Neurological Development (neurological + development)

Distribution by Scientific Domains

Selected Abstracts

An essential role for the H218/AGR16/Edg-5/LPB2 sphingosine 1-phosphate receptor in neuronal excitability

A. John MacLennan
Abstract A wealth of indirect data suggest that the H218/AGR16/Edg-5/LPB2 sphingosine 1-phosphate (S1P) receptor plays important roles in development. In vitro, it activates several forms of development-related signal transduction and regulates cellular proliferation, differentiation and survival. It is expressed during embryogenesis, and mutation of an H218 -like gene in zebrafish leads to profound defects in embryonic development. Nevertheless, the in vivo functions served by H218 signalling have not been directly investigated. We report here that mice in which the H218 gene has been disrupted are unexpectedly born with no apparent anatomical or physiological defects. In addition, no abnormalities were observed in general neurological development, peripheral axon growth or brain structure. However, between 3 and 7 weeks of age, H218,/, mice have seizures which are spontaneous, sporadic and occasionally lethal. Electroencephalographic abnormalities were identified both during and between the seizures. At a cellular level, whole-cell patch-clamp recordings revealed that the loss of H218 leads to a large increase in the excitability of neocortical pyramidal neurons. Therefore, H218 plays an essential, unanticipated and functionally important role in the proper development and/or mediation of neuronal excitability. [source]

Protein tyrosine phosphatase ,-deficient mice show aberrant cytoarchitecture and structural abnormalities in the central nervous system

Karen Meathrel
Abstract Protein tyrosine phosphatase , (PTP,) is a member of the LAR family of receptor tyrosine phosphatases and is highly expressed in the nervous system during development. PTP, is homologous to the Drosophila DLAR, which plays a key role in the targeting of axonal growth cones in flies. We have previously inactivated the Ptprs gene in mice and demonstrated stunted growth, developmental delays, and neurological and neuroendocrine defects in the PTP, null animals. Here, we mapped the expression of the lac-Z reporter gene included in the knockout cassette and surveyed the development of the CNS in these mice after birth. The strongest expression of ,-galactosidase (PTP,) was observed in the hippocampus, cerebral cortex, olfactory bulbs, and subependymal layer. Our analysis reveals hippocampal dysgenesis, reductions in the thickness of the corpus callosum and the cerebral cortex, and late expression of the growth-associated protein 43 (GAP-43) in the knockout animals. Architectural abnormalities in the brain and spinal cord were confirmed by immunoreactivity to neurofilament and glial fibrillary acidic protein (GFAP) antibodies. Several of these neural abnormalities were corrected with age, suggesting a delay in neurological development related to the knockout of the Ptprs gene. These data suggest that PTP, is likely involved in neurogenesis, axonal growth, and axonal pathfinding in the maturation of the mammalian CNS. 2002 Wiley-Liss, Inc. [source]

A Tale of Two Cases: Lessons for Education From the Study of Two Boys Living With Half Their Brains

Mary Helen Immordino-Yang
ABSTRACT, In recent years, educators have been looking increasingly to neuroscience to inform their understanding of how children's brain and cognitive development are shaped by their learning experiences. However, while this new interdisciplinary approach presents an unprecedented opportunity to explore and debate the educational implications of neuropsychological research, a good model for this dialogue is lacking. This is in part because relatively little is known about the relationships between cognitive, emotional, and neurological development, in part because of a dearth of research methods designed to rigorously connect issues of learning and development to neuropsychological strengths and weaknesses, and in part because neuropsychological studies are rarely presented in a format that is conducive to meaningful cross-disciplinary dialogue with educators. To begin to address these issues, in this article, I present the complementary cases of Nico and Brooke, two high-functioning adolescents, who have suffered the removal of an entire brain hemisphere (Nico his right and Brooke his left) to control severe epilepsy. Through presenting a neuropsychological study of these rare boys' emotion and affective prosody (vocal intonation) through the developmental lens of an educator, I reinterpret the neuropsychological findings for what they reveal about how the boys leveraged their emotional and cognitive strengths to learn important skills for which they were each missing half of the normally recruited neural hardware. While Nico's and Brooke's results seem on the surface to contradict expectations based on neuropsychological findings with adults, they combine to reveal a compensatory logic that begins to elucidate the active role of the learner as well as the organizing role of emotion in brain development, providing a jumping-off point for discussion between educators and neuroscientists and a model for connecting neuropsychological strengths and weaknesses to learning. [source]

Assessment of cortical gyrus and sulcus formation using magnetic resonance images in small-for-gestational-age fetuses

Seiji Abe
Abstract Objectives The purpose was to compare the development of gyrus and sulcus formation (GSF), an indicator of brain maturation, in small-for-gestational-age (SGA) fetuses using magnetic resonance (MR) imaging, with those of appropriate-for-gestational-age (AGA) fetuses. Methods The 160 infants with a normal neurological outcome were divided into two groups on the basis of their body weight at delivery; 37 SGA infants (Group SGA) and 123 AGA infants (Group AGA). Fetal MR images, which were obtained from 28 to 39 gestational weeks in Group SGA and from 18 to 39 gestational weeks in Group AGA, were classified into the 8 stages of development for GSF established by Abe et al. (2003), and comparison was made between the two groups retrospectively in their neurological development in relation to gestational age. Results In Group SGA, images were classified into stages 3 to 8 (P < 0.001). The gestational age of the cases determined for each stage between Groups SGA and AGA did not differ significantly, with respect to the development of GSF, despite differences in fetal estimated body weights. Conclusion In SGA fetuses, evaluation of fetal GSF using MR images during the third trimester may be useful for predicting neurological prognoses postpartum. Copyright 2004 John Wiley & Sons, Ltd. [source]

