213 research outputs found
Starting at the endophenotype: A role for alpha-CaMKII in schizophrenia?
Using an endophenotype-driven screen, a new study finds that α-calcium/calmodulin kinase II mutant mice exhibit a range of behavioral abnormalities related to schizophrenia. Perhaps most strikingly, this cluster of schizophrenia-related endophenotypes was associated with abnormal neurogenesis in the adult hippocampus, raising the possibility that disrupted adult neurogenesis lies at the core of this and other psychiatric disorders
Auditory conditioned stimulus presentation during NREM sleep impairs fear memory in mice
Externally manipulating memories by presenting conditioned stimuli (CS) during sleep is a new approach to investigating memory processing during sleep. However, whether presenting a CS during REM or NREM sleep enhances or extinguishes fear memory has not been clearly delineated. In this study, mice underwent trace fear conditioning consisting of an auditory CS paired with a foot shock, and the auditory CS was re-presented during subsequent REM or NREM sleep. Mice that received auditory cueing during NREM but not REM sleep showed impaired fear memory upon later presentation of the auditory CS. These findings have implications for the use of cueing during sleep and advance our understanding of the role of REM and NREM sleep in memory consolidation
Holes in the valence band of superconducting boron-doped diamond film studied by soft X-ray absorption and emission spectroscopy
Carbon- and boron-2 states of superconducting and non-superconducting
boron-doped diamond samples are measured using soft X-ray emission and
absorption spectroscopy. For the superconducting sample, a large density of
hole states is observed in the valence band in addition to the states in the
impurity band. The hole states in the valence band is located at about 1.3 eV
below the valence band maximum regardless of the doping level, which cannot be
interpreted within a simple rigid band model. Present experimental results,
combined with the first principles calculations, suggest that superconductivity
is to be attributed to the holes in the valence band.Comment: 4 pages, 4 figure
Galectin-1 is expressed in early-type neural progenitor cells and down-regulates neurogenesis in the adult hippocampus
<p>Abstract</p> <p>Background</p> <p>In the adult mammalian brain, neural stem cells (NSCs) proliferate in the dentate gyrus (DG) of the hippocampus and generate new neurons throughout life. A multimodal protein, Galectin-1, is expressed in neural progenitor cells (NPCs) and implicated in the proliferation of the NPCs in the DG. However, little is known about its detailed expression profile in the NPCs and functions in adult neurogenesis in the DG.</p> <p>Results</p> <p>Our immunohistochemical and morphological analysis showed that Galectin-1 was expressed in the type 1 and 2a cells, which are putative NSCs, in the subgranular zone (SGZ) of the adult mouse DG. To study Galectin-1's function in adult hippocampal neurogenesis, we made <it>galectin-1 </it>knock-out mice on the C57BL6 background and characterized the effects on neurogenesis. In the SGZ of the <it>galectin-1 </it>knock-out mice, increased numbers of type 1 cells, DCX-positive immature progenitors, and NeuN-positive newborn neurons were observed. Using triple-labeling immunohistochemistry and morphological analyses, we found that the proliferation of the type-1 cells was increased in the SGZ of the <it>galectin-1 </it>knock-out mice, and we propose that this proliferation is the mechanism for the net increase in the adult neurogenesis in these knock-out mice DG.</p> <p>Conclusions</p> <p>Galectin-1 is expressed in the neural stem cells and down-regulates neurogenesis in the adult hippocampus.</p
A simple optimization can improve the performance of single feature polymorphism detection by Affymetrix expression arrays
<p>Abstract</p> <p>Background</p> <p>High-density oligonucleotide arrays are effective tools for genotyping numerous loci simultaneously. In small genome species (genome size: < ~300 Mb), whole-genome DNA hybridization to expression arrays has been used for various applications. In large genome species, transcript hybridization to expression arrays has been used for genotyping. Although rice is a fully sequenced model plant of medium genome size (~400 Mb), there are a few examples of the use of rice oligonucleotide array as a genotyping tool.</p> <p>Results</p> <p>We compared the single feature polymorphism (SFP) detection performance of whole-genome and transcript hybridizations using the Affymetrix GeneChip<sup>® </sup>Rice Genome Array, using the rice cultivars with full genome sequence, <it>japonica </it>cultivar Nipponbare and <it>indica </it>cultivar 93-11. Both genomes were surveyed for all probe target sequences. Only completely matched 25-mer single copy probes of the Nipponbare genome were extracted, and SFPs between them and 93-11 sequences were predicted. We investigated optimum conditions for SFP detection in both whole genome and transcript hybridization using differences between perfect match and mismatch probe intensities of non-polymorphic targets, assuming that these differences are representative of those between mismatch and perfect targets. Several statistical methods of SFP detection by whole-genome hybridization were compared under the optimized conditions. Causes of false positives and negatives in SFP detection in both types of hybridization were investigated.</p> <p>Conclusions</p> <p>The optimizations allowed a more than 20% increase in true SFP detection in whole-genome hybridization and a large improvement of SFP detection performance in transcript hybridization. Significance analysis of the microarray for log-transformed raw intensities of PM probes gave the best performance in whole genome hybridization, and 22,936 true SFPs were detected with 23.58% false positives by whole genome hybridization. For transcript hybridization, stable SFP detection was achieved for highly expressed genes, and about 3,500 SFPs were detected at a high sensitivity (> 50%) in both shoot and young panicle transcripts. High SFP detection performances of both genome and transcript hybridizations indicated that microarrays of a complex genome (e.g., of <it>Oryza sativa</it>) can be effectively utilized for whole genome genotyping to conduct mutant mapping and analysis of quantitative traits such as gene expression levels.</p
Congenital prepubic sinus: A case report and review of the literature
AbstractCongenital prepubic sinus (CPS) is an extremely rare anomaly, which is often associated with purulent discharge from a midline opening overlying the pubis. CPS was first described by Campbell et al. in 1987 and they suggested that it might represent a variation in normal embryological development. Several theories have been proposed regarding the pathogenesis of CPS. However, the etiology of CPS is still unclear because the anatomical and pathological features of CPS often differ from each other. We report a case of CPS and review the literature to improve the global understanding of CPS
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