of one or more musical styles is what characterizes professional musicians. Here we contrasted active experience with sounds, namely long-lasting motor practice, theoretical study and engaged listening to the acoustic features characterizing a musical style of choice in professional musicians with mainly passive experience of sounds in laypersons. We hypothesized that long-term active experience of sounds would influence the neural predictions of the stylistic features in professional musicians in a distinct…
Cross-linguistic variation in the neurophysiological response to semantic processing: Evidence from anomalies at the borderline of awareness
2014
The N400 event-related brain potential (ERP) has played a major role in the examination of how the human brain processes meaning. For current theories of the N400, classes of semantic inconsistencies which do not elicit N400 effects have proven particularly influential. Semantic anomalies that are difficult to detect are a case in point ("borderline anomalies", e.g. "After an air crash, where should the survivors be buried?"), engendering a late positive ERP response but no N400 effect in English (Sanford, Leuthold, Bohan, & Sanford, 2011). In three auditory ERP experiments, we demonstrate that this result is subject to cross-linguistic variation. In a German version of Sanford and colleagu…