The Experts below are selected from a list of 66732 Experts worldwide ranked by ideXlab platform
David Lecchini - One of the best experts on this subject based on the ideXlab platform.
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Ecological determinants and Sensory Mechanisms in habitat selection of crustacean postlarvae
Behavioral Ecology, 2010Co-Authors: David Lecchini, Suzanne C. Mills, Christophe Brié, Robert Maurin, Bernard BanaigsAbstract:Animals use Sensory stimuli to assess and select habitats, mates, and food as well as to communicate with other individuals. One of the great mysteries of crustacean ecology is how postlarvae locate the relatively rare patches of coral reef habitat on which they settle. The present study aimed to estimate, by experiments in aquaria and biochemical analysis, the Sensory modalities of crustacean postlarvae for senses used in searching for their species' settlement habitat. The study was carried out on 9 crustacean species (Calappa calappa, Pachygrapsus planifrons, Xanthidae sp., Lysiosquillina maculata, L. sulcata, Raoulserenea sp., Stenopus hispidus, Palaemonidae sp., and Panulirus penicillatus). For each species, a cohort of 30 postlarvae was captured on the same night on the reef crest of Rangiroa Atoll (French Polynesia). Among the 9 crustacean species studied, 6 made active habitat choices among the 4 habitats tested (live coral, dead coral, macroalgae, and sand) at the postlarval stage, but the presence or absence of conspecifics on the habitat did not influence their selective choice. Sensory experiments found that 4 species differentiated between their preferred habitat versus another habitat and 2 species differentiated between conspecifics and heterospecifics, using visual and/or olfactory cues. Lastly, the high performance liquid chromatography experiments showed that the 4 habitats and conspecifics (except L. maculata and S. hispidus) tested have different and unique chemical odors. Overall, our study is the first to highlight the Sensory modalities for a broad range of crustacean species to detect and move toward settlement habitats and/or conspecifics. Copyright 2010, Oxford University Press.
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Ontogenetic changes in habitat selection during settlement in a coral reef fish: ecological determinants and Sensory Mechanisms
Coral Reefs, 2007Co-Authors: David Lecchini, J. S. Shima, C. M. St Mary, Craig W Osenberg, Rene GalzinAbstract:The behavior of marine larvae during and after settlement can help shape the distribution and abundance of benthic juveniles and therefore the intensity of ecological interactions on reefs. Several laboratory choice-chamber experiments were conducted to explore Sensory capabilities and behavioral responses to ecological stimuli to better understand habitat selection by “pre-metamorphic” (larval) and “post-metamorphic” (juvenile) stages of a coral reef fish ( Thalassoma hardwicke ). T. hardwicke larvae were attracted to benthic macroalgae ( Turbinaria ornata and Sargassum mangarevasae ), while slightly older post-metamorphosed juveniles chose to occupy live coral colonies ( Pocillopora damicornis ). Habitat choices of larvae were primarily based upon visual cues and were not influenced by the presence of older conspecifics. In contrast, juveniles selected live coral colonies and preferred those occupied by older conspecifics; choices made by juveniles were based upon both visual and olfactory cues from conspecifics. Overall, the laboratory experiments suggest that early life-history stages of T. hardwicke use a range of Sensory modalities that vary through ontogeny, to effectively detect and possibly discriminate among different microhabitats for settlement and later occupation. Habitat selection, based upon cues provided by environmental features and/or by conspecifics, might have important consequences for subsequent competitive interactions.
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larval Sensory abilities and Mechanisms of habitat selection of a coral reef fish during settlement
Oecologia, 2005Co-Authors: J. S. Shima, David Lecchini, Bernard Banaigs, Rene GalzinAbstract:Sensory abilities and preferences exhibited by mobile larvae during their transition to juvenile habitats can establish spatial heterogeneity that drives subsequent species interactions and dynamics of populations. We conducted a series of laboratory and field experiments using coral reef fish larvae (Chromis viridis) to determine: ecological determinants of settlement choice (conspecifics vs. heterospecifics vs. coral substrates); Sensory Mechanisms (visual, acoustic/vibratory, olfactory) underlying settlement choice; and Sensory abilities (effective detection distances of habitat) under field conditions. C. viridis larvae responded positively to visual, acoustic/vibratory, and olfactory cues expressed by conspecifics. Overall, larvae chose compartments of experimental arenas containing conspecifics in 75% of trials, and failed to show any significant directional responses to heterospecifics or coral substrates. In field trials, C. viridis larvae detected reefs containing conspecifics using visual and/or acoustic/vibratory cues at distances <75 cm; detection distances increased to <375 cm when olfactory capacity was present (particularly for reefs located up-current). We conducted high performance liquid chromatography (HPLC) analyses of seawater containing C. viridis juveniles and isolated high concentrations of several organic compounds. Subsequent laboratory trials demonstrated that C. viridis larvae responded positively to only one of these organic compounds. This compound was characterized by a weak polarity and was detected at 230 nm with a 31-min retention time in HPLC. Overall, our results suggest that fishes may use a range of Sensory Mechanisms effective over different spatial scales to detect and choose settlement sites, and species-specific cues may play a vital role in establishment of spatial patterns at settlement.
