Alcohol-induced damage to the fimbria/fornix reduces hippocampal-prefrontal cortex connection during early abstinence

[EN] IntroductionAlcohol dependence is characterized by a gradual reduction in cognitive control and inflexibility to contingency changes. The neuroadaptations underlying this aberrant behavior are poorly understood. Using an animal model of alcohol use disorders (AUD) and complementing diffusion-weighted (dw)-MRI with quantitative immunohistochemistry and electrophysiological recordings, we provide causal evidence that chronic intermittent alcohol exposure affects the microstructural integrity of the fimbria/fornix, decreasing myelin basic protein content, and reducing the effective communication from the hippocampus (HC) to the prefrontal cortex (PFC). Using a simple quantitative neural network model, we show how disturbed HC-PFC communication may impede the extinction of maladaptive memories, decreasing flexibility. Finally, combining dw-MRI and psychometric data in AUD patients, we discovered an association between the magnitude of microstructural alteration in the fimbria/fornix and the reduction in cognitive flexibility. Overall, these findings highlight the vulnerability of the fimbria/fornix microstructure in AUD and its potential contribution to alcohol pathophysiology.Fimbria vulnerability to alcohol underlies hippocampal-prefrontal cortex dysfunction and correlates with cognitive impairment.The authors acknowledge funding from the European Union Horizon 2020 research and innovation program under Grant Agreement No. 668863 (SyBil-AA), and the Spanish Ministerio de Ciencia e Innovación, Agencia Estatal de Investigación (PID2021-128158NB-C21 [to S.C.] and PID2021-128909NA-I00 [to S.D.S.]) and Programs for Centres of Excellence in R&D Severo Ochoa (CEX2021-001165-S [to S.C. and S.D.S.]), the Spanish Generalitat Valenciana Government (PROMETEO/2019/015 [to SC] and CIDEGENT/2021/015 [to SDS]), the Spanish Ministerio de Sanidad, Servicios Sociales e Igualdad (#2021I082). W.H.S., F.K. and P.K. further acknowledge funding by the Deutsche Forschungs Gesellschaft through the Collaborative research Center grant TRR265 EnCoDe [138]. F.K. and P.K. also acknowledge funding by the Deutsche Forschungs Gesellschaft through the Collaborative Research Center SFB636 (Project D6). Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature.Pérez-Cervera, L.; De Santis, S.; Marcos, E.; Ghorbanzad-Ghaziany, Z.; Trouvé-Carpena, A.; Selim, MK.; Pérez-Ramírez, Ú.... (2023). Alcohol-induced damage to the fimbria/fornix reduces hippocampal-prefrontal cortex connection during early abstinence. Acta Neuropathologica Communications. 11(1):1-21. https://doi.org/10.1186/s40478-023-01597-812111

Effect of passive flow control on the aerodynamic performance, entropy generation and aeroacoustic noise of axial turbines for wave energy extractor

Wells turbine is the simplest type of an axial flow self-rectifying air turbine that can be used in conjunction with Oscillating Water Column (OWC) system in the extraction of ocean wave energy. It has been noticed that this turbine is subjected to early stall. As a consequence, several attempts for improving the energy extraction performance of Wells turbine within the stall regime have been investigated. One of these attempts was using an inclined slot as a passive flow control to obtain a delayed stall. In the following study, the impact of varying the angle for the slot on the performance of Wells turbine in the stall regime was investigated. Furthermore, the first law of thermodynamics and the entropy analysis has been used to examine the effect of the slot angle on the entropy generation features around the turbine blade. Moreover, Investigation of slot angle effect on the aerodynamics noise emission from Wells turbine airfoil during the normal operation and the stall regime is covered in this study. The blade of turbine with optimum angle of slot was investigated using the OWC based on actual data from the Egyptian Northern Coast. It was found that the optimum slot angle is 10° clockwise which results in 3% improvement in the torque coefficient before the stall and 15% after the stall as compared to the 0° slot. Otherwise, it gives a lower global entropy generation rate than the 0° slot by 4% before the stall and 3% after the stall. Furthermore, using airfoil of blade turbine with a slot resulted in a reduction of aeroacoustic noise by −21.2% at the stall regime under oscillating flow conditions. © 2018 Elsevier Lt

Sex matters: The MouseX DW-ALLEN Atlas for mice diffusion-weighted MR imaging

Overcoming sex bias in preclinical research requires not only including animals of both sexes in the experiments, but also developing proper tools to handle such data. Recent work revealed sensitivity of diffusion-weighted MRI to glia morphological changes in response to inflammatory stimuli, opening up exciting possibilities to characterize inflammation in a variety of preclinical models of pathologies, the great majority of them available in mice. However, there are limited resources dedicated to mouse imaging, like those required for the data processing and analysis. To fill this gap, we build a mouse MRI template of both structural and diffusion contrasts, with anatomical annotation according to the Allen Mouse Brain Atlas, the most detailed public resource for mouse brain investigation. To achieve a standardized resource, we use a large cohort of animals in vivo, and include animals of both sexes. To prove the utility of this resource to integrate imaging and molecular data, we demonstrate significant association between the mean diffusivity from MRI and gene expression-based glia density. To demonstrate the need of equitable sex representation, we compared across sexes the warp fields needed to match a male-based template, and our template built with both sexes. Then, we use both templates for analysing mice imaging data obtained in animals of different ages, demonstrating that using a male-based template creates spurious significant sex effects, not present otherwise. All in all, our MouseX DW-ALLEN Atlas will be a widely useful resource getting us one step closer to equitable healthcare

Alcohol-induced damage to the fimbria/fornix reduces hippocampal-prefrontal cortex connection during early abstinence

Abstract Introduction Alcohol dependence is characterized by a gradual reduction in cognitive control and inflexibility to contingency changes. The neuroadaptations underlying this aberrant behavior are poorly understood. Using an animal model of alcohol use disorders (AUD) and complementing diffusion-weighted (dw)-MRI with quantitative immunohistochemistry and electrophysiological recordings, we provide causal evidence that chronic intermittent alcohol exposure affects the microstructural integrity of the fimbria/fornix, decreasing myelin basic protein content, and reducing the effective communication from the hippocampus (HC) to the prefrontal cortex (PFC). Using a simple quantitative neural network model, we show how disturbed HC-PFC communication may impede the extinction of maladaptive memories, decreasing flexibility. Finally, combining dw-MRI and psychometric data in AUD patients, we discovered an association between the magnitude of microstructural alteration in the fimbria/fornix and the reduction in cognitive flexibility. Overall, these findings highlight the vulnerability of the fimbria/fornix microstructure in AUD and its potential contribution to alcohol pathophysiology. Summary Fimbria vulnerability to alcohol underlies hippocampal-prefrontal cortex dysfunction and correlates with cognitive impairment