No abstract

Over the past several decades, significant advances have been made in our understanding of the basic stages and mechanisms of mammalian brain development. Studies elucidating the neurobiology of brain development span the levels of neural organization from the macroanatomic, to the cellular, to the molecular. Together this large body of work provides a picture of brain development as the product of a complex series of dynamic and adaptive processes operating within a highly constrained, genetically organized but constantly changing context. The view of brain development that has emerged from the developmental neurobiology literature presents both challenges and opportunities to psychologists seeking to understand the fundamental processes that underlie social and cognitive development, and the neural systems that mediate them. This chapter is intended to provide an overview of some very basic principles of brain development, drawn from contemporary developmental neurobiology, that may be of use to investigators from a wide range of disciplines.

SUMMARYIn the present study using magnetic resonance imaging (MRI), age changes in the morphology of the cerebral cortex, greatest in the frontal and parietal convexities, were observed during adolescence. Results suggest that increases in cerebrospinal fluid (CSF) within the sulci of these cortical regions accompany grey matter decreases. Smaller reductions in volume are also observed in subcortical grey matter nuclei. These apparent grey matter volume reductions presumably reflect processes of late brain maturation. The changes may be related to decreasing neural plasticity.

Cystinosis is caused by mutations in the CTNS gene (17p13.2), which encodes for a lysosomal cystine/proton symporter termed cystinosin. It is the most common cause of inherited renal Fanconi syndrome in young children. Because of its rarity, the diagnosis and specific treatment of cystinosis are frequently delayed, which has a significant impact on the overall prognosis. In this document, we have summarized expert opinions on several aspects of the disease to improve knowledge and provide guidance for diagnosis and treatment.

The developing brain has the capacity for a great deal of plasticity. A number of investigators have demonstrated that intellectual and language skills may be in the normal range in children following unilateral perinatal stroke. Questions have been raised, however, about whether these skills can be maintained at the same level as the brain matures. This study aimed to examine the stability of intellectual, academic and language functioning during development in children with perinatal stroke, and to resolve the inconsistencies raised in previous studies. Participants were 29 pre-school to school-age children with documented unilateral ischaemic perinatal stroke and 24 controls. Longitudinal testing of intellectual and cognitive abilities was conducted at two time points. Study 1 examined IQ, academic skills and language functions using the same test version over the test-retest interval. Study 2 examined IQ over a longer test-retest interval (pre-school to school-age), and utilized different test versions. This study has resulted in important new findings. There is no evidence of decline in cognitive function over time in children with perinatal unilateral brain damage. These results indicate that there is sufficient ongoing plasticity in the developing brain following early focal damage to result in the stability of cognitive functions over time. Also, the presence of seizures limits plasticity such that there is not only significantly lower performance on intellectual and language measures in the seizure group (Study 1), but the course of cognitive development is significantly altered (as shown in Study 2). This study provides information to support the notion of functional plasticity in the developing brain; yields much-needed clarification in the literature of prognosis in children with early ischaemic perinatal stroke; provides evidence that seizures limit plasticity during development; and avoids many of the confounds in prior studies. A greater understanding of how children with ischaemic perinatal stroke fare over time is particularly important, as there has been conflicting information regarding prognosis for this population. It appears that when damage is sustained very early in brain development, cerebral functional reorganization acts to sustain a stable rate of development over time.