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Cerebral Plasticity (cerebral + plasticity)
Selected AbstractsCerebral plasticity in crossed C7 grafts of the brachial plexus: An fMRI studyMICROSURGERY, Issue 4 2006Jean-Yves Beaulieu M.D. In order to rescue elbow flexion after complete accidental avulsion of one brachial plexus, seven patients underwent a neurotization of the biceps with fibers from the contralateral C7 root. The C7 fibers used for the graft belonged to the pyramidal pathway, which descends from the cerebral hemisphere ipsilateral to the damaged plexus, and which controls extension and abduction of the contralateral arm. After several months of reeducation, a functional magentic resonance imaging study was performed with a 1.5 tesla clinical magnetic resonance scan system, in order to investigate the central neural networks involved in the recovery of elbow flexion. Functional brain images were acquired under four conditions: flexion of each of the two elbows, and imagined flexion of each elbow. Results show that flexion of the neurotized arm is associated with a bilateral network activity. The contralateral cortex originally involved in control of the rescued arm still participates in the elaboration and control of the task through the bilateral premotor and primary motor cortex. The location of the ipsilateral clusters in the primary motor, premotor, supplementary motor area, and posterior parietal areas is similar among patients. The location of contralateral activations within the same areas differs across patients. © 2006 Wiley-Liss, Inc. Microsurgery, 2006. [source] Reduced plasticity of cortical whisker representation in adult tenascin-C-deficient mice after vibrissectomyEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 6 2004Anita Cybulska-Klosowicz Abstract The effect of the extracellular matrix recognition molecule tenascin-C on cerebral plasticity induced by vibrissectomy was investigated with 2-deoxyglucose (2DG) brain mapping in tenascin-C-deficient mice. Unilateral vibrissectomy sparing row C of vibrissae was performed in young adult mice. Two months later, cortical representations of spared row C vibrissae and control row C on the other side of the snout were visualized by [14C]2DG autoradiography. In both wild-type and tenascin-C-deficient mice, cortical representation of the spared row was expanded in all layers of the barrel cortex. However, the effect was significantly more extensive in wild-type animals than in the mutant. Elimination of tenascin-C by genetic manipulation thus reduces the effect of vibrissectomy observed in the somatosensory cortex. No increase in number of fibres in the vibrissal nerve of spared vibrissae was seen, and occurrence of additional nerve to the spared follicle was very rare. Thus, in tenascin-C-deficient mice functional plasticity seems to be impaired within the CNS. [source] Being neurologically human today: Life and science and adult cerebral plasticity (an ethical analysis)AMERICAN ETHNOLOGIST, Issue 1 2010TOBIAS REES ABSTRACT Throughout the 20th century, scientists believed that the adult human brain is fully developed, organized in fixed and immutable function-specific neural circuits. Since the discovery of the profound plasticity of the human brain in the late 1990s, this belief has been thoroughly undermined. In this article, combining ethnographic and historical research, I develop an "ethical analysis" to show that (and in what concrete sense) the emergence of adult cerebral plasticity was a major mutation of the neurologically human,a metamorphosis of the confines within which neuroscience requires all those who live under the spell of the brain to think and live the human. [source] Evaluation of early stimulation programs for enhancing brain developmentACTA PAEDIATRICA, Issue 7 2008Christine Bonnier Abstract The term ,early intervention' designates educational and neuroprotection strategies aimed at enhancing brain development. Early educational strategies seek to take advantage of cerebral plasticity. Neuroprotection, a term initially used to characterize substances capable of preventing cell death, now encompasses all interventions that promote normal development and prevent disabilities, including organisational, therapeutic and environment-modifying measures, such as early stimulation programs. Early stimulation programs were first devised in the United States for vulnerable children in low-income families; positive effects were recorded regarding school failure rates and social problems. Programs have also been implemented in several countries for premature infants and low-birth-weight infants, who are at high risk for neurodevelopmental abnormalities. The programs target the child, the parents or both. The best evaluated programs are the NIDCAP (Newborn Individualized Developmental Care and Assessment Program) in Sweden for babies <1500 g in neonatal intensive care units and the longitudinal multisite program IHDP (Infant Health and Development Program) created in the United States for infants <37 weeks or <2500 g. Conclusion: Although the NIDCAP and the IHDP targeted different populations, they produced similar effects in several regards: efficacy was greatest with programs involving both the parents and the child; long-term stimulation improved cognitive outcomes and child,parent interactions; cognition showed greater improvements than motor skills and larger benefits were obtained in families that combined several risk factors including low education attainment by the mothers. [source] | ||||||||||