Search results for "Fetal brain"
showing 8 items of 8 documents
On the growth and form of cortical convolutions
2016
International audience; The rapid growth of the human cortex during development is accompanied by the folding of the brain into a highly convoluted structure1-3. Recent studies have focused on the genetic and cellular regulation of cortical growth4-8, but understanding the formation of the gyral and sulcal convolutions also requires consideration of the geometry and physical shaping of the growing brain9-15. To study this, we use magnetic resonance images to build a 3D-printed layered gel mimic of the developing smooth fetal brain; when immersed in a solvent, the outer layer swells relative to the core, mimicking cortical growth. This relative growth puts the outer layer into mechanical com…
Epigenetic dysregulation in the developing Down syndrome cortex
2016
Using Illumina 450K arrays, 1.85% of all analyzed CpG sites were significantly hypermethylated and 0.31% hypomethylated in fetal Down syndrome (DS) cortex throughout the genome. The methylation changes on chromosome 21 appeared to be balanced between hypo- and hyper-methylation, whereas, consistent with prior reports, all other chromosomes showed 3–11 times more hyper- than hypo-methylated sites. Reduced NRSF/REST expression due to upregulation of DYRK1A (on chromosome 21q22.13) and methylation of REST binding sites during early developmental stages may contribute to this genome-wide excess of hypermethylated sites. Upregulation of DNMT3L (on chromosome 21q22.4) could lead to de novo methyl…
Potential pitfalls in fetal neurosonography
2005
Objective To present anatomic variants of the fetal brain and artifacts related to scanning techniques that could be misinterpreted as abnormalities on prenatal neurosonographic studies. Methods The findings were derived from fetal neurosonographic studies performed routinely from 16 to 36 weeks' gestation during the last 3 years, supervised by a sonologist specialized in neonatal cranial sonography. Results The pitfalls were divided into three groups: brain parenchyma, ventricular system and choroid plexus. We provide images of these pseudolesions and clues to their differentiation from true brain pathology. Conclusions Knowledge of misleading images seen on fetal neurosonographic studies …
Changes in Cerebral Amino Acid Transport During Development
1976
The transport of metabolites to and from the central nervous system is of considerable interest. To a greater extent than most other tissues, central nervous system tissue invitro takes up amino acids to well above their concentrations in the incubation medium. Presumably the transport systems responsible for this uptake and for efflux invitro are also those responsible for transport between brain cells in living animals2.
Isolation and differential expression of two isoforms of the ROBO2/Robo2 axon guidance receptor gene in humans and mice.
2006
AbstractExpression of Robo receptor molecules is important for axon guidance across the midline of the mammalian central nervous system. Here we describe novel isoform a of human ROBO2, which is initially strongly expressed in the fetal human brain but thereafter only weakly expressed in adult brain and a few other tissues. The known isoform b of ROBO2 shows a more or less ubiquitous expression pattern, suggesting diverse functional roles. The genomic structure and distinct expression patterns of Robo2a and Robo2b have been conserved in the mouse, but in contrast to human ROBO2a mouse Robo2a is also abundant in adult brain. Exons 1 and 2 of human ROBO2a lie in an inherently unstable DNA seg…
An anatomical fetal brain structure and a normal variant mimicking anomalies on routine neurosonographic imaging: report of two cases
2004
We present two cases in which an anatomical structure, the calcar avis, and a normal variant, a bifid choroid plexus, mimicked abnormalities on routine prenatal ultrasound examination. To the best of our knowledge these pitfalls have only been described in neonates. A familiarity with these false images is important to avoid erroneous diagnoses.