Supramammillary Nucleus Afferents to the Dentate Gyrus Co-release Glutamate and GABA and Potentiate Granule Cell Output

Summary: The supramammillary nucleus (SuM) of the hypothalamus projects to the dentate gyrus (DG) and the CA2 region of the hippocampus. Although the SuM-to-hippocampus circuits have been implicated in spatial and emotional memory formation, little is known about precise neural connections between the SuM and hippocampus. Here, we report that axons of SuM neurons make monosynaptic connections to granule cells (GCs) and GABAergic interneurons, but not to hilar mossy cells, in the DG and co-release glutamate and γ-aminobutyric acid (GABA) at these synapses. Although inputs from the SuM can excite some interneurons, the inputs alone fail to generate spikes in GCs. However, despite the insufficient excitatory drive and GABAergic co-transmission, SuM inputs have net excitatory effects on GCs and can potentiate GC firing when temporally associated with perforant path inputs. Our results indicate that the SuM influences DG information processing by modulating GC outputs. : The supramammillary nucleus (SuM)-to-hippocampus network is implicated in spatial and emotional memory formation, but little is known about precise neural connections. Hashimotodani et al. show that SuM afferents to the dentate gyrus co-release glutamate and GABA, evoke monosynaptic responses in granule cells (GCs) and GABAergic interneurons, and facilitate GC output. Keywords: hippocampus, dentate gyrus, supramammillary nucleus, co-release, granule cell, interneuron, mossy cell, glutamate, GABA, perforant pat

新しい市場カテゴリーはどのように誕生するか : 低糖質市場の形成史

個別企業の戦略行動と産業レベルの市場形成はいかに相互に作用しながらイノベーションに結実するのか。本研究の目的は、カテゴリー論を援用しながら、低糖質市場の形成過程を個別企業の取り組みや製品動向、消費者による関連用語の利用に関するデータを通じて検討し、この問いに回答を導き出すことにある。カテゴリー論では、カテゴリーの境界や意味の曖昧さが、多様な企業や製品の参入を促し新規カテゴリーの形成を促進すると論じられている。本稿では、低糖質市場においても同様のメカニズムが働いたことを確認する。すなわち、マクロレベルでは標準的な基準や制度がないことが、ミクロレベルでの多様な企業や製品がカテゴリーへ参入を促し、その結果マクロレベルでは境界や意味が曖昧な市場カテゴリーの形成に寄与し、さらなる多様な企業や製品の参入を促すという一連のメカニズムである。How do the strategic actions of individual firms and market formation at the industry level interact to result in innovation? The purpose of this study is to answer this question by examining the formation process of low-carbohydrate markets through data on individual firms' initiatives, product trends, and consumers' use of related terms, with the aid of category theory. Category theory argues that the ambiguity of category boundaries and meanings encourages the entry of diverse companies and products and the formation of new categories. This paper confirms that a similar mechanism worked in the low-carbohydrate market. That is, a series of mechanisms in which the lack of standardized criteria and institutions at the macro level encourages diverse firms and products to enter a category at the micro level, which in turn contributes to the formation of market categories with ambiguous boundaries and meanings at the macro level and encourages the entry of even more diverse firms and products

descSPIM: an affordable and easy-to-build light-sheet microscope optimized for tissue clearing techniques

Abstract Despite widespread adoption of tissue clearing techniques in recent years, poor access to suitable light-sheet fluorescence microscopes remains a major obstacle for biomedical end-users. Here, we present descSPIM (desktop-equipped SPIM for cleared specimens), a low-cost ($20,000–50,000), low-expertise (one-day installation by a non-expert), yet practical do-it-yourself light-sheet microscope as a solution for this bottleneck. Even the most fundamental configuration of descSPIM enables multi-color imaging of whole mouse brains and a cancer cell line-derived xenograft tumor mass for the visualization of neurocircuitry, assessment of drug distribution, and pathological examination by false-colored hematoxylin and eosin staining in a three-dimensional manner. Academically open-sourced ( https://github.com/dbsb-juntendo/descSPIM ), descSPIM allows routine three-dimensional imaging of cleared samples in minutes. Thus, the dissemination of descSPIM will accelerate biomedical discoveries driven by tissue clearing technologies