Brain-derived neurotrophic factor stimulates energy metabolism in developing cortical neurons.

Brain-derived neurotrophic factor (BDNF) promotes the biochemical and morphological differentiation of selective populations of neurons during development. In this study we examined the energy requirements associated with the effects of BDNF on neuronal differentiation. Because glucose is the preferred energy substrate in the brain, the effect of BDNF on glucose utilization was investigated in developing cortical neurons via biochemical and imaging studies. Results revealed that BDNF increases glucose utilization and the expression of the neuronal glucose transporter GLUT3. Stimulation of glucose utilization by BDNF was shown to result from the activation of Na+/K+-ATPase via an increase in Na+ influx that is mediated, at least in part, by the stimulation of Na+-dependent amino acid transport. The increased Na+-dependent amino acid uptake by BDNF is followed by an enhancement of overall protein synthesis associated with the differentiation of cortical neurons. Together, these data demonstrate the ability of BDNF to stimulate glucose utilization in response to an enhanced energy demand resulting from increases in amino acid uptake and protein synthesis associated with the promotion of neuronal differentiation by BDNF

A critical role for system A amino acid transport in the regulation of dendritic development by brain-derived neurotrophic factor (BDNF).

Dendritic development is essential for the establishment of a functional nervous system. Among factors that control dendritic development, brain-derived neurotrophic factor (BDNF) has been shown to regulate dendritic length and complexity of cortical neurons. However, the cellular and molecular mechanisms that underlie these effects remain poorly understood. In this study, we examined the role of amino acid transport in mediating the effects of BDNF on dendritic development. We show that BDNF increases System A amino acid transport in cortical neurons by selective up-regulation of the sodium-coupled neutral amino acid transporter (SNAT)1. Up-regulation of SNAT1 expression and System A activity is required for the effects of BDNF on dendritic growth and branching of cortical neurons. Further analysis revealed that induction of SNAT1 expression and System A activity by BDNF is necessary in particular to enhance synthesis of tissue-type plasminogen activator, a protein that we demonstrate to be essential for the effects of BDNF on cortical dendritic morphology. Together, these data reveal that stimulation of neuronal differentiation by BDNF requires the up-regulation of SNAT1 expression and System A amino acid transport to meet the increased metabolic demand associated with the enhancement of dendritic growth and branching

Investigating persuasive writing by 9–11 year olds

Within research into children's persuasive writing, relatively little work has been done on the writing of advertisements, how such writing develops in the primary school years and the textual features that help to secure this development. Framed within rhetoric, writing and linguistics, an exploratory study was undertaken in which a standardised task and a repeat-measures design were used to investigate the writing of an advertisement by 112 nine–ten year old pupils from two English Local Authorities, in the spring term and again a year later. The scripts were first rated for five generic constituents of writing using the standardised task guidelines. The scripts were then rated for the use of specific textual features of advertisements. All constituents, and many textual features, showed increased use across the sample as a whole, even though further analysis showed that some children who had used certain features in Year 5 had not used them in Year 6. Qualitative analysis revealed common features within attainment sub-groups in content, language use and overall effectiveness of the writing. There were indications that, if appropriately supported, experience of advertisement writing could contribute to children’s abilities in tackling other forms of persuasive writing

A Neural Model of Human Object Recognition Development

Abstract. The human capability of recognizing objects visually is here held to be a function emerging as result of interactions between epigenetic influences and basic neural plasticity mechanisms. The model here proposed simulates the development of the main neural processes of the visual system giving rise to the higher function of recognizing objects. It is a hierarchy of artificial neural maps, mainly based on the LISSOM architecture, achieving self-organization through simulated intercortical lateral connections.