Morrowpost5457

The ability of the olfactory system to detect and discriminate a broad spectrum of odor molecules with extraordinary sensitivity relies on a wide range of odorant receptors and on the distinct architecture of neuronal circuits in olfactory brain areas. More than 1000 odorant receptors, distributed almost randomly in the olfactory epithelium, are plotted out in two mirror-symmetric maps of glomeruli in the olfactory bulb, the first relay station of the olfactory system. How does such a precise spatial arrangement of glomeruli emerge from a random distribution of receptor neurons? Remarkably, the identity of odorant receptors defines not only the molecular receptive range of sensory neurons but also their glomerular target. Despite their key role, odorant receptors are not the only determinant, since the specificity of neuronal connections emerges from a complex interplay between several molecular cues and electrical activity. This review provides an overview of the mechanisms underlying olfactory circuit formation. In particular, recent findings on the role of odorant receptors in regulating axon targeting and of spontaneous activity in the development and maintenance of synaptic connections are discussed.Osteoarthritis (OA) is the most common joint disease with an unsatisfactory therapy outcome and characterized by the degradation of articular cartilage and synovial inflammation. Here, we isolated bone marrow mesenchymal stem cells (BMSCs) from rat's bone marrow and BMSC-derived exosome (BMSCs-Exo) from BMSCs successfully. MiR-135b was proved to be highly expressed in TGF-β1-stimulated BMSC-derived exosomes (BMSCs-ExoTGF-β1). Then, our results demonstrated that BMSCs-ExoTGF-β1 reduced OA-induced upregulation of pro-inflammatory factors in rat's serum and damage in cartilage tissues, which was then reversed by miR-135b decreasing. Subsequently, we found that the OA-resulted M1 polarization of synovial macrophages (SMs) was repressed by BMSCs-ExoTGF-β1, this effect of BMSCs-ExoTGF-β1 was limited by miR-135b decreasing. We also proved that M2 polarization of SMs can be induced by miR-135b mimics. this website Furthermore, we found that the promotory effect of miR-135b and BMSCs-ExoTGF-β1 on M2 SMs polarization was reversed by increasing of MAPK6. Overall, our data showed that BMSCs-ExoTGF-β1 attenuated cartilage damage in OA rats through carrying highly expressed miR-135b. Mechanistically, miR-135b promoted M2 polarization of SMs through targeting MAPK6, thus improving cartilage damage. Our study provided a novel regulatory mechanism of BMSCs-Exo in OA development and revealed a new potential treatment target of OA.The nasal cavity of tetrapods has become phylogenetically adapted to the environment in terms of function, respiration, and olfaction. In addition, the nasal cavity of sea turtles plays an important role in seawater flow and water olfaction, unlike that of terrestrial species. Here, we describe the functional, morphological, and histological characteristics of the nasal cavity, and the odorant receptors encoded in the genome of sea turtles. The nasal cavity of sea turtles is well-suited to its complicated functions, and it significantly differs from those of other animals, including terrestrial and semi-aquatic turtles.In teleost fish, specialized oxygen (O2) chemoreceptors, called neuroepithelial cells (NECs), are found in the gill epithelium in adults. During development, NECs are present in the skin before the formation of functional gills. NECs are known for retaining the monoamine neurotransmitter, serotonin (5-HT) and are conventionally identified through immunoreactivity with antibodies against 5-HT or synaptic vesicle protein (SV2). However, identification of NECs in live tissue and isolated cell preparations has been challenging due to the lack of a specific marker. The present study explored the use of the transgenic zebrafish, ETvmat2GFP, which expresses green fluorescent protein (GFP) under the control of the vesicular monoamine transporter 2 (vmat2) regulatory element, to identify NECs. Using immunohistochemistry and confocal microscopy, we confirmed that the endogenous GFP in ETvmat2GFP labelled serotonergic NECs in the skin of larvae and in the gills of adults. NECs of the gill filaments expressed a higher level of endogenous GFP compared with other cells. The endogenous GFP also labelled intrabranchial neurons of the gill filaments. Flow cytometric analysis demonstrated that filamental NECs could be distinguished from other dissociated gill cells based on high GFP expression alone. Acclimation to 2 weeks of severe hypoxia (PO2 = 35 mmHg) induced an increase in filamental NEC frequency, size and GFP gene expression. Here we present for the first time a transgenic tool that labels O2 chemoreceptors in an aquatic vertebrate and its use in high-throughput experimentation.Appropriate perception and representation of sensory stimuli pose an everyday challenge to the brain. In order to represent the wide and unpredictable array of environmental stimuli, principle neurons of associative learning regions receive sparse, combinatorial sensory inputs. Despite the broad role of such networks in sensory neural circuits, the developmental mechanisms underlying their emergence are not well understood. As mammalian sensory coding regions are numerically complex and lack the accessibility of simpler invertebrate systems, we chose to focus this review on the numerically simpler, yet functionally similar, Drosophila mushroom body calyx. We bring together current knowledge about the cellular and molecular mechanisms orchestrating calyx development, in addition to drawing insights from literature regarding construction of sparse wiring in the mammalian cerebellum. From this, we formulate hypotheses to guide our future understanding of the development of this critical perceptual center.Alcoholic fermentation is a crucial step of winemaking, during which yeasts convert sugars to alcohol and also produce or biotransform numerous flavour compounds. In this context, nutrients are essential compounds to support yeast growth and ultimately ensure complete fermentation, as well as optimized production of flavour compounds over that of off-flavour compounds. In particular, the vitamin thiamine not only plays an essential cofactor role for several enzymes involved in various metabolic pathways, including those leading to the production of wine-relevant flavour compounds, but also aids yeast survival via thiamine-dependent stress protection functions. Most yeast species are able to both assimilate exogenous thiamine into the cell and synthesize thiamine de novo. However, the mechanism and level of thiamine accumulation depend on several factors. This review provides an in-depth overview of thiamine utilization and metabolism in the model yeast species Saccharomyces cerevisiae, as well as the current knowledge on (1) the intracellular functions of thiamine, (2) the balance between and regulation of uptake and synthesis of thiamine and (3) the multitude of factors influencing thiamine availability and utilization.