Anatomical and functional investigation of the deep medial entorhinal cortex

Spatial computations are thought to be processed in the hippocampal-entorhinal network and involve neurons with spatially selective firing properties. The deep medial entorhinal cortex (MEC) consists of molecularly distinct sublayers with distinct connectivity. One of these layers, layer 5b (L5b) receives input both from the hippocampal cornu ammonis 1 (CA1) area and the superficial MEC, regions that have abundant spatially selective cells. Extracellular recordings from rats found grid and conjunctive cells in the deep MEC, while other studies suggest that deep MEC neurons are silent. Based on its position in the circuit and the presence of spatial cells, I hypothesized that L5b plays a role in spatial cognition. To test this hypothesis, I first investigated approaches to target L5b cells with genetic precision and characterized transgenic mouse lines. I found a mouse line that had tTA expression sufficiently specific to L5b, and used this line to investigate the anatomy and firing properties of L5b cells. I developed an analysis pipeline to automate the analysis of extracellular recordings using MountainSort, and evaluated opto-tagging of genetically defined cells in an open field arena. I successfully opto-tagged one genetically defined deep layer cell and a small number of cells that receive input from genetically defined deep layer cells. My analysis of the firing properties of deep MEC cells recorded from mice indicates that grid and head-direction properties are similar to what was reported in the rat. My results support the idea that deep layers of MEC have a powerful influence on more superficial layers and suggest how cells in this area may contribute to spatial behaviours

Szemelvények a katonai víztisztítási kutatásokból (az 1970-es és '80-as évek), különös tekintettel a fordított ozmózis alkalmazására I. rész

Retrato de un hombre y una mujer, en un patio interior. Él posa de pie, ella posa sentada en una silla

Grid cells are modulated by local head direction

Neurons with grid firing fields are thought to play important roles in spatial cognition. Here, the authors show that in contrast to assumptions underlying current models and analyses, grid fields are modulated by local head direction; this suggests different mechanisms and new roles for grid firing

Manufacturing of Large Size and Polished Ceramic Pistons by Cold Isostatic Pressing

This paper discusses the challenges involved in producing high-quality alumina ceramics, particularly when it comes to achieving a proper surface roughness and accuracy. Alumina ceramics are widely used in various applications due to their exceptional properties, including high strength, wear resistance, and chemical stability. The alumina pistons with the desired properties and performance were produced from commercially available raw materials. To improve the densification and mechanical properties of the sintered ceramics organic binder were used. The use of diamond abrasive slurry polishing was studied also, which has been shown to be particularly effective in achieving a high degree of surface finish. The study aims to produce alumina-based pistons with low surface roughness, and the paper discusses the techniques and methods used to achieve this goal. The results of the study include the porosity, mechanical properties, and microstructure of the alumina ceramics produced, as well as the effectiveness of the techniques and methods used

Recurrence of primary sclerosing cholangitis after liver transplantation: the Hungarian experience

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Non-anastomotic biliary strictures after liver transplantation : Focus on percutaneous treatment and extent of disease

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