Chemosensory stimuli

Elliot, E. J. (1986). Chemosensory stimuli in feeding behavior of the leech Hirudo medici-nalis. Journal of Comparative Physiology 159,391-401. 

Elliott EJ (1986) Chemosensory stimuli in feeding behavior of the leech Hirudo medicinalis. J Comp Physiol A Neuroethol Sensory Neural Behav Physiol 159 391-401 Kreuter K, Baier B, ABmann C, Steidle JLM (2008) Prey location and prey choice by the freshwater leech Erpobdella octoculata using foraging kairomones. Freshwater Biol 53 1524-1530... 

Sensory systems neuroscience. Academic, San Diego, pp 1-43 Zippel HP, Voigt R, Knaust M, Luan Y (1993) Spontaneous behaviour, training and discrimination training in goldfish using chemosensory stimuli. J Comp Physiol A 172 81-90 Zou Z, Buck LB (2006) Combinatorial effects of odorant mixes in olfactory cortex. Science 311 1477-1481... 

Since stearic acid is a solid that is virtually insoluble in saliva, this lipid is predicted to yield a minimal taste response when compared to long-chain fatty acids that are oils at physiological temperature. Saturated fats such as stearic acid produce insoluble mixtures in water that may cause both a tactile and a chemosensory response. However, hydrophobic chemosensory stimuli can be presented to subjects as complex emulsions of gum acacia, EDTA, water, and mineral oil that mask the viscosity of fatty acid stimuli [2,4,21,22, 77]. These emulsions may trigger a tactile response on the tongue surface, and may show heterogeneity in the distribution and amoimts of fatty acid that are suspended in the emulsion. 

Macrides, F., Clancy, A. N., Singer, A. G. and Agosta, W. C. (1984) Male hamster investigatory and copulatory responses to vaginal discharge an attempt to impart sexual significance to an arbitrary chemosensory stimulus. Physiol. Behav. 33, 627-632. 

Meredith M. (1982). Stimulus access and other processes involved in nasal chemosensory function potential substrates for neuronal and hormonal influence. In Olfaction and Endocrine Regulation (Breipohl W., ed.). IRL Press, London, pp. 223-248. 

A full understanding of chemical ecology must therefore include not only the characterization of chemically unique signals but also their environmental dispersal and degradation patterns that are an intrinsic part of chemosensory transduction and signal processing and lead to the appropriate behavioral responses. One of the most difficult tasks has been to measure the natural stimulus dispersal patterns at a spatial and temporal resolution relevant to the animal. 

The sensitivity and selectivity of olfaction and contact chemosensation are due (1) in the brain, to the existence of a neuronal network of neurons tuned to a specific chemical stimulus, and (2) in the periphery, to the existence of olfactory/ chemosensory receptor neurons housed in sensory microorgans called sensilla. The sensilla can best be viewed as simple cuticular porous extrusions that increase the surface that captures airborne odorants or chemicals dissolved in water droplets. They contain the receptive olfactory or chemosensory structures (Schneider, 1969). The olfactory sensilla are most numerous on the antennae and mediate the reception of sex pheromones and plant volatiles, as well as other odorants. Low volatility pheromones may also be detected by contact chemoreceptors on... 

The ability to discriminate different molecules constitutes a criterion for olfaction. Because, as mentioned, anosmic persons can tell some pairs of odors apart based on nonolfactory cues, an experimenter must choose with care the compounds for study. 3-Phenethyl alcohol has an odor that many people find reminiscent of roses, and vapors from dilute solutions are widely accepted as an olfactory stimulus that does not interact with other chemosensory modalities in humans (Betcher Doty, 1998). Consider a human subject who can detect J3-phenethyl alcohol with the same sensitivity as nor-mosraics and can also detect -butanol (another alcohol often used for testing olfactory sensitivity (Hummel et al., 1997), which has an odor very different from that of P-phenethyl alcohol) with normal acuity. Suppose this subject cannot distinguish the two odors. How can an experimenter assess whether the subject exhibits the sense called olfaction ... 

CO2/H+stimulus Cellular K+current suppression — Cell depolarization Voltage-dependent Ca- gale opens Ca- influx andstore-operated Ca +release [Ca +] rise Neurotransmission Instantaneous chemosensory discharge (acute effects like hypoxia). 

Most of the studies reviewed here rely on tongue-flicking rates to measure the relative intensities of chemosensory investigation elicited by various stimuli. A basic assumption in our interpretation of all such studies is that there is a direct correlation between tongue-flick rate and degree of chemosensory investigation of the stimulus. Differences in... 

The best possible outcome of a bioassay is the elicitation of a specific behavior pattern by a defined chemical stimulus (Miiller-Schwarze 1977). This chapter presents methods to assess the role of chemical stimuli in the behavior of birds and mammals. An overview of the chemosensory capacities of birds and mammals to perceive stimuli is provided first, followed by a description of test paradigms that can be incorporated into bioassays. The preponderance of the chapter describes examples of these paradigms incorporated into bioassays to assess the role of chemical signals in inter- and intra-specific behaviors. The examples, like past studies in mammalian and avian chemical ecology, are disproportionately represented by rodents. Most of the described procedures, however, could be modified for other species, provided the apparatuses and the response variables can be altered to accommodate the different subject and stimuli. 

Food preferences also can be learned, and, like learned aversions, conditioned preferences can be used to evaluate chemosensory abilities. Typically, preferences are induced by pairing the ingestion of a novel flavor with calories (Bolles et al. 1981 Messier White 1984 Booth 1985 Mehiel Bolles 1984, 1988 Simbayi et al. 1985), recovery from nutritional deficiency (Garcia et al. 1967 Zahorik et al. 1974), and recovery from malaise (Green Garcia 1971 Zahorik 1977 Sherman et al. 1983). The novel flavor is subsequently preferred, as are other flavors that subjects perceive as similar to the conditioned stimulus. However,... 

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