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Degeneration of noradrenergic neurons in the locus coeruleus and loss of fiber terminals in the neocortical and hippocampal target regions represent prominent and early features of Alzheimer’s disease, however, whether these events are causally linked to cognitive decline in Alzheimer’s disease is still unclear. In the present study, the noradrenergic contribution to the regulation of hippocampus-dependent spatial learning and memory was investigated. Postnatal day 4 rats underwent selective immunolesioning of hippocampal noradrenergic afferents and, 4 days later, the bilateral intrahippocampal implantation of locus coeruleus noradrenergic neuroblasts. Starting from 4 weeks and up to about 9 months postsurgery, sensory-motor and spatial navigation abilities were evaluated, followed by postmortem tissue analyses. All animals in the Control, Lesion, and Lesion+Transplant groups exhibited normal sensory-motor function and were equally efficient in the reference memory version of the water maze task, whereas working memory abilities were seen consistently impaired in the Lesion-only rats. Notably, the noradrenergic reinnervation promoted by the grafted progenitors reinstated a fairly normal working memory performance, suggesting a primary role for coeruleo-hippocampal noradrenergic inputs in the maintenance of specific aspects of cognition.

MPEG-4 gives the opportunity to describe the scenes of a motion picture directly through XMT-A and XMT-O: two “high level languages” that are XML based. Moreover MPEG-4 allows (and defines) the opportunities for video streaming. This makes this standard appealing for the conversion of Impress or PowerPoint presentations and also for other e-learning applications because it offers the possibility of publishing the converted presentations on streaming servers (as for example the Darwin server). In this paper we exploit those possibilities by implementing an Impress extension that translates an electronic presentation to XMT-O, so to be finally “compiled” for MPEG-4 conversion, and a streaming architecture for e-learning.