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Biology subjects

Salvatori, D.

Publications and source records attributed to Salvatori, D..

3 recordsLinked to original sources

Rotating Letters in the Mind's Eye: Behavioral and electro-cortical associations with 3D Mental-Rotation Ability

Mental rotation in 3D is a key cognitive skill involving dynamic spatial transformations, for which pronounced individual differences have been documented. Here we ask whether individual differences in 3D abilities can be explained by analogous differences in 2D abilities. 3D mental-rotation was assessed by the Vandenberg & Kruse Mental Rotation Test (3D-MRT) and examined for association with performance and underlying electrocortical mechanisms during a 2D letter rotation task. Participants (N=40) first completed the MRT and then performed a computerized 2-D letter rotation task in which they had to identify whether letters were oriented in a standard or a mirrored direction (parity judgment) when rotated at 0{degrees}, 60{degrees}, 120{degrees}, and 180{degrees} while EEG was recorded. Reaction times (RTs) and error rates increased with angular disparity. The angular disparity effect on RT was smaller for mirrored letters. Low, relative to high, 3D-MRT scoring participants showed more pronounced accuracy declines at higher rotation angles. An EEG Event Related Potential (ERP) known as the Rotation-Related Negativity (RRN) became more pronounced with increasing angular disparity. High 3D-MRT scores were associated with a stronger RRN response at central-parietal sites. In addition, the ERP-P3b wave was more pronounced at central-parietal sites for low 3D-MRT scorers, independent of angular disparity. It is concluded that 3D rotational ability is positively associated with 2D mental rotation performance, and more strongly with enhanced recruitment of neural visual-spatial cortical representations than with enhanced recruitment of more general cognitive resources.

neuroscience↗

Gain of chromosome region 1q31.3 in human iPSCs confers growth advantage and alters contraction in derivative cardiomyocytes

hPSCs can acquire chromosomal aberrations such as copy number variations during prolonged maintenance in vitro, conferring growth advantages. However, the effect of these culture-acquired mutations on the phenotypes of the differentiated hPSCs is largely unstudied. Here, we identified mosaicism in a hPSC line in which some cells showed a gain of chromosome 1q31.3. We subcloned the wild-type and variant hPSCs and could maintain both as stable lines. While both variant and wildtype lines differentiated efficiently to cardiomyocytes (hPSC-CMs), molecular analysis revealed the variant hPSC-CMs had increased expression of TNNT2, a gene encoding one of the major sarcomere proteins mediating cardiomyocyte contractility and located within the gained chromosome 1q region. Moreover, the variant hPSC-CMs showed altered contraction kinetics. Together these results highlight the importance of careful monitoring of chromosome aberrations in hPSC lines as these could have confounding effects in various applications such as disease modelling and drug discovery.

cell biology↗

Trabeculations of the porcine and human cardiac ventricles are different in number but similar in total volume.

An intricate meshwork of trabeculations lines the luminal side of cardiac ventricles. Compaction, a developmental process, is thought to reduce trabeculations by adding them to the neighboring compact wall which is then enlarged. When pig, a plausible cardiac donor for xenotransplantation, is compared to human, the ventricular walls appear to have fewer trabeculations. We hypothesized the trabecular volume is proportionally smaller in pig than in human. Macroscopically, we observed in sixteen pig hearts that the ventricular walls harbor few but large trabeculations. Close inspection revealed a high number of tiny trabeculations, a few hundred, within the recesses of the large trabeculations. While tiny, these were still larger than embryonic trabeculations and even when considering their number, the total tally of trabeculations in pig was much fewer than in human. Volumetrics based on high-resolution MRI of additional six pig hearts compared to six human hearts, revealed the left ventricles were not significantly differently trabeculated (21.5 versus 22.8%, respectively), and the porcine right ventricles were only slightly less trabeculated (42.1 versus 49.3%, respectively). We then analyzed volumetrically ten pig embryonic hearts from gestational day 14 to 35. The trabecular and compact layer always grew, as did the intertrabecular recesses, in contrast to what compaction predicts. The proportions of the trabecular and compact layers changed substantially, nonetheless, due to differences in their growth rate rather than compaction. In conclusion, processes that affect the trabecular morphology do not necessarily affect the proportion of trabecular-to-compact myocardium and they are then distinct from compaction.

developmental biology↗