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

"Acute pseudo-pericardial tamponade": the compression of the thoracal inferior vena cava – a case report

We describe a case of 68-year-old woman which was admitted to our hospital for mitral valve replacement (MVR), in whom acute compresion of the vena cava inferior developed after repair of lacerated atrio-caval junction with hemostatic tissue sealant, biologic glue (BioGlue, Cryolife, ınc, Kennesaw, Ga). Removal of the BioGlue relieved the unexpected problem

Sexual dimorphism in relations of blood growth-hormone levels to body and brain weights in newborn rats

PubMedID: 17987475The growth promoting effects of growth hormone (GH) are well-known. However, the studies in this respect did not consider the sexual dimorphism. The adverse - growth limiting - GH effects were also reported in human newborns (see Tan, 1992, 1995; Tan et al., 1998). A similar study was replicated in the newborn rat pups in the present work. The serum GH level, body weight, body height, right- and left-brain weights were measured just after birth in rat pups. The relations of the serum GH levels to the bodily measurements were found to be sexually dimorphic. Namely, there were no significant correlations between the serum GH levels and the body size (weight and height) in males, whereas there were inverse relations between these parameters in females. The GH level negatively linearly related to the right-, left-, and right- minus left-brain weights in females, whereas only the right-brain weight positively linearly correlated with the serum GH level, the right- minus left-brain weight being also positively linearly correlated with the serum GH level in males. The results suggested that the sexual dimorphism should be taken into consideration in studies concerning the global GH effects. The relation of the serum GH level to the right-left brain asymmetry, also sexually dimorphic, suggests a role of GH in cerebral lateralization. Copyright © 2007 Informa Healthcare USA, Inc

Dynamics of manual skill: A computerized analysis of single peg movements and stochastic resonance hypothesis of cerebral laterality

PubMedID: 18300013Hand skill was analyzed using a computerized peg moving task. The durations of single hand movements (PMTs) were accurately measured in right-hand (RH) and left-hand (LH) writers. One trial consisted of 10 movements of the right hand and 10 movements of the left hand. Each participant performed five trials. Women showed significantly higher percentage than men in right-handedness; men showed higher percentage than women in left-handedness. This sex difference completely disappeared after taking the same height range in participants. The mean RH- and LH-PMTs decreased in 5 successive trials, even within a single trial during 10 successive hand movements, indicating a learning effect of repeated hand movements. The LH- minus RH-PMTs exhibited fluctuations within a single trial between positive (faster right hand) and negative (faster left hand) values. LH-RH PMTs were significantly greater than zero, in favor of right hand, in RH-writers, but not significantly different from zero in LH-writers, exhibiting a true fluctuating asymmetry. Participants with no familial sinistrality (FS-) were preponderantly right-handed (ca. 90%), those with left-handed mother and right-handed father (FS+1) showed stochastic distribution of hand preference (50:50). Participants with right-handed mother and left-hander father (FS+2) were not different from FS- individuals. LH-RH PMT was significantly greater than zero in FS- participants, almost equal to zero in FS+1 participants, and greater than zero in FS+2 participants exhibiting greater asymmetry than that in FS- participants. These results suggest a genetic inheritance of direction and degree of handedness, being a a X-linked trait originating from mother's genotype. It was suggested that fluctuating asymmetries may reflect interactions between stochastic resonance phenomena within right and left brains. This property of brain may genetically transmitted from mother's X chromosome; a net effect of stochastic interactions between hemispheres may result in right- or left-handedness, a predominantly unidirectional coupling creating right-handedness, in favor of left brain, and a stochastic bi-directional coupling between hemispheres would be a main trait of left-handers. This new "stochastic resonance hypothesis of cerebral laterality" concerns with stochastic fluctuations in hand-skill asymmetry and inter-hemispheric coupling through corpus callosum, and seems to be important for new developments in handedness research. Copyright © 2008 Informa Healthcare USA, Inc

Production of biosilica based bioactive glass-alginate composite putty as bone support material, and evaluation of in vitro properties; bioactivity and cytotoxicity behavior

In this study, we prepared biosilica and commercial silica based bioactive glasses with melt-quenching method, and utilized them as the solid phase of composite putties produced using sodium alginate polymer as the liquid phase. Biosilica based and commercial silica based bioactive glass containing composite putties were investigated and compared in terms of rheological features, bioactivity behavior and effect on cell viability. Rheological studies revealed that produced composite putties using both biosilica based and commercial silica based bioactive glasses were both shear thinning (pseudo-plastic) fluids with different consistency coefficient values. Biosilica based and commercial silica based composite putty materials showed differences between each other in terms of bioactivity and did not show any adverse effect on cell viability. Thus, the material features of meltquenched biosilica based bioactive glass/alginate formulations seem relevant for bone tissue engineering applications and biosilica may reduce production costs of these materials