Trends in neurosciences
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Trends in neurosciences · Oct 2004
ReviewThe aging brain: morphomolecular senescence of cortical circuits.
The human brain is uniquely powerful with respect to cognitive abilities, yet the hippocampal and neocortical circuits that mediate such complex functions are highly vulnerable to aging. Their selective vulnerability is profoundly manifested in Alzheimer's disease (AD), where degeneration of select neurons leads to a near complete loss of cognitive abilities. Most of us will avoid AD as we age. ⋯ Animal studies suggest that both AD and age-associated cognitive impairment reflect vulnerability of the same circuits. However, neuron death predominates in the former, whereas the latter is probably mediated by synaptic alterations in otherwise intact circuits. Fortunately, such age-related synaptic alterations could be reversible, as suggested by recent studies of hormone replacement.
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Trends in neurosciences · Nov 2003
ReviewNeuromelanin of the substantia nigra: a neuronal black hole with protective and toxic characteristics.
Neuromelanin accumulates in dopaminergic neurons during normal aging, and in Parkinson's disease, neurons with this pigment are those that selectively degenerate. Intraneuronal neuromelanin could play a protective role during its synthesis by preventing the toxic accumulation of cytosolic catechol derivatives and, in addition, by its ability to scavenge reactive metals, pesticides and other toxins to form stable adducts. However, dying neurons in Parkinson's disease that release neuromelanin might induce a vicious cycle of chronic neuroinflammation and neuronal loss.
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Trends in neurosciences · Apr 2003
ReviewThe Nogo-66 receptor: focusing myelin inhibition of axon regeneration.
CNS myelin inhibits axonal outgrowth in vitro and is one of several obstacles to functional recovery following spinal cord injury. Central to our current understanding of myelin-mediated inhibition are the membrane protein Nogo and the Nogo-66 receptor (NgR). ⋯ Additional studies have identified a potential coreceptor for NgR as p75(NTR), and a second-messenger pathway involving RhoA that inhibits neurite elongation. Although these findings expand our understanding of the molecular determinants of adult CNS axonal regrowth, the physiological roles of myelin-associated inhibitors in the intact adult CNS remain ill-defined.
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Neuroscientists across Europe have been busy finding or consolidating partnerships, and sharpening their e-pencils, as they prepare for the next tranche of research and technology development (RTD) funding to be coordinated by the European Union. Entitled the Sixth Framework Programme, this 16 billion Euro programme is the most ambitious that the European Commission has ever mounted. It covers a broad range of RTD activities, from the very small (nanotechnology and nanosciences) to the very grand (sustainable development, global change and ecosystems). ⋯ This includes sub-sections entitled "Studying the brain and combating diseases of the nervous system" and "Studying development and ageing processes". The focus is likely to be on exploiting molecular genetics with respect to neuroscience. Our aim in this short article is to outline some of the novel features of this ambitious program and to touch on certain issues that have been raised about it.
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Trends in neurosciences · Oct 2002
Exploring brain connectivity: a new frontier in systems neuroscience. Functional Brain Connectivity, 4-6 April 2002, Dusseldorf, Germany.
Functional Brain Connectivity, held on 4-6 April 2002, Dusseldorf, Germany.