Purinergic receptor-mediated Ca2+ signaling in the olfactory bulb and the neurogenic area of the lateral ventricles

Like in other vertebrates, the anterior part of the telencephalon of amphibians mainly consists of the olfactory bulb (OB), but different from higher vertebrates, the lateral telencephalic ventricles of larval Xenopus laevis expand deep into the anterior telencephalon. The neurogenic periventricular zone (PVZ) of the lateral ventricles generates new OB neurons throughout the animal’s lifetime. We investigated the ultrastructural organization of the PVZ and found that within a time period of 24 h, 42.54 ± 6.65% of all PVZ cells were actively proliferating. Functional purinergic receptors are widespread in the central nervous system and their activation has been associated with many critical physiological processes, including the regulation of cell proliferation. In the present study we identified and characterized the purinergic system of the OB and the PVZ. ATP and 2MeSATP induced strong [Ca2+]i increases in cells of both regions, which could be attenuated by purinergic antagonists. However, a more thorough pharmacological investigation revealed clear differences between the two brain regions. Cells of the OB almost exclusively express ionotropic P2X purinergic receptor subtypes, whereas PVZ cells express both ionotropic P2X and metabotropic P1 and P2Y receptor subtypes. The P2X receptors expressed in the OB are evidently not involved in the immediate processing of olfactory information

Conservation of Glomerular Organization in the Main Olfactory Bulb of Anuran Larvae

The glomerular array in the olfactory bulb of many vertebrates is segregated into molecularly and anatomically distinct clusters linked to different olfactory functions. In anurans, glomerular clustering is so far only described in Xenopus laevis. We traced olfactory projections to the bulb in tadpoles belonging to six distantly related anuran species in four families (Pipidae, Hylidae, Bufonidae, Dendrobatidae) and found that glomerular clustering is remarkably conserved. The general bauplan consists of four unequally sized glomerular clusters with minor inter-species variation. During metamorphosis, the olfactory system undergoes extensive remodeling. Tracings in metamorphotic and juvenile Dendrobates tinctorius and Xenopus tropicalis suggest a higher degree of variation in the glomerular organization after metamorphosis is complete. Our study highlights, that the anatomical organization of glomeruli in the main olfactory bulb (MOB) is highly conserved, despite an extensive ecomorphological diversification among anuran tadpoles, which suggests underlying developmental constraints.Fil: Weiss, Lukas. Justus Liebig Universitat Giessen; AlemaniaFil: Jungblut, Lucas David. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; ArgentinaFil: Pozzi, Andrea Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: O´Connell, Lauren A.. University of Stanford; Estados UnidosFil: Hassenklöver, Thomas. Justus Liebig Universitat Giessen; AlemaniaFil: Manzini, Ivan. Justus Liebig Universitat Giessen; Alemani

Coordinated shift of olfactory amino acid responses and V2R expression to an amphibian water nose during metamorphosis

All olfactory receptors identified in teleost fish are expressed in a single sensory surface, whereas mammalian olfactory receptor gene families segregate into different olfactory organs, chief among them the main olfactory epithelium expressing ORs and TAARs, and the vomeronasal organ expressing V1Rs and V2Rs. A transitional stage is embodied by amphibians, with their vomeronasal organ expressing more 'modern', later diverging V2Rs, whereas more 'ancient', earlier diverging V2Rs are expressed in the main olfactory epithelium. During metamorphosis, the main olfactory epithelium of Xenopus tadpoles transforms into an air-filled cavity (principal cavity, air nose), whereas a newly formed cavity (middle cavity) takes over the function of a water nose. We report here that larval expression of ancient V2Rs is gradually lost from the main olfactory epithelium as it transforms into the air nose. Concomitantly, ancient v2r gene expression begins to appear in the basal layers of the newly forming water nose. We observe the same transition for responses to amino acid odorants, consistent with the hypothesis that amino acid responses may be mediated by V2R receptors

Bromophenols in Marine Algae and Their Bioactivities

Marine algae contain various bromophenols that have been shown to possess a variety of biological activities, including antioxidant, antimicrobial, anticancer, anti-diabetic, and anti-thrombotic effects. Here, we briefly review the recent progress of these marine algal biomaterials, with respect to structure, bioactivities, and their potential application as pharmaceuticals

Klassifikation hochvarianter Muster mit Faltungsnetzwerken

Die Klassifizierung von Objekten und besonders des Menschen durch Software stellt sich schon seit Jahren als schwer lösbares Problem heraus. Diese hochvarianten Formen werden optisch erfasst und bisher häufig mit Neuronalen Netzwerken in Kombination mit statistischen Verfahren erfasst. Eine neue Methode zur Erkennung von hochvarianten Mustern, wie Schriftzeichen, Gegenständen oder Menschen sind Faltungsnetzwerke. Faltungsnetzwerke sind eine Abart von Neuronalen Netzwerken, die ihre Entscheidungen auf Basis von Algorithmen aus der Bildverarbeitung treffen. In dieser Arbeit werden die Grenzen der Erkennung der Faltungsnetzwerke getestet. In Tests mit unterschiedlich modifizierten Eingabedaten wird die Auswirkung auf die Klassifizierungsgenauigkeit geprüft.The classification of objects and especially of humans by software is for years a great challenge. These highly variant forms are optically captured and often detected with the use of neural networks in combination with statistical methods. A new method for the detection of these highly variant patterns, such as characters, objects or people are Convolutional neural networks. Convolutional neural networks are a variety of Neural networks, which make their decisions based on algorithms used in image processing. In this thesis the limits of the detection of Convolutional neural networks are tested. In the tests the impact on the classification accuracy is checked with various modified input data

Code and Data for "S100Z is expressed in a lateral subpopulation of olfactory receptor neurons in the main olfactory system of Xenopus laevis"

This repository contains Python scripts that were used to analyze the distribution of manually identified cells in the olfactory system. Multiphoton microscopy image stacks of immunohistochemically labeled olfactory system tissue were manually annotated using the ImageJ ROI Manager tool. Regions of interest were exported from ImageJ as roi-files (provided as zip-archive). We include two datasets that were analyzed using these scripts. The datasets comprise of the imported ROI informations, experiment metadata, and results of calculations performed with the Python scripts. code.py: Script collection to analyze regions of interest drawn using the ImageJ ROI Manager tool. rois_from_imagej.zip: Roi-files exported from ImageJ. Subfolders contain s100z/biocytin labeled cells in different samples. biocytin_cell_counts.csv: Dataset of biocytin-backfilled olfactory receptor neurons s100z_cell_counts.csv: Dataset of human S100Z antibody labeled cellsDeutsche Forschungsgemeinschaft (DFG); ROR-ID:018mejw6

Olfaction across the water–air interface in anuran amphibians

Deutsche Forschungsgemeinschaft (DFG); ROR-ID:018mejw6