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Small Brain (small + brain)
Selected AbstractsIn the Cockpit of the FlyGERMAN RESEARCH, Issue 1 2003Martin Egelhaaf Prof. Dr. Small brains can completely outclass large ones in their performance. Thus the fly has proved to be an outstanding model system for image processing in the brain [source] Neuropathology of Rett syndromeDEVELOPMENTAL DISABILITIES RESEARCH REVIEW, Issue 2 2002Dawna Duncan Armstrong Abstract Rett Syndrome is unlike any other pediatric neurologic disease, and its clinical-pathologic correlation can not be defined with standard histology techniques. Based on hypotheses suggested by careful clinical observations, the nervous system of the Rett child has been explored utilizing morphometry, golgi preparations, computerized tomography, magnetic resonance imaging, chemistry, immunocytochemistry, autoradiography, and molecular biologic techniques. From these many perspectives we conclude that Rett syndrome is not a typical degenerative disorder, storage disorder, nor the result of gross malformation, infectious or neoplastic processes. There remain regions of the brain that have not been studied in detail but the available data suggest that the neuropathology of Rett syndrome can be summarized as follows: the Rett brain is small for the age and the height of the patient; it does not become progressively smaller over three to four decades; it has small dendritic trees in pyramidal neurons of layers III and V in selected lobes (frontal, motor, and temporal); it has small neurons with an increased neuronal packing density; it has an immature expression of microtubular protein-2 and cyclooxygenase; it exhibits a changing pattern of neurotransmitter receptors with an apparent reduction in many neurotransmitters, possibly contributing to some symptomatology. A mutation in Mecp2 causes this unique disorder of brain development. Neuronal mosaicism for normal and mutated Mecp2 produces a consistent phenotype in the classic female patient and a small brain with some preserved islands of function, but with an inability to support hand use and speech. This paper summarizes our current observations about neuropathology of Rett syndrome. MRDD Research Reviews 2002;8:72,76. © 2002 Wiley-Liss, Inc. [source] The fellowship of the hobbit: the fauna surrounding Homo floresiensisJOURNAL OF BIOGEOGRAPHY, Issue 6 2010Hanneke J. M. Meijer Abstract The Late Pleistocene Flores fauna shows a pattern observed on many other islands. It is neither aberrant nor exclusive, but the result of non-random selective forces acting upon an impoverished and disharmonic insular fauna. By comparing the Flores vertebrate fauna with other fossil insular biotas, it is apparent that the evolution of Homo floresiensis is part of a general pattern affecting all the inhabitants of Pleistocene Flores. Vertebrate evolution on Flores appears to have been characterized by phylogenetic continuity, low species richness and a disharmonic fauna. All three aspects stem from the isolated position of the island and have resulted in the distinct morphological characteristics of the Flores fauna. Evidence reviewed herein shows that features exhibited by H. floresiensis, such as small stature, a small brain, relatively long arms, robust lower limbs and long feet, are not unique, but are shared by other insular taxa. Therefore, the evolution of H. floresiensis can be explained by existing models of insular evolution and followed evolutionary pathways similar to those of the other terrestrial vertebrates inhabiting Pleistocene Flores. [source] STIL on my small brain: a new gene for microcephalyCLINICAL GENETICS, Issue 6 2009RA Kumar No abstract is available for this article. [source] Why there is better evidence for culture in fish than chimpanzeesJOURNAL OF FISH BIOLOGY, Issue 2003K. N. Laland Fish have comparatively small brains and are not renowned for their intelligence. Yet a series of laboratory experiments on the guppy reveals that they can be surprisingly good at learning from each other, and that social learning processes can mediate behavioural traditions analogous to the tool using traditions of different populations of chimpanzees. Transmission chain experiments have established that arbitrary and even maladaptive information can be socially transmitted among shoals of fish. Studies of behavioural innovation in guppies are strikingly consistent with findings of equivalent studies in primates. There are strong sex differences in innovatory tendencies and social learning abilities in guppies, which also parallel observations of primates. These studies suggest that the adage ,necessity is the mother of invention' may be a characteristic feature of animal innovation. When considered in combination with the findings of transfer experiments carried out on natural populations of fish, it becomes apparent that fish are an excellent model system for studies of animal social learning and culture. [source] | |||||||||||||