Developmental Maturation (developmental + maturation)

Distribution by Scientific Domains

Selected Abstracts

Developmental maturation of ionotropic glutamate receptor subunits in rat vestibular nuclear neurons responsive to vertical linear acceleration

Suk-King Lai
Abstract We investigated the maturation profile of subunits of ionotropic glutamate receptors in vestibular nuclear neurons that were activated by sinusoidal linear acceleration along the vertical plane. The otolithic origin of Fos expression in these neurons was confirmed as a marker of functional activation when labyrinthectomized and/or stationary control rats contrasted by showing sporadically scattered Fos-labeled neurons in the vestibular nuclei. By double immunohistochemistry for Fos and one of the receptor subunits, otolith-related neurons that expressed either ,-amino-3-hydroxy-5-methyl-4-isoxazole-propionate or N -methyl- d -aspartate subunits were first identified in the medial vestibular nucleus, spinal vestibular nucleus and Group x by postnatal day (P)7, and in the lateral vestibular nucleus and Group y by P9. No double-labeled neurons were found in the superior vestibular nucleus. Within each vestibular subnucleus, these double-labeled neurons constituted ,90% of the total Fos-labeled neurons. The percentage of Fos-labeled neurons expressing the GluR1 or NR2A subunit showed developmental invariance in all subnuclei. For Fos-labeled neurons expressing the NR1 subunit, similar invariance was observed except that, in Group y, these neurons decreased from P14 onwards. For Fos-labeled neurons expressing the GluR2, GluR2/3, GluR4 or NR2B subunit, a significant decrease was found by the adult stage. In particular, those expressing the GluR4 subunit showed a two- to threefold decrease in the medial vestibular nucleus, spinal vestibular nucleus and Group y. Also, those expressing the NR2B subunit showed a twofold decrease in Group y. Taken together, the postsynaptic expression of ionotropic glutamate receptor subunits in different vestibular subnuclei suggests that glutamatergic transmission within subregions plays differential developmental roles in the coding of gravity-related vertical spatial information. [source]

MRI-based morphometric analysis of typical and atypical brain development

David N. Kennedy
Abstract The neuroinformatics landscape in which human brain morphometry occurs has advanced dramatically over the past few years. Rapid advancement in image acquisition methods, image analysis tools and interpretation of morphometric results make the study of in vivo anatomic analysis both challenging and rewarding. This has revolutionized our expectations for current and future diagnostic and investigative work with the developing brain. This paper will briefly cover the methods of morphometric analysis that available for neuroanatomic analysis, and tour some sample results from a prototype retrospective database of neuroanatomic volumetric information. From these observations, issues regarding the anatomic variability of developmental maturation of neuroanatomic structures in both typically and atypically developing populations can be discussed. MRDD Research Reviews 2003;9:155,160. 2003 Wiley-Liss, Inc. [source]

Basic principles of MRI and morphometry studies of human brain development

David N. Kennedy
Magnetic resonance imaging has undergone dramatic development in the past years. This has been paralleled by developments in the tools for extracting quantitative information from these images in support of capturing the anatomic features of brain development in living humans. This has revolutionized our expectations for current and future diagnostic and investigative work with the developing brain. This paper will cover the classes of information that are readily available in the MR image, the mechanisms for extracting quantitative results, and a sample of the application of these types of methods to developmental issues. These applications highlight tissue- and anatomic-based contrasts in the nature and rate of developmental maturation within the brain. This will be followed by a discussion of the emergent themes of developmental science as elucidated by these classes of observation. [source]

Insulin promotes functional induction of silent synapses in differentiating rat neocortical neurons

Daniela Plitzko
Abstract Long-term synaptic plasticity is thought to underlie synaptic reorganization phenomena that occur during neocortical development. Recently, it has been proposed, that the functional induction of AMPA receptors at silent glutamatergic synapses is of major importance in activity-dependent, developmental plasticity. To investigate the mechanisms involved in the developmental regulation of silent synapses, we analysed the functional maturation of the thalamocortical projection in culture. A large proportion of the thalamocortical synapses were functionally silent at an early stage in vitro. During further differentiation, the incidence of silent synapses decreased drastically, indicating a conversion of silent into functional synapses. Chronic blockade of spontaneous network activity by addition of tetrodotoxin to the culture medium strongly impaired this developmental maturation. Moreover, the developmental decline in the proportion of silent synapses was dramatically accelerated by chronic addition of the neurotrophic factor, insulin. This effect of insulin was partly dependent on spontaneous activity. Thus, insulin appears to be involved in the modulation of long-term developmental plasticity at immature glutamatergic synapses. [source]

The developmental change in strategies parents employ to settle young children to sleep, and their relationship to infant sleeping problems, as assessed by a new questionnaire: the Parental Interactive Bedtime Behaviour Scale

Julian Morrell
Abstract The development of a new parental self-report questionnaire, the Parental Interactive Bedtime Behaviour Scale (PIBBS) is described. The PIBBS was designed to capture a wide range of parental behaviours used to settle infants off to sleep. The commonest behaviours employed were giving a feed, talking softly to the child, cuddling in the arms, and stroking. A factor analysis revealed five settling strategies; ,active physical comforting' (e.g. cuddling in arms); ,encouraging infant autonomy' (e.g. leaving to cry); ,movement' (e.g. car rides), ,passive physical comforting' (e.g. standing next to the cot without picking the infant up), and ,social comforting' (e.g. reading a story). Excessive ,active physical comforting' and reduced ,encourage autonomy' strategy use was associated with infant sleeping problems. Regarding developmental change in strategy between 1 and 2 years, the later the onset at which ,encourage autonomy' became the principal strategy used, the more likely that persistent infant sleeping problems would be present. Factors accounting for the change in strategy use over time were: (i) parental adaptation to infant developmental maturation; (ii) the interaction between maternal cognition and strategy, and, to a lesser extent; (iii) the interaction between infant temperament and parental strategy. Copyright 2002 John Wiley & Sons, Ltd. [source]