Neuroscience
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The suggestion of an anatomical and functional relationship between the basal ganglia and cerebellum is recent. Traditionally, these structures were considered as neuronal circuits working separately to organize and control goal-directed movements and cognitive functions. However, several studies in rodents and primates have described an anatomical interaction between cortico-basal and cortico-cerebellar networks. ⋯ After 14days of haloperidol treatment, the vermis and cerebellar hemispheres showed an opposite regulation of cFOS expression. Chronic dopaminergic antagonism lessened cFOS expression in the vermis but up-regulated such expression in the cerebellar hemisphere. Overall, the present data indicate a very close functional relationship between the basal ganglia and the cerebellum and they may allow a better understanding of disorders in which there are dopamine alterations.
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Homer protein, a member of the post-synaptic density protein family, plays an important role in the neuronal synaptic activity and is extensively involved in neurological disorders. The present study investigates the role of Homer1b/c in modulating neuronal survival by using an in vitro traumatic neuronal injury model, which was achieved by using a punch device that consisted of 28 stainless steel blades joined together and produced 28 parallel cuts. ⋯ Therefore, Homer1b/c not only modulated the mGluR1a-inositol 1,4,5-triphosphate receptors-Ca(2+) signal transduction pathway, but also regulated the expression of mGluR1a in mechanical neuronal injury. These findings indicate that the suppression of Homer1b/c expression potentially protects neurons from glutamate excitotoxicity after injury and might be an effective intervention target in traumatic brain injury.
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Impaired balance may limit mobility and daily activities, and plays a key role in the elderly falling. Maintaining balance requires a concerted action of the sensory, nervous and motor systems, whereby cause and effect mutually affect each other within a closed loop. Aforementioned systems and their connecting pathways are prone to chronological age and disease-related deterioration. ⋯ This paper outlines the multiple deteriorations of the underlying systems that may be involved in standing balance, which have to be detected early to prevent impaired standing balance. An overview of clinically used balance tests shows that early detection of impaired standing balance and identification of causal mechanisms is difficult with current tests, thereby hindering the development of well-timed and target-oriented interventions as described next. Finally, a new approach to assess standing balance and to detect the underlying deteriorations is proposed.
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Although extensively investigated in socio-cognitive neuroscience, empathy is difficult to study. The first difficulty originates in its multifaceted nature. According to the multidimensional model, empathy combines emotional, automatic (simulation), cognitive (mentalizing) and regulatory (executive functions) processes. ⋯ However, at 333-424ms, empathy triggered greater co-activations in the right IFG and dorsolateral prefrontal cortex (dlPFC) (executive functions). Linking together our present and prior (Thirioux et al., 2010) findings from the same dataset, we suggest that this greater recruitment of the right dlPFC monitors the shift from egocentered and first-person-like mechanisms in the MNS to heterocentered and second-person-like mechanisms in the left temporo-parietal junction within the MENT, i.e., reflecting the onset of perspective-change processes in the neural time course of empathy. Contrasting with sympathy, this recruitment of the executive functions could modulate the output end of the mirroring processing in the premotor and sensorimotor cortices.
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Dimebon (dimebolin or latrepirdine), originally developed as an anti-histaminic drug, has been investigated and proposed as a cognitive enhancer for treating neurodegenerative disorders such as Alzheimer's and Huntington's diseases, and more recently schizophrenia. This study was conducted to evaluate the potential neuroprotective effect of dimebon during brain ischemia using rat hippocampal slices subjected to oxygen and glucose deprivation followed by a reoxygenation period (OGD/Reox) or glutamate excitotoxicity. Dimebon, incubated during the OGD/Reox period, caused a concentration -dependent protective effect of hippocampal slices; maximum protection (85%) was achieved at 30μM. ⋯ In the glutamate-induced excitotoxicity model, dimebon also afforded a concentration-dependent protective effect that was significantly higher than that obtained with memantine, a non-competitive N-methyl-d-aspartate (NMDA) antagonist. When changes in the intracellular calcium concentration were evaluated in Fluo-4-loaded rat hippocampal neurons, glutamate-induced calcium transients were reduced by 20% with dimebon. These results suggest that dimebon could counteract different pathophysiological processes during ischemic brain damage and, could therefore, be considered as a novel therapeutic strategy for cerebral ischemia-reoxygenation injury.