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21.
Rawson NE Eberwine J Dotson R Jackson J Ulrich P Restrepo D 《Journal of neurochemistry》2000,75(1):185-195
Evidence has accumulated to support a model for odorant detection in which individual olfactory receptor neurons (ORNs) express one of a large family of G protein-coupled receptor proteins that are activated by a small number of closely related volatile chemicals. However, the issue of whether an individual ORN expresses one or multiple types of receptor proteins has yet to be definitively addressed. Physiological data indicate that some individual ORNs can be activated by odorants differing substantially in structure and/or perceived quality, suggesting multiple receptors or one nonspecific receptor per cell. In contrast, molecular biological studies favor a scheme with a single, fairly selective receptor per cell. The present studies directly assessed whether individual rat ORNs can express multiple receptors using single-cell PCR techniques with degenerate primers designed to amplify a wide variety of receptor sequences. We found that whereas only a single OR sequence was obtained from most ORNs examined, one ORN produced two distinct receptor sequences that represented different receptor gene families. Double-label in situ hybridization studies indicated that a subset of ORNs co-express two distinct receptor mRNAs. A laminar segregation analysis of the cell nuclei of ORNs labeled with the two OR mRNA probes showed that for one probe, the histogram of the distribution of the cell nuclei along the depth of the epithelium was bimodal, with one peak overlapping the (unimodal) histogram for the other probe. These results are consistent with co-expression of two OR mRNAs in a population of single ORNs. 相似文献
22.
光周期对雄性布氏田鼠种内个体气味辨别的影响 总被引:1,自引:1,他引:0
本文研究了成年雄性布氏田鼠对不同光照周期下(长光照: LD; 短光照: SD) 的陌生雌鼠和陌生雄鼠气味的行为表现。实验发现: 所有被试雄鼠对LD 雄鼠、雌鼠气味比SD 雄鼠、雌鼠气味有更多的社会探究行为。LD 雄鼠比SD 雄鼠对同性或异性陌生个体气味的嗅闻和挖掘行为要多, 而且差异显著。在探究LD 动情雌鼠气味源时, LD 雄鼠比SD 雄鼠表现出更多的嗅闻和挖掘行为; 在探究SD 动情雌鼠气味源时, LD 和SD 雄鼠的行为反应没有明显差别。所有被试雄鼠在LD 雄鼠气味源箱中的停留时间都显著多于在SD 雄鼠气味源箱中的停留时间。LD 雄鼠在LD 雌鼠气味源箱中的停留时间显著多于在SD 雌鼠气味源箱中的停留时间; 而SD 雄鼠在LD 和SD 雌鼠气味源箱中的进入频次和停留时间没有明显差别。同时, LD 雄鼠对LD 动情雌鼠的气味在嗅闻频次和嗅闻时间上多于非动情LD 雌鼠, 而对SD 动情和非动情雌鼠的气味没有表现出明显的偏好; SD 雄鼠对LD 和SD 动情雌鼠的嗅闻行为仅在频次上显著多于对非动情雌鼠的嗅闻, 而在时间上没有显著差别。结果表明: 布氏田鼠嗅觉通讯中的个体气味及其对气味进行辨别过程中的行为反应都随着光照周期的不同而发生变化。动物的个体气味带有季节性信息, 来源于长光照下的气味比短光照下的气味更具有性吸引; 短光照在一定程度上可能抑制了雌鼠的动情和雄鼠的性行为反应。其嗅觉通讯行为的适应意义可能在于: 减少秋季短日照环境下的繁殖活动, 提高雄性个体之间的社会容忍性以利于集群越冬。 相似文献
23.
In the honeybee Apis mellifera, a sting pheromone produced by sting glands plays an important role in coordinating defensive behavior. This pheromone is a blend constituted by several components. Little is known about the neural substrates underlying sting pheromone processing in the bee brain. Here, we investigated the neural activity elicited by eight components (five acetates and three alcohols) of the sting pheromone, and by real bee stings at the level of the antennal lobe (AL) of worker honeybees. We used in vivo calcium imaging to record odor-induced neural activity of 22 identified glomeruli in the AL. We found that acetates mainly activated medial glomeruli while alcohols mainly activated lateral dorsal glomeruli. The sting preparation evoked a glomerular pattern that was clearly distinct from those of individual pheromone components. No particular region of the imaged AL was found to process sting pheromone or any of its components. Further analyses in a putative honeybee olfactory space showed that the neural activity elicited by sting preparation cannot be linearly predicted by those of pheromone components and that such components are not clearly separated from non-sting pheromone odors. We conclude that sting pheromone is processed in the worker honeybee AL following the same principles of general odors so that the chemical structure of odorants is the main determinant of glomerular activation, rather than their pheromonal values. We cannot exclude, however, that the distinctness of sting-pheromone representation with respect to that of its components constitutes a form of specialized neural processing strategy for this kind of substance. 相似文献
24.
Matthias Laska Åsa Rosandher Sara Hommen 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2008,194(11):971-980
Using an operant conditioning paradigm we tested the ability of CD-1 mice to discriminate between 25 odorants comprising members of five homologous series of aliphatic odorants (C4-C8) presented at a gas phase concentration of 1 ppm. We found (a) that all mice significantly discriminated between all 50 stimulus pairs that involved odorants sharing the same functional group, but differing in carbon chain length, as well as between all 50 stimulus pairs that involved odorants sharing the same carbon chain length but differing in functional group, (b) a significant negative correlation between discrimination performance and structural similarity of odorants in terms of differences in carbon chain length with the acetic esters and the 2-ketones, but not with the 1-alcohols, n-aldehydes, and n-carboxylic acids tested, and (c) that odorant pairs differing in functional group were significantly better discriminated than odorant pairs differing in carbon chain length. These findings demonstrate that CD-1 mice have excellent discrimination ability for structurally related aliphatic odorants, that correlations between discrimination performance and structural similarity of odorants are odorant class-specific rather than a general phenomenon, and that both carbon chain length and type of functional group play an important role for odor quality coding in mice. 相似文献
25.