Ellen A. Lumpkin - One of the best experts on this subject based on the ideXlab platform.
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Sensory Mechanisms in Mammalian Touch Receptor Cells
Biophysical Journal, 2011Co-Authors: Ellen A. LumpkinAbstract:The sense of touch is critical for hand dexterity that allows mammals to recognize and grasp objects. Different qualities of touch are encoded by Sensory neurons with distinct properties. Shapes and curvature are encoded by Merkel cell-neurite complexes, which mediate slowly adapting type I (SAI) responses. Merkel cells, which cluster in fingertips and other highly touch-sensitive skin areas, are enigmatic epidermal cells first described in 1875. The role that these cells play in SAI responses has been debated for 40 years.Based on morphology, Merkel cells are proposed to be mechanoSensory cells. If so, Merkel cells should 1) transduce force into membrane-potential changes that gate voltage-activated ion channels and 2) signal afferent neurons through synaptic transmission. Functional studies testing these predictions in intact skin have produced conflicting results. To tackle these questions, my laboratory uses a combination of mouse genetics, in vitro systems and intact electrophysiological recordings. Our in vitro studies have demonstrated that Merkel cells are intrinsically force-sensitive and that voltage-activated channels open downstream of mechanical stimuli. Moreover, Merkel cells express numerous ion channels and presynaptic proteins. Collectively, these results suggest that Merkel cells are capable of serving as touch receptor cells and pave the way to discover transduction Mechanisms.To determine whether Merkel cells are necessary for touch responses, we used Cre-loxP technology to generate mice that completely lack Merkel cells in the body skin. We then used an ex vivo skin-nerve preparation to survey the classes of touch-sensitive afferents in the saphenous nerve. Although we found no significant differences in nociceptive Sensory fibers, we observed a complete loss of SAI responses among light-touch receptors in mice lacking Merkel cells compared with wild-type mice. These results demonstrate that Merkel cells are required for appropriate Sensory coding of light touch.
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The Regularity of Sustained Firing Reveals Two Populations of Slowly Adapting Touch Receptors in Mouse Hairy Skin
Journal of neurophysiology, 2010Co-Authors: Scott A. Wellnitz, Daine R. Lesniak, Gregory J. Gerling, Ellen A. LumpkinAbstract:Touch is initiated by diverse somatoSensory afferents that innervate the skin. The ability to manipulate and classify receptor subtypes is prerequisite for elucidating Sensory Mechanisms. Merkel ce...
Lori A. Birder - One of the best experts on this subject based on the ideXlab platform.
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Heterogeneity of muscarinic receptor-mediated Ca2+ responses in cultured urothelial cells from rat.
American journal of physiology. Renal physiology, 2008Co-Authors: F. Aura Kullmann, William C. De Groat, Debra E. Artim, Jonathan M. Beckel, Stacey Barrick, Lori A. BirderAbstract:Muscarinic receptors (mAChRs) have been identified in the urothelium, a tissue that may be involved in bladder Sensory Mechanisms. This study investigates the expression and function of mAChRs usin...
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Mechanisms of disease: involvement of the urothelium in bladder dysfunction.
Nature Clinical Practice Urology, 2007Co-Authors: Lori A. Birder, William C. De GroatAbstract:Although the urinary bladder urothelium has classically been thought of as a passive barrier to ions and solutes, a number of novel properties have been recently attributed to urothelial cells. Studies have revealed that the urothelium is involved in Sensory Mechanisms (i.e. the ability to express a number of sensor molecules or respond to thermal, mechanical and chemical stimuli) and can release chemical mediators. Localization of afferent nerves next to the urothelium suggests that urothelial cells could be targets for neurotransmitters released from bladder nerves or that chemicals released by urothelial cells could alter afferent nerve excitability. Taken together, these and other findings highlighted in this article suggest a Sensory function for the urothelium. Elucidation of Mechanisms that influence urothelial function might provide insights into the pathology of bladder dysfunction.
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More than just a barrier: urothelium as a drug target for urinary bladder pain
American Journal of Physiology-renal Physiology, 2005Co-Authors: Lori A. BirderAbstract:Although the urinary bladder urothelium has classically been thought of as a passive barrier to ions/solutes, a number of novel properties have been recently attributed to these cells. Studies have revealed that the urothelium is involved in Sensory Mechanisms (i.e., ability to express a number of sensor molecules or respond to thermal, mechanical, and chemical stimuli) and can release chemical mediators. Localization of afferent nerves next to the urothelium suggests these cells may be targets for transmitters released from bladder nerves or that chemicals released by urothelial cells may alter afferent excitability. Taken together, these and other findings highlighted in this review suggest a Sensory function for the urothelium. Elucidation of Mechanisms impacting on urothelial function may provide insights into the pathology of bladder dysfunction.
Bernd Kramer - One of the best experts on this subject based on the ideXlab platform.
