29 research outputs found
Imaging pheromone sensing in a mouse vomeronasal acute tissue slice preparation.
Peter Karlson and Martin LĂŒscher used the term pheromone for the first time in 1959 to describe chemicals used for intra-species communication. Pheromones are volatile or non-volatile short-lived molecules secreted and/or contained in biological fluids, such as urine, a liquid known to be a main source of pheromones. Pheromonal communication is implicated in a variety of key animal modalities such as kin interactions, hierarchical organisations and sexual interactions and are consequently directly correlated with the survival of a given species. In mice, the ability to detect pheromones is principally mediated by the vomeronasal organ (VNO), a paired structure located at the base of the nasal cavity, and enclosed in a cartilaginous capsule. Each VNO has a tubular shape with a lumen allowing the contact with the external chemical world. The sensory neuroepithelium is principally composed of vomeronasal bipolar sensory neurons (VSNs). Each VSN extends a single dendrite to the lumen ending in a large dendritic knob bearing up to 100 microvilli implicated in chemical detection. Numerous subpopulations of VSNs are present. They are differentiated by the chemoreceptor they express and thus possibly by the ligand(s) they recognize. Two main vomeronasal receptor families, V1Rs and V2Rs, are composed respectively by 240 and 120 members and are expressed in separate layers of the neuroepithelium. Olfactory receptors (ORs) and formyl peptide receptors (FPRs) are also expressed in VSNs. Whether or not these neuronal subpopulations use the same downstream signalling pathway for sensing pheromones is unknown. Despite a major role played by a calcium-permeable channel (TRPC2) present in the microvilli of mature neurons TRPC2 independent transduction channels have been suggested. Due to the high number of neuronal subpopulations and the peculiar morphology of the organ, pharmacological and physiological investigations of the signalling elements present in the VNO are complex. Here, we present an acute tissue slice preparation of the mouse VNO for performing calcium imaging investigations. This physiological approach allows observations, in the natural environment of a living tissue, of general or individual subpopulations of VSNs previously loaded with Fura-2AM, a calcium dye. This method is also convenient for studying any GFP-tagged pheromone receptor and is adaptable for the use of other fluorescent calcium probes. As an example, we use here a VG mouse line, in which the translation of the pheromone V1rb2 receptor is linked to the expression of GFP by a polycistronic strategy
Spider Movement, UV Reflectance and Size, but Not Spider Crypsis, Affect the Response of Honeybees to Australian Crab Spiders
According to the crypsis hypothesis, the ability of female crab spiders to change body colour and match the colour of flowers has been selected because flower visitors are less likely to detect spiders that match the colour of the flowers used as hunting platform. However, recent findings suggest that spider crypsis plays a minor role in predator detection and some studies even showed that pollinators can become attracted to flowers harbouring Australian crab spider when the UV contrast between spider and flower increases. Here we studied the response of Apis mellifera honeybees to the presence of white or yellow Thomisus spectabilis Australian crab spiders sitting on Bidens alba inflorescences and also the response of honeybees to crab spiders that we made easily detectable painting blue their forelimbs or abdomen. To account for the visual systems of crab spider's prey, we measured the reflectance properties of the spiders and inflorescences used for the experiments. We found that honeybees did not respond to the degree of matching between spiders and inflorescences (either chromatic or achromatic contrast): they responded similarly to white and yellow spiders, to control and painted spiders. However spider UV reflection, spider size and spider movement determined honeybee behaviour: the probability that honeybees landed on spider-harbouring inflorescences was greatest when the spiders were large and had high UV reflectance or when spiders were small and reflected little UV, and honeybees were more likely to reject inflorescences if spiders moved as the bee approached the inflorescence. Our study suggests that only the large, but not the small Australian crab spiders deceive their preys by reflecting UV light, and highlights the importance of other cues that elicited an anti-predator response in honeybees
Innovative Analysis of X-ray Microdiffraction Images on Selected Applications of the Kossel Technique
Starting from the origin and the informational content of Kossel interferences excited by electron and synchrotron radiation beams selected examples of microstructural applications, such as the precision determination of lattice constants, the precision determination of crystallographic orientation of single grains, the determination of local stresses/strains and the determination of tetragonal distortions of cubic lattices including the description of a variety of methods for analysis are presented
Enzootic nasal adenocarcinoma in dairy sheep
International audienceIn a herd of dairy sheep several losses occurred due to a respiratory syndrome in combination with progressive wasting. Clinical and pathomorphological diagnostics of 3 sheep revealed the presence of cancerous masses in the nasal cavities. These neoplasms were identified as adenocarcinomas originating from the nasal mucosa. Etiologically, they were attributed to JRSV (Jaagsiekte Sheep Retrovirus) by detection of capsid protein 24 in western blot. The significance of the disease in Switzerland is discussed, also in the context of lung adenomatosis.Plusieurs cas de difficultĂ©s respiratoires accompagnĂ©es dâun amaigrissement progressif sont apparus en 6 mois dans un troupeau de brebis laitiĂšres dâenviron 80 tĂȘtes. Par des examens cliniques et anatomopathologiques, le problĂšme a pu ĂȘtre attribuĂ© chez 3 animaux Ă un processus prolifĂ©ratif dans les fosses nasales. Lâagent Ă©tiologique de ces adĂ©nocarcinomes de la muqueuse nasale a Ă©tĂ© diagnostiquĂ© au moyen dâun western blot dans le matĂ©riel tumoral comme Ă©tant le retrovirus Jaagsiekte Sheep (JRSV). Lâimportance de lâapparition de cette maladie chez les moutons en Suisse et son rapport avec lâadenomatose pulmonaire sont discutĂ©s
Targeting Trained Innate Immunity With Nanobiologics to Treat Cardiovascular Disease
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Measuring body structures and body functions from the International Classification of Functioning, Disability, and Health perspective: considerations for biomedical parameters in spinal cord injury research
OBJECTIVE:
The aims of this study were to provide a selection of biomedical domains based on the comprehensive International Classification of Functioning, Disability, and Health (ICF) core sets for spinal cord injury (SCI) and to present an overview of the corresponding measurement instruments.
DESIGN:
Based on the Biomedical Domain Set, the SCI literature, the International Spinal Cord Society international data sets, and the Spinal Cord Injury Rehabilitation Evidence project publications were used to derive category specifications for use in SCI research. Expert opinion was used to derive a priority selection. The same sources were used to determine candidate measurement instruments for the specification of body functions and body structures using an example, and guiding principles were applied to select the most appropriate biomedical measurement instrument(s) for use in an SCI research project.
RESULTS:
Literature searches were performed for 41 second-level ICF body functions categories and for four second-level ICF body structures categories. For some of these categories, only a few candidate measurement instruments were found with limited variation in the type of measurement instruments.
CONCLUSIONS:
An ICF-based measurement set for biomedical aspects of functioning with SCI was established. For some categories of the ICF core sets for SCI, there is a need to develop measurement instruments