Treatment technologies for mercury in soil, waste, and water

REMEDIATION, Issue 1 2007
Martha Otto
Mercury occurs naturally in the environment and can be found in elemental (metallic), inorganic, and organic forms. Modern uses for mercury include chemical manufacturing, thermometers, and lighting (mercury vapor and fluorescent lamps). The chemical and allied products industry group is responsible for the largest quantity of mercury used in the United States. Mercury, particularly the organic methylmercury form, is a potent neurotoxin capable of impairing neurological development in fetuses and young children and of damaging the central nervous system of adults. Mercury regulations span multiple federal and state environmental statutes, as well as multiple agency jurisdictions. In August 2007, the U.S. Environmental Protection Agency's (US EPA's) Office of Superfund Remediation and Technology Innovation (OSRTI) published a report titled "Treatment Technologies for Mercury in Soil, Waste, and Water." The report identifies eight treatment technologies and 57 projects, 50 of which provide performance data. This information can help managers at sites with mercury-contaminated media and generators of mercury-contaminated waste and wastewater to identify proven and effective mercury treatment technologies; screen technologies based on application-specific goals, characteristics, and costs; and apply experiences from sites with similar treatment challenges. This article provides a synopsis of the US EPA report, which is available at 2007 Wiley Periodicals, Inc., [source]

First steps towards effective methods in exploiting high-throughput technologies for the determination of human protein structures of high biomedical value

L. Banci
The EC `Structural Proteomics In Europe' contract is aimed specifically at the atomic resolution structure determination of human protein targets closely linked to health, with a focus on cancer (kinesins, kinases, proteins from the ubiquitin pathway), neurological development and neurodegenerative diseases and immune recognition. Despite the challenging nature of the analysis of such targets, ,170 structures have been determined to date. Here, the impact of high-throughput technologies, such as parallel expression of multiple constructs, the use of standardized refolding protocols and optimized crystallization screens or the use of mass spectrometry to assist sample preparation, on the structural biology of mammalian protein targets is illustrated through selected examples. [source]

Neurodevelopmental outcome and pulmonary morbidity two years after early versus late surfactant treatment: does it really differ?

R Hentschel
Abstract Aim: To investigate whether neurodevelopmental outcome or pulmonary morbidity at age two years might be different after early versus late surfactant treatment in intubated preterm infants with severe respiratory distress syndrome (RDS). Methods: In 185 ex-preterm infants of 27,32 completed weeks of gestation, who were enrolled in a controlled trial of early versus late surfactant treatment (31 19 min vs. 202 80 min, respectively), a standardized follow up of medical history, pulmonary morbidity and neurodevelopmental outcome using the Griffiths scales were carried out. Results: Neurobehavioural and motor development was comparable in both groups, as was medical history and actual morbidity. However, in the early treatment group a delay in the subscale ,personal social' of the Griffiths test and in one ,milestone' of motor development (rolling over from supine to prone) was noticed, and the rate of increased muscular tone was significantly higher. Conclusion: In terms of long-term morbidity or neurological development there is no obvious advantage of an immediate surfactant administration after intubation in preterm infants with RDS. This is in line with our results published earlier on morbidity at discharge, so improvement of gas exchange after intubation can first be awaited before surfactant is indicated. [source]

Thyroid axis dysfunction in patients with Prader-Willi syndrome during the first 2 years of life

Elisa Vaiani
Summary Introduction, Prader-Willi syndrome (PWS) is a genetic disorder caused by the loss of expression of paternally transcribed genes in a highly imprinted region of chromosome 15q11-13. The clinical phenotype has been well characterized, mostly related to hypothalamic dysfunction. Even though central hypothyroidism has been documented in 20,30% of patients with PWS, thyroid function during the first 2 years of life has not been clearly defined. Objective, To evaluate hypothalamic-pituitary-thyroid function in infant PWS patients. Study design, Eighteen patients with PWS, aged 016,2 years, were included in a prospective study. PWS diagnosis was based on clinical features and molecular analysis. Serum total (T) T4, free (F) T4, T3 and thyroid-stimulating hormone (TSH) were evaluated in the patients with PWS included in the study. Serum hormone values were compared to those of a large reference population of the same age. Results, In 13 of 18 patients with PWS (722%), serum TT4 and/or FT4 levels were below the 25th percentile of the reference population, while in only one PWS patient serum T3 was below this cut-off. Conclusion, The results of this study suggest that transient or definitive thyrotropin-releasing hormone (TRH)-TSH thyroid axis dysfunction may frequently be present in infant PWS patients. Paediatricians should be aware of this dysfunction in this critical period of thyroid hormone action on neurological development. [source]