206 research outputs found

    One Week of Motor Adaptation Induces Structural Changes in Primary Motor Cortex That Predict Long-Term Memory One Year Later

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    The neural bases of motor adaptation have been extensively explored in human and non-human primates. A network including the cerebellum, primary motor and the posterior parietal cortex appears to be crucial for this type of learning. Yet, to date, it is unclear whether these regions contribute directly or indirectly to the formation of motor memories. Here we trained subjects on a complex visuomotor rotation associated with long-term memory (in the order of months) to identify potential sites of structural plasticity induced by adaptation. One week of training led to i) an increment in local gray-matter concentration over the hand area of the contralateral primary motor cortex and ii) an increase in fractional anisotropy in an area underneath this region that correlated with the speed of learning. Moreover, the change in gray matter concentration measured immediately after training predicted improvements in the speed of learning during re-adaptation one year later. Our study suggests that motor adaptation induces structural plasticity in primary motor circuits. In addition, it provides the first piece of evidence indicating that early structural changes induced by motor learning may impact on behavior up to one year after training.Fil: Landi, Sofía Mariana. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas. Cátedra de Fisiologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Baguear, Miguel Federico. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas. Cátedra de Fisiologia; ArgentinaFil: Della Maggiore, Valeria Monica. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas. Cátedra de Fisiologia; Argentin

    Assembling and auditing a comprehensive DNA barcode reference library for European marine fishes

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    A large-scale comprehensive reference library of DNA barcodes for European marine fishes was assembled, allowing the evaluation of taxonomic uncertainties and species genetic diversity that were otherwise hidden in geographically restricted studies. A total of 4118 DNA barcodes were assigned to 358 species generating 366 Barcode Index Numbers (BIN). Initial examination revealed as much as 141 BIN discordances (more than one species in each BIN). After implementing an auditing and five-grade (A-E) annotation protocol, the number of discordant species BINs was reduced to 44 (13% grade E), while concordant species BINs amounted to 271 (78% grades A and B) and 14 other had insufficient data (grade D). Fifteen species displayed comparatively high intraspecific divergences ranging from 2·6 to 18·5% (grade C), which is biologically paramount information to be considered in fish species monitoring and stock assessment. On balance, this compilation contributed to the detection of 59 European fish species probably in need of taxonomic clarification or re-evaluation. The generalized implementation of an auditing and annotation protocol for reference libraries of DNA barcodes is recommended.info:eu-repo/semantics/publishedVersio

    Spatiotemporal genetic variation of atlantic bluefin tunas from sardinian and mediterranean tuna traps

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    Tuna traps of the Sardinian and Mediterranean have provided from long to short term series of data and samples of bluefin tuna (BFT) populations inhabiting the Mediterranean. By analyzing genetic variation in BFT trap samples, we have shown that more than one BFT population have been entered and spread in the Mediterranean across the last century and that over short period, the interannual composition of BFT trap catches are genetically constant

    Proteomics coupled with AhR-reporter gene bioassay for human and environmental safety assessment of sewage sludge and hydrochar

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    Today application of sewage sludge (SL) and hydrochar (HC) in agriculture is a common practice for soil conditioning and crop fertilization, however safety concerns for human and environmental health due to the presence of toxic compounds have recently been expressed. Our aim was to test the suitability of proteomics coupled with bioanalytical tools for unravelling mixture effects of these applications in human and environmental safety assessment. We conducted proteomic and bioinformatic analysis of cell cultures used in the DR-CALUX® bioassay to identify proteins differentially abundant after exposure to SL and the corresponding HC, rather than only using the Bioanalytical Toxicity Equivalents (BEQs) obtained by DR-CALUX®. DR-CALUX® cells exposed to SL or HC showed a differential pattern of protein abundance depending on the type of SL and HC extract. The modified proteins are involved in antioxidant pathways, unfolded protein response and DNA damage that have close correlations with the effects of dioxin on biological systems and with onset of cancer and neurological disorders. Other cell response evidence suggested enrichment of heavy metals in the extracts. The present combined approach represents an advance in the application of bioanalytical tools for safety assessment of complex mixtures such as SL and HC. It proved successful in screening proteins, the abundance of which is determined by SL and HC and by the biological activity of legacy toxic compounds, including organohalogens

    Updated checklist of marine fishes (Chordata: Craniata) from Portugal and the proposed extension of the Portuguese continental shelf

