Pawedness trait test (PaTRaT) : a new paradigm to evaluate paw preference and dexterity in rats

Pawedness Trait Test (PaTRaT)-A New Paradigm to Evaluate Paw Preference and Dexterity in RatsIn rodents, dexterity is commonly analyzed in preference paradigms in which animals are given the chance to use either the left or the right front paws to manipulate food. However, paw preference and dexterity at population and individual levels are controversial as results are incongruent across paradigms. We have therefore developed a semi-quantitative method-the pawdeness trait test (PaTRaT)-to evaluate paw preference degree in rats. The PaTRaT consists in a classification system, ranging from +4 to 4 where increasingly positive and negative values reflect the bias for left or right paw use, respectively. Sprague-Dawley male rats were confined into a metal rectangular mesh cylinder, from which they can see, smell and reach sugared rewards with their paws. Due to its size, the reward could only cross the mesh if aligned with its diagonal, imposing additional coordination. Animals were allowed to retrieve 10 rewards per session in a total of four sessions while their behavior was recorded. PaTRaT was repeated 4 and 8 weeks after the first evaluation. To exclude potential bias, rats were also tested for paw fine movement and general locomotion in other behavioral paradigms as well as impulsivity (variable delay-to-signal, VDS), memory and cognitive flexibility (water maze). At the population level 54% of the animals presented a rightward bias. Individually, all animals presented marked side-preferences, >2 and <-2 for left-and right-sided bias, respectively, and this preference was stable across the three evaluations. Inter-rater consistency was very high between two experienced raters and substantial when two additional inexperienced raters were included. Left-and right-biased animals presented no differences in the ability to perform fine movements with any of the forelimbs (staircase) and general locomotor performance. Additionally, these groups performed similarly in executive function and memory tasks. In conclusion, PaTRaT is able to reliably classify rats' pawedness direction and degree.This work has been funded by the European Regional Development Fund (FEDER), through the Competitiveness Factors Operational Programme (COMPETE) and the Northern Portugal Regional Operational Programme (NORTE 2020) under the Portugal 2020 Partnership Agreement (project NORTE-01-0145-FEDER-000023). It was also funded by National funds, through the Foundation for Science and Technology (Fundacao para a Ciencia e a Tecnologia, FCT), under the scope of the projects POCI-01-0145-FEDER-007038 and PTDC/NEU-SCC/5301/2014. Researchers were supported by FCT grant numbers SFRH/BD/109111/2015 (AMC), SFRH/BD/52291/2013 (ME via Inter-University Doctoral Programme in Ageing and Chronic Disease, PhDOC), PD/BD/114120/2015 (SPN via PhDOC), SFRH/BD/89936/2012 (SB), PD/BD/114117/2015 (MRG via PhDOC) and SFRH/BPD/80118/2011 (HL-A).info:eu-repo/semantics/publishedVersio

Evidence of Compromised Blood-Spinal Cord Barrier in Early and Late Symptomatic SOD1 Mice Modeling ALS

Background: The blood-brain barrier (BBB), blood-spinal cord barrier (BSCB), and blood-cerebrospinal fluid barrier (BCSFB) control cerebral/spinal cord homeostasis by selective transport of molecules and cells from the systemic compartment. In the spinal cord and brain of both ALS patients and animal models, infiltration of T-cell lymphocytes, monocyte-derived macrophages and dendritic cells, and IgG deposits have been observed that may have a critical role in motor neuron damage. Additionally, increased levels of albumin and IgG have been found in the cerebrospinal fluid in ALS patients. These findings suggest altered barrier permeability in ALS. Recently, we showed disruption of the BBB and BSCB in areas of motor neuron degeneration in the brain and spinal cord in G93A SOD1 mice modeling ALS at both early and late stages of disease using electron microscopy. Examination of capillary ultrastructure revealed endothelial cell degeneration, which, along with astrocyte alteration, compromised the BBB and BSCB. However, the effect of these alterations upon barrier function in ALS is still unclear. The aim of this study was to determine the functional competence of the BSCB in G93A mice at different stages of disease. Methodology/Principal Findings: Evans Blue (EB) dye was intravenously injected into ALS mice at early or late stage disease. Vascular leakage and the condition of basement membranes, endothelial cells, and astrocytes were investigated in cervical and lumbar spinal cords using immunohistochemistry. Results showed EB leakage in spinal cord microvessels from all G93A mice, indicating dysfunction in endothelia and basement membranes and confirming our previous ultrastructural findings on BSCB disruption. Additionally, downregulation of Glut-1 and CD146 expressions in the endothelial cells of the BSCB were found which may relate to vascular leakage. Conclusions/Significance: Results suggest that the BSCB is compromised in areas of motor neuron degeneration in ALS mice at both early and late stages of the disease

