Developmental medicine and child neurology
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Dev Med Child Neurol · May 2006
ReviewProlonged coexistence of transient and permanent circuitry elements in the developing cerebral cortex of fetuses and preterm infants.
The aim of this paper is to evaluate correlative magnetic resonance imaging (MRI) and histological parameters of development of cortical afferents during pathfinding and target selection in transient fetal cerebral laminas in human fetuses and preterm infants. The transient fetal subplate zone, situated between the fetal white matter (i.e. intermediate zone) and the cortical plate, is the crucial laminar compartment for development of thalamocortical and corticocortical afferents. The prolonged coexistence of transient (endogenously active) and permanent (sensory-driven) circuitry within the transient fetal zones is a salient feature of the fetal and preterm cortex; this transient circuitry is the substrate of cerebral functions in preterm infants. ⋯ Hypoxic-ischaemic lesions of periventricular crossroads are the substrate for motor, sensory, and cognitive deficits after focal periventricular leukomalacia (PVL). Lesions of distal portions of the white matter and the subplate zone are the substrate for diffuse PVL. The neuronal elements in transient fetal zones form a developmental potential for plasticity after perinatal cerebral lesions.