Journal of molecular neuroscience : MN
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Multicenter Study
Validity of the Mindstreams computerized cognitive battery for mild cognitive impairment.
The NeuroTrax Mindstreams computerized cognitive assessment system was designed for widespread clinical and research use in detecting mild cognitive impairment (MCI). However, the capability of Mindstreams tests to discriminate the elderly with MCI from those who are cognitively healthy has yet to be evaluated. Moreover, the comparability between these tests and traditional neuropsychological tests in detecting MCI has not been examined. ⋯ Measures of memory, executive function, visual spatial skills, and verbal fluency discriminated best, and discriminability was at least comparable to that of traditional neuropsychological tests in these domains. Mindstreams tests are effective in detecting MCI, providing a comprehensive profile of cognitive function. Further, the enhanced precision and ease of use of these computerized tests make the NeuroTrax system a valuable clinical tool in the identification of elders at high risk for dementia.
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Chronic treatments with antidepressants active on major depressive disorders influence pathways involved in cell survival and plasticity. As astrocytes seem to play a key role in the protection of brain cells, we investigated in these cells the rapid effects of the antidepressant fluoxetine (Prozac) on signaling cascades and gene induction, which probably play a role in neuroprotection. We show here that fluoxetine alone activates the extracellular signal-regulated-protein kinase (Erk) and p38 mitogen-associated protein (MAP) kinase cascades. ⋯ Glial-derived nerve factor (GDNF) induction by fluoxetine is prevented by U0126, suggesting that Erk is implicated. Brain-derived nerve factor (BDNF) induction seems mediated by other signaling pathways. In conclusion, we show that fluoxetine alone rapidly activates mitogen activated protein (MAP) kinase cascades in rat astrocytes and that genes involved in neuroprotection are induced in a few hours in a MAP kinase-dependent or -independent manner.
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One of the prominent pathological features of Parkinson's disease (PD) is the abnormal accumulation of iron in the substantia nigra pars compacta (SNpc), in the reactive microglia, and in association with neuromelanin, within the melanin-containing dopamine (DA) neurons. Lewy body, the morphological hallmark of PD, is composed of lipids, redox-active iron, and aggregated alpha-synuclein, concentrating in its peripheral halo and ubiquitinated, hyperphosphorylated, neurofilament proteins. The capacity of free iron to enhance and promote the generation of toxic reactive oxygen radicals has been discussed numerous times. ⋯ The accumulation of iron in MPTP-induced neurodegeneration has been linked to nitric oxide-dependent mechanism, resulting in degradation of prominent iron regulatory proteins by ubiquitination. Radical scavengers such as R-apomorphine and green tea catechin polyphenol (-)-epigallocatechin-3-gallate, as well as the recently developed brain-permeable VK-28 series derivative iron chelators, which are neuroprotective against these neurotoxins in mice and rats, prevent the accumulation of iron and alpha-synuclein in SNpc. This study supports the notion that a combination of iron chelation and antioxidant therapy, as emphasized on several occasions, might be a significant approach to neuroprotection in PD and other neurodegenerative diseases.
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Neurostimulation for refractory angina pectoris is often advocated for its clinical efficacy. However, the recruited pathways to induce electroanalgesia are partially unknown. Therefore, we sought to study the effect of neurostimulation on experimentally induced cardiac nociception, using capsaicin as nociception-induced substance. ⋯ In the paraventricular thalamus, periaqueductal gray, and central amygdala, no significant differences were noticed among the first three groups, and the c-fos concentration in these three groups was significantly higher than in group ShamVeh. It is concluded that neurostimulation does not influence capsaicin-induced cardiac nociceptive pain pulses to the central nervous system. Furthermore, capsaicin-induced cardiac pain and neurostimulation may utilize two different pathways.
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Malignant hyperthermia (MH) is a potentially lethal pharmacogenetic predisposition associated with a susceptibility to volatile anesthetics and depolarizing muscle relaxants that lead to a fulminant anesthetic crisis with hyperthermia, skeletal muscle rigidity, respiratory and metabolic acidosis, and muscle rhabdomyolysis. Malignant hyperthermia crises are caused by an abnormal regulation of the calcium release mechanism, which reflects the consequences of disturbed skeletal muscle calcium homeostasis. We screened 64 individuals of 27 unrelated families for the most frequently described mutations associated with MH in the genes RYR1 and CACNL1A3. ⋯ To elucidate which other mechanism could lead to susceptibility in the members of this family, we tested it for further MH susceptibility loci. The same haplotype was shown to segregate with the individuals carrying the Arg614Cys mutation in chromosome 19; however, the other susceptible and equivocal individuals do not share this haplotype. Markers for the susceptible locus in chromosome regions 17q, 7q, 3q, and 5p did not segregate with the IVCT phenotype in the susceptible individuals, suggesting that the positivity of the IVCT could be attributable to other ambient factors.