Protection of axotomized ganglion cells by salicylic acid

Neuronal survival is influenced by the redox environment, and it has been shown that antioxidants protect developing neurons from the effects of axotomy. Here, we show that the intraocular injection of salicylic acid (SA) reduces the number of dying axotomized ganglion cells in the chick embryo. The antioxidant properties of SA are probably responsible for its protective effects, whose U-shaped dose-dependency matches that of several other antioxidants. We conclude that SA protects axotomized neurons by maintaining the redox status near an optimal set-point

Brain neocortex immunomodulation in rats

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ÉTATS DE HAUT SPIN DE 154Er

Les états de haut moment angulaire du noyau 154Er ont été peuplés par les réactions 148Sm (12C, 6n) et 147Sm(12C, 5n) auprès du cyclotron de l'I.S.N. de Grenoble. Après étude des fonctions d'excitation entre 65 et 110MeV, les spectres de coïncidences γ-γ rapides et retardés par rapport au faisceau ainsi que les distributions angulaires (90°, 110°, 130° et 150°) et les périodes des niveaux (dans la gamme 10-100 ns) ont été mesurés à des énergies de 94 MeV et 110 MeV

ÉTATS DE HAUT SPIN DE 154Er

Les états de haut moment angulaire du noyau 154Er ont été peuplés par les réactions 148Sm (12C, 6n) et 147Sm(12C, 5n) auprès du cyclotron de l'I.S.N. de Grenoble. Après étude des fonctions d'excitation entre 65 et 110MeV, les spectres de coïncidences γ-γ rapides et retardés par rapport au faisceau ainsi que les distributions angulaires (90°, 110°, 130° et 150°) et les périodes des niveaux (dans la gamme 10-100 ns) ont été mesurés à des énergies de 94 MeV et 110 MeV

The \chem{^{130}Nd\to{}^{130}Pr\to{}^{130}Ce} decay chain revisited

An investigation of low-lying energy levels of $^{130}$Pr and $^{130}$Ce has been made via $\beta$-decay. The radioactive parent nuclei were produced via $^{94,96}$Mo + $^{40}$Ca reactions at 6.8 MeV/nucleon and transported by a He-jet system. Gamma-$\gamma$-t, $\gamma$-X-t, $\gamma$-e$^-$-t coincidence measurements were performed. Internal conversion coefficients have been measured with a magnetic spectrometer. The new $\beta$-decay half-life of $^{130}$Nd has been determined to be 21(3) s. A partial level scheme of $^{130}$Pr at low-spin has been constructed. The $\beta$-decay of $^{130}$Pr to $^{130}$Ce suggests the existence of three $\beta$-instable isomeric states in $^{130}$Pr, while only one half-life $T_{1/2} = 40(4)$ s has been measured. Based on the present work and low-lying excited states in neighbouring odd-mass nuclei, the spins and parities of isomeric states in $^{130}$Pr are proposed to be 2$^+$, (4,5)$^+$ and (7,8$^\mp$). The ground state in $^{130}$Pr is still undetermined