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Communication behavior and Sensory Mechanisms in weakly electric fishes
Advances in the Study of Behavior, 1994Co-Authors: Bernd KramerAbstract:Teleost freshwater fishes of the orders Mormyriformes (the elephantfishes plus Gymnarchus from Africa) and Gymnotiformes (the knifefishes from South America) are both electrogenic and electroreceptive. These fishes' electric system has a motor part, the electric organ, and a Sensory part, the cutaneous electroreceptors that project to large, specialized brain areas. The electric systems of both groups of fishes, although evolved independently, are adapted to the same two functions, nocturnal electrolocation and communication. Weakly electric fishes discharge their electric organs in a pulselike or in a wavelike fashion ("buzzers" and "hummers," respectively). Whether a species is a hummer or a buzzer does not appear to be correlated with ecology but is strongly linked to phylogeny. There are representatives of both discharge types on both continents where these fishes are found. The elephantfishes (Mormyridae, about 200 species) are, apparently, all pulse fishes, whereas the related, monospecific Gymnarchus (Gymnarchidae) is the only known African wave fish. There are five families of South American knifefishes, with the majority of the 70 or so species being hummers, usually discharging at extremely constant frequencies (about 50- 1800 Hz). The Sensory Mechanisms of social communication, as studied by behavioral means, are reviewed in this chapter with the question of Mechanisms of reproductive isolation in mind. The chapter focuses on the electric organ discharge as the basic communication unit, and on the frequency, repetition rate, or temporal patterns of discharges. In both wave and pulse fishes the frequencies or repetition rates of discharges are not usually species-specific but are species-characteristic, because of more or less broad overlap between two or more species (depending on the local community of species). ElectroSensory discrimination thresholds for frequency and intensity are unusually low in a wave fish, lower by far than those for other acoustico-lateral senses of aquatic lower vertebrates, rivaling the discrimination thresholds for audition in the most sensitive mammals (e.g., the human). A similar conclusion applies for the pulse rate sensitivity of a mormyrid. Species specificity becomes apparent when more information about the discharge activity is considered. In the case of pulse fishes, especially mormyrids, this comprises temporal patterns of discharges, which also vary greatly according to behavioral context (like aggression, escape, courtship, feeding, etc.); these fishes have an interdischarge interval code of communication. In the case of wave fishes, various types of frequency modulations and brief, repetitive discharge stops occur. Also, wave fishes may engage in "phase coupling" and "jamming avoidance," maneuvers that involve precise interaction with another fish's discharges. The degree ' of species specificity of a fish's discharge activity is usually enhanced by features of the waveform of a single discharge; this is true in both pulse and wave fishes. Usually there is considerable intraspecific variability of discharge waveforms, and there are also examples of sexual dimorphism. At least a few species can discriminate the individually variable pulse or wave discharge waveforms of their species. In a wave fish, a Sensory mechanism based on the temporal analysis of beat patterns can explain the observed results. This new Sensory capacity detects the phase modulation within a beat, which always occurs when the wave discharges of two fish mix in the water. In pulse fishes, several hypothetical Sensory Mechanisms for the discrimination of intraspecific pulse waveforms have been proposed but it is not yet clear which is generally involved. In any case, the sensitivity of weakly electric fishes to the fine detail of their discharges shows that the electroSensory world is much more colorful than could be imagined until recently.
Ashley J. W. Ward - One of the best experts on this subject based on the ideXlab platform.
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Shoaling fish can size-assort by chemical cues alone
Behavioral Ecology and Sociobiology, 2013Co-Authors: Ashley J. W. Ward, Suzanne CurrieAbstract:Animals that form groups are typically assorted by phenotype. For example, fish shoals are notably composed of closely size-matched individuals, yet the Sensory Mechanisms that promote this behaviour have not been fully determined. Here, we show that two freshwater shoaling fish species, three-spined stickleback and banded killifish, have a greater preference for the chemical cues of conspecifics that are the same size as themselves than for those of larger or smaller conspecifics. We suggest that this ability to determine their own size relative to conspecifics may be based on chemical self-referencing. This provides a novel insight to the Mechanisms underlying a widespread phenomenon in social behaviour, and provides further evidence of the crucial role played by chemical cues in structuring the interactions of fishes.
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Mixed-species shoaling in fish: the Sensory Mechanisms and costs of shoal choice
Behavioral Ecology and Sociobiology, 2002Co-Authors: Ashley J. W. Ward, Stephen Axford, Jens KrauseAbstract:The Mechanisms and functions of mixed-species shoaling were investigated in two sympatric species of cyprinids, the chub and the European minnow, from the river Wharfe where they comprised approximately 70% of all year 0+ fish over a 20-year survey. Chub preferred conspecific shoals over heterospecific ones with olfactory cues being more important than visual ones for shoal choice. This preference was consistent with measurements of length:flank area ratios and length:weight ratios which suggest that both species are similar in appearance. When presented with mixed-species shoals, chub increased the percentage time spent with stimulus shoals with increasing proportions of conspecifics. Feeding experiments suggest that the preference for conspecific shoals is driven by interspecific competition (with minnows out-competing similar-sized chub) and the oddity effect. The importance of this work in the context of species assortment in free-ranging shoals is discussed.
