This book contains updated reviews and original research work on Down Syndrome focussing on brandnew results in neurobiology, in particular results on gene hunting (subtractive hybridization, differential display) and neurochemistry. The book provides new data such as a subtractive library of Down Syndrome brain showing cDNAs that are overexpressed or downregulated and can be regarded as a source for further research on the preliminary transcriptional data given. A 2D-electrophoretic map of human brain proteins including Down Syndrome brain protein expression established by in-gel-digestion of spots with subsequent MALDI-identification provides the scientific basis for protein work to the neuroscientist. Altogether, the book provides a series of new candidate genes possibly involved in Down Syndrome neurobiology, tools for neuroscience studies on Down Syndrome brain thus serving as a manual and updated views and aspects on Down Syndrome pathobiology.

Down syndrome (DS) is the most common example of neurogenetic aneuploid disorder leading to mental retardation. In most cases, DS results from an extra copy of chromosome 21 (HSA21) producing deregulated gene expression in brain that gives raise to subnormal intellectual functioning. The topic of this volume is of broad interest for the neuroscience community, because it tackles the concept of neurogenomics, that is, how the genome as a whole contributes to a neurodevelopmental cognitive disorders, such as DS, and thus to the development, structure and function of the nervous system. This volume of Progress in Brain Research discusses comparative genomics, gene expression atlases of the brain, network genetics, engineered mouse models and applications to human and mouse behavioral and cognitive phenotypes. It brings together scientists of diverse backgrounds, by facilitating the integration of research directed at different levels of biological organization, and by highlighting translational research and the application of the existing scientific knowledge to develop improved DS treatments and cures. Leading authors review the state-of-the-art in their field of investigation and provide their views and perspectives for future research Chapters are extensively referenced to provide readers with a comprehensive list of resources on the topics covered All chapters include comprehensive background information and are written in a clear form that is also accessible to the non-specialist

"Advances in Down Syndrome Research” represents updated research in several areas of Down Syndrome (DS). A new promising animal model of DS is reported and this opens new opportunities to study pathomechanisms and pharmacological approaches as it is more than difficult to carry out studies in humans and the clinical features are highly variable. In terms of biology, cell cycle and stem cell studies and in terms of biochemistry, relevance of studies on a specific protein kinase, channels, transporters, superoxide dismutase, antioxidant system, chromosome assembly factor and other important biological structures are provided. And again, the gene dosage hypothesis is addressed and although the vast majority of chromosome 21 gene products is unchanged in fetal DS brain, a few specific chromosome 21 encoded structures including transcription factors are indeed overexpressed although findings in fetal DS are different from those in adult DS brain when Alzheimer-like neuropathology supervenes.

When we worked on Down Syndrome brain in the past we have been focus ing on adult brain. This was a major step forwards as most work on Down Syndrome was carried out on fibroblasts or other tissues and, moreover, we introduced proteomics to identify and quantify brain protein expression. We considered evaluation of brain protein expression in Down Syndrome brain by and by more important than gene hunting at the nucleic acid level realiz ing the long unpredictable way from RNA to protein. The availability of fetal samples along with the proteomic appproach stimulated and reinforced studies on Down Syndrome brain. And indeed, it was found out that some observations on aberrant protein expression in adult Down Syndrome brain could not be verified in the fetal samples indi cating that neurodegeneration in adult Down Syndrome brain may have been responsible rather than trisomy 21. Using brains from the early second trimester of gestation led to the generation of a series of clues for the under standing of aberrant wiring of the brain in Down Syndrome and enabled the determination of altered key functions in early life; e. g. undetectably low drebrin was observed in Down Syndrome cortex, an integral constituent and marker for dendritic spines, main effectors of cross-talk between neurons. In addition, evaluation of the nature of the neuronal deficits in terms of neuro transmission markers could be established as well as neuronal density in fetal Down Syndrome cortex.

In recent years, the molecular analysis of chromosome 21 has progressed so rapidly that the current level of sophistication in understanding the organization of its genes and DNA sequences perhaps exceeds that of any other chromosome. This book explores the fundamental nature of this condition's pathology as related to the structure and expression of genes that are known to be critical in the development of Down Syndrome. It recounts the impressive advances made toward a complete physical mapping of chromosome 21. It also discusses how individual genes in this chromosome have been isolated and their effects relevant to aspects of Down Syndrome are being studied in both cellular and in vivo models. This text provides a comprehensive account of the most up-to-date research in this area, and offers a general overview of the advances in molecular analysis techniques that are revolutionizing the entire field of chromosomal mapping.