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Sant'Ambrogio di Torino, Italy

Hickey C.,VU University Amsterdam | Hickey C.,University of Trento | Chelazzi L.,University of Verona | Chelazzi L.,Italian Institute of Neuroscience | Theeuwes J.,VU University Amsterdam
PLoS ONE | Year: 2014

Existing visual search research has demonstrated that the receipt of reward will be beneficial for subsequent perceptual and attentional processing of features that have characterized targets, but detrimental for processing of features that have characterized irrelevant distractors. Here we report a similar effect of reward on location. Observers completed a visual search task in which they selected a target, ignored a salient distractor, and received random-magnitude reward for correct performance. Results show that when target selection garnered rewarding outcome attention is subsequently a.) primed to return to the target location, and b.) biased away from the location that was occupied by the salient, task-irrelevant distractor. These results suggest that in addition to priming features, reward acts to guide visual search by priming contextual locations of visual stimuli. © 2014 Hickey et al. Source


Uccelli A.,University of Genoa | Uccelli A.,Advanced Biotechnology Center | Milanese M.,University of Genoa | Principato M.C.,University of Genoa | And 11 more authors.
Molecular Medicine | Year: 2012

Despite some advances in the understanding of amyotrophic lateral sclerosis (ALS) pathogenesis, significant achievements in treating this disease are still lacking. Mesenchymal stromal (stem) cells (MSCs) have been shown to be effective in several models of neurological disease. To determine the effects of the intravenous injection of MSCs in an ALS mouse model during the symptomatic stage of disease, MSCs (1 × 106) were intravenously injected in mice expressing human superoxide dismutase 1 (SOD1) carrying the G93A mutation (SOD1/G93A) presenting with experimental ALS. Survival, motor abilities, histology, oxidative stress markers and [3H]D-aspartate release in the spinal cord were investigated. MSC injection in SOD1/G93A mice improved survival and motor functions compared with saline-injected controls. Injected MSCs scantly home to the central nervous system and poorly engraft. We observed a reduced accumulation of ubiquitin agglomerates and of activated astrocytes and microglia in the spinal cord of MSC-treated SOD1/G93A mice, with no changes in the number of choline acetyltransferase- and glutamate transporter type 1-positive cells. MSC administration turned around the upregulation of metallothionein mRNA expression and of the activity of the antioxidant enzyme glutathione S-transferase, both associated with disease progression. Last, we observed that MSCs reverted both spontaneous and stimulus-evoked neuronal release of [3H]D-aspartate, a marker of endogenous glutamate, which is upregulated in SOD1/G93A mice. These findings suggest that intravenous administration of MSCs significantly improves the clinical outcome and pathological scores of mutant SOD1/G93A mice, thus providing the rationale for their exploitation for the treatment of ALS. Source


Condliffe S.B.,National Research Council Italy | Corradini I.,National Research Council Italy | Pozzi D.,National Research Council Italy | Pozzi D.,Italian Institute of Neuroscience | And 2 more authors.
Journal of Biological Chemistry | Year: 2010

In addition to its primary role as a fundamental component of the SNARE complex, SNAP-25 also modulates voltage-gated calcium channels (VGCCs) in various overexpression systems. Although these studies suggest a potential negative regulatory role of SNAP-25 on VGCC activity, the effects of endogenous SNAP-25 on native VGCC function in neurons are unclear. In the present study, we investigated the VGCC properties of cultured glutamatergic and GABAergic rat hippocampal neurons. Glutamatergic currents were dominated by P/Q-type channels, whereas GABAergic cells had a dominant L-type component. Also, glutamatergic VGCC current densities were significantly lower with enhanced inactivation rates and shifts in the voltage dependence of activation and inactivation curves compared with GABAergic cells. Silencing endogenous SNAP-25 in glutamatergic neurons did not alter P/Q-type channel expression or localization but led to increased VGCC current density without changes in the VGCC subtype proportions. Isolation of the P/Q-type component indicated that increased current in the absence of SNAP-25 was correlated with a large depolarizing shift in the voltage dependence of inactivation. Overexpressing SNAP-25 in GABAergic neurons reduced current density without affecting the VGCC subtype proportion. Accordingly, VGCC current densities in glutamatergic neurons from Snap-25+/- mice were significantly elevated compared with wild type glutamatergic neurons. Overall, this study demonstrates that endogenous SNAP-25 negatively regulates native VGCCs in glutamatergic neurons which could have important implications for neurological diseases associated with altered SNAP-25 expression. © 2010 by The American Society for Biochemistry and Molecular Biology, Inc. Source


Caselli L.,University of Verona | Caselli L.,University of Parma | Chelazzi L.,University of Verona | Chelazzi L.,Italian Institute of Neuroscience
PLoS ONE | Year: 2011

The ability to swiftly and smoothly switch from one task set to another is central to intelligent behavior, because it allows an organism to flexibly adapt to ever changing environmental conditions and internal needs. For this reason, researchers interested in executive control processes have often relied on task-switching paradigms as powerful tools to uncover the underlying cognitive and brain architecture. In order to gather fundamental information at the single-cell level, it would be greatly helpful to demonstrate that non-human primates, especially the macaque monkey, share with us similar behavioral manifestations of task-switching and therefore, in all likelihood, similar underlying brain mechanisms. Unfortunately, prior attempts have provided negative results (e.g., Stoet & Snyder, 2003b), in that it was reported that macaques do not show the typical signature of task-switching operations at the behavioral level, represented by switch costs. If confirmed, this would indicate that the macaque cannot be used as a model approach to explore human executive control mechanisms by means of task-switching paradigms. We have therefore decided to re-explore this issue, by conducting a comparative experiment on a group of human participants and two macaque monkeys, whereby we measured and compared performance costs linked to task switching and resistance to interference across the two species. Contrary to what previously reported, we found that both species display robust task switching costs, thus supporting the claim that macaque monkeys provide an exquisitely suitable model to study the brain mechanisms responsible for maintaining and switching task sets. © 2011 Caselli, Chelazzi. Source

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