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    The study of the Portuguese marine ichthyofauna has a long historical tradition, rooted back in the 18th Century. Here we present an annotated checklist of the marine fishes from Portuguese waters, including the area encompassed by the proposed extension of the Portuguese continental shelf and the Economic Exclusive Zone (EEZ). The list is based on historical literature records and taxon occurrence data obtained from natural history collections, together with new revisions and occurrences. It comprises a total of 1191 species, distributed among 3 superclasses, 4 classes, 42 orders, 212 families and 617 genera. If considering only the EEZ and present territorial waters, this list represents an increase of 230 species (27.8%) and of 238 species (29.0%), when compared to the information available in FishBase (2012) and in the last checklist of marine and estuarine fishes of Portugal (1993), respectively. The order Perciformes shows the highest diversity, with 54 families, 162 genera and 299 species. Stomiidae (80 species), Myctophidae (71 species) and Macrouridae (37 species) are the richest families. From the listed species, 734 are present off mainland Portugal, 857 off the Azores and 766 off Madeira. Within the limits of the examined area, three species are reported for the first time in mainland Portugal and twenty-nine records are identified as doubtful. A total of 133 species have been recorded from the extended Portuguese continental shelf (2 off mainland Portugal, 117 off the Azores and 14 off Madeira), two of which are common to the Azores and Madeira extensions. Biogeographically, the Atlantic group is the most important (548 species – 46.01%), followed by the Lusitanian group (256 species – 21.49%), the African group (71 species – 5.96%), the Boreal group (34 species – 2.85%), the Mediterranean group (31 species – 2.60%), the Macaronesian group (21 species – 1.76%), the Atlantic/African group (19 species – 1.60%) and the Mediterranean/African and the Arctic groups, each with only 1 species (0.08%). Regarding the preferences for vertical habitat, the demersal fishes are the most important group (305 species – 25.61%), followed by the mesopelagic group (228 species – 19.14%), the bathypelagic group (164 species – 13.77%), the benthopelagic group (147 species – 12.34%), the bathydemersal group (115 species – 9.66%), the reef-associated group (88 species – 7.39%), the pelagic group (74 species – 6.21%), the epipelagic group (58 species – 4.87%) and 1 species (0.08%) of the benthic group. The oceanic habitat is the best represented group comprising 446 species (37.45%), followed by the shelf group (199 species – 16.71%), the slope group (164 species – 13.77%), the inner shelf group (89 species – 7.47%), the coastal group (70 species – 5.88%), the outer shelf group (29 species – 2.43%) and the oceanic/shelf group (7 species – 0.59%)

    Quaternary geographical sibling speciation and population structuring in the Eastern Atlantic skates (suborder Rajoidea) Raja clavata and R. straeleni

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    To access the final version, follow the next link. http://www.springerlink.com/content/t1809472211lk67q/Aim Geographical (allopatric) speciation is a dynamic process whose footprints in the living world are a continuum of stages of increasing divergence. Geographical speciation can also contribute to the evolution of marine taxa. This study looked for two of these evolutionary stages (i.e. structured populations and sibling species) in the diversification patterns of two Atlantic skates (Raja, suborder Rajoidea) which exhibited high morphological and ecological conservativism(undefined

    The polymorphism rs2480258 within CYP2E1 is associated with different rates of acrylamide metabolism in vivo in humans

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    In a recent study, we demonstrated that the variant allele of rs2480258 within intron VIII of CYP2E1 is associated with reduced levels of mRNA, protein, and enzyme activity. CYP2E1 is the most important enzyme in the metabolism of acrylamide (AA) by operating its oxidation into glycidamide (GA). AA occurs in food, is neurotoxic and classified as a probable human carcinogen. The goal of the present study was to further assess the role of rs2480258 by measuring the rate of AA > GA biotransformation in vivo. In blood samples from a cohort of 120 volunteers, the internal doses of AA and GA were assessed by AA and GA adducts to hemoglobin (Hb) measured by mass spectrometry. The rate of biotransformation was assessed by calculating the GA-Hb/AA-Hb ratio. To maximize the statistical power, 60 TT was compared to 60 CC-homozygotes and the results showed that TT homozygotes had a statistically significant reduced rate of biotransformation. Present results reinforced the notion that T-allele of rs2480258 is a marker of low functional activity of CYP2E1. Moreover, we studied the role of polymorphisms (SNPs) within glutathione-S-transferases (GSTs) enzymes and epoxide hydrolase (EPHX), verifying previous findings that SNPs within GSTs and EPHX influence the metabolism rate

    Association between CYP2E1 polymorphisms and risk of differentiated thyroid carcinoma

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    Differentiated thyroid carcinoma (DTC) results from complex interactions between genetic and environmental factors. Known etiological factors include exposure to ionizing radiations, previous thyroid diseases, and hormone factors. It has been speculated that dietary acrylamide (AA) formed in diverse foods following the Maillard's reaction could be a contributing factor for DTC in humans. Upon absorption, AA is biotransformed mainly by cytochrome P450 2E1 (CYP2E1) to glycidamide (GA). Considering that polymorphisms within CYP2E1 were found associated with endogenous levels of AA-Valine and GA-Valine hemoglobin adducts in humans, we raised the hypothesis that specific CYP2E1 genotypes could be associated with the risk of DTC. Analysis of four haplotype tagging SNPs (ht-SNPs) within the locus in a discovery case-control study (N = 350/350) indicated an association between rs2480258 and DTC risk. This ht-SNP resides within a linkage disequilibrium block spanning intron VIII and the 3'-untranslated region. Extended analysis in a large replication set (2429 controls and 767 cases) confirmed the association, with odds ratios for GA and AA genotypes of 1.24 (95 % confidence interval (CI) 1.03-1.48) and 1.56 (95 % CI, 1.06-2.30), respectively. Functionally, the minor allele was associated with low levels of CYP2E1 mRNA and protein expression as well as lower enzymatic activity in a series of 149 human liver samples. Our data support the hypothesis that inter-individual differences in CYP2E1 activity could modulate the risk of developing DTC suggesting that the exposure to specific xenobiotics, such as AA, could play a role in this process
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