A pilot-scale mobile biofilter was developed where two types of wood chips (western cedar and 2 in. hardwood) were examined to treat odor emissions from a deep-pit swine finishing facility in central Iowa. The biofilters were operated continuously for 13 weeks at different air flow rates resulting in a variable empty bed residence time (EBRT) from 1.6 to 7.3 s. During this test period, solid-phase microextraction (SPME) PDMS/DVB 65 microm fibers were used to extract volatile organic compounds (VOCs) from both the control plenum and biofilter treatments. Analyses of VOCs were carried out using a multidimentional gas chromatography-mass spectrometry-olfactometry (MDGC-MS-O) system. Results indicated that both types of chips achieved significant reductions in p-cresol, phenol, indole and skatole which represent some of the most odorous and odor-defining compounds known for swine facilities. The results also showed that maintaining proper moisture content is critical to the success of wood-chip based biofilters and that this factor is more important than media depth and residence time. 相似文献
26.
Julia Schuckel Shannon Meisner Päivi H. Torkkeli Andrew S. French 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2008,194(5):483-489
Time-dependent properties of chemical signals are probably crucially important to many animals, but little is known about
the dynamics of chemoreceptors. Behavioral evidence of dynamic sensitivity includes the control of moth flight by pheromone
plume structure, and the ability of some blood-sucking insects to detect varying concentrations of carbon dioxide, possibly
matched to host breathing rates. Measurement of chemoreceptor dynamics has been limited by the technical challenge of producing
controlled, accurate modulation of olfactory and gustatory chemical concentrations over suitably wide ranges of amplitude
and frequency. We used a new servo-controlled laminar flow system, combined with photoionization detection of surrogate tracer
gas, to characterize electroantennograms (EAG) of Drosophila antennae during stimulation with fruit odorants or aggregation pheromone in air. Frequency response functions and coherence
functions measured over a bandwidth of 0–100 Hz were well characterized by first-order low-pass linear filter functions. Filter
time constant varied over almost a tenfold range, and was characteristic for each odorant, indicating that several dynamically
different chemotransduction mechanisms are present. Pheromone response was delayed relative to fruit odors. Amplitude of response,
and consequently signal-to-noise ratio, also varied consistently with different compounds. Accurate dynamic characterization
promises to provide important new information about chemotransduction and odorant-stimulated behavior. 相似文献
27.
By a simple methodology, we have synthesized 68 carboxamides, with structural analogy to the most efficient mosquitoes repellent DEET (N,N-diethyl-m-toluamide, 9). Eight of them have very promising olfactory profiles. In addition, 34 carboxamides have been tested for their repellency properties against three breeds of cockroach; six of them are excellent in this domain. Two of these, the 2-ethyl-N-isopropyl-N-methylbutanamide and N,N-diallyl-2-ethylbutanamide combine both the positive aspects, and are thus very good candidates for use in functional perfumery, and more particularly in home-care formulations. 相似文献
28.
布鲁斯效应是一种由非配偶雄性的化学信号所诱发的雌性妊娠终止现象,曾被认为是雌性对抗雄性杀婴行为的一种进化策略。布鲁斯效应最初在实验小鼠中发现。后续的研究证明了在实验室条件下多种啮齿类动物中存在布鲁斯效应。布鲁斯效应是否为实验室啮齿类动物中存在的普遍规律,目前尚无定论。本实验首先探讨了布鲁斯效应在金色中仓鼠中是否存在。在交配之后给予实验组雌鼠陌生雄鼠的非直接接触刺激,对照组雌鼠接受配偶雄鼠的非直接接触刺激。同时还测定了雌鼠的体重、胚胎质量以及生理器官(肾上腺、脾脏、卵巢和子宫)质量。结果显示,实验组雌鼠的流产率、体重、胚胎质量、生理器官(肾上腺、脾脏、卵巢、子宫)质量与对照组不存在显著差异。本实验结果表明:陌生雄鼠的化学信号对雌性金色中仓鼠的怀孕状态没有影响,实验室条件下的金色中仓鼠不存在布鲁斯效应。 相似文献
29.
Patricia D. Millner 《Bioresource technology》2009,100(22):5379-5385
Air emissions from animal housing and manure management operations include a complex mixture of biological, microbial, and inorganic particulates along with odorous volatile compounds. This report highlights the state of current issues, technical knowledge, and remaining challenges to be addressed in evaluating the impacts of airborne microorganisms, dusts, and odorants on animals and workers at animal production facilities and nearby communities. Reports documenting bioaerosol measurements illustrate some of the technical issues related to sample collection, analysis, as well as dispersion and transport to off-farm locations. Approaches to analysis, mitigation and modeling transport are discussed in the context of the risk reduction and management of airborne spread of bioaerosols from animal operations. The need for standardization and validation of bioaerosol collection and analytical techniques for indoor as well as outdoor animal agriculture settings is critical to evaluation of health effects from modern animal production systems that are increasingly situated near communities. 相似文献
30.