首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   9篇
  完全免费   2篇
  2018年   1篇
  2017年   1篇
  2012年   1篇
  2007年   1篇
  2003年   1篇
  1999年   1篇
  1998年   1篇
  1997年   1篇
  1996年   1篇
  1994年   2篇
排序方式: 共有11条查询结果,搜索用时 78 毫秒
1.
All caterpillars possess a pair of maxillary palps that “drum” the surface of foods during feeding. These chemosensory organs contain over 65% of a caterpillar's taste receptor cells, but their functional significance remains largely unknown. We examined their role in rejection of plant allelochemicals, using the tobacco hornworm (Manduca sexta) as a model insect and an extract from a plant species (Grindeliaglutinosa) as a model stimulus. We selected this system because hornworms reject foods containing Grindelia extract, and because preliminary studies indicated that their maxillary palps respond to this extract. We hypothesized that Grindelia extract elicits rejection through stimulating: (1) olfactory receptor cells, (2) taste receptor cells, (3) oral mechanoreceptors, and/or (4) a postingestive response mechanism. Our results were consistent only with hypothesis 2: caterpillars approached Grindelia-treated diets without apparent hesitation, but rejected it within 6 s of initiating biting; Grindelia-treated solutions stimulated taste receptor cells in the maxillary palp, but not the other gustatory chemosensilla; and ablating the maxillary palps eliminated rejection of Grindelia-treated diets. Our results demonstrate that taste receptor cells in the maxillary palps mediate rejection of Grindelia extract, and provide the first direct evidence for a role of maxillary palps in rejection of plant allelochemicals. Accepted: 25 January 1998  相似文献
2.
The sub-oesophageal ganglion of Locusta migratoria was searched for neurones responsive to stimulation of the maxillary palps using intracellular recording techniques. Two plant stimuli were used: wheat, a host plant and cabbage, an unacceptable non-host plant. The stimuli were presented to the palp as both intact leaf tissue and as droplets of aqueous solutions of plant extracts. All the sampled neurones that responded to stimulation of the palp also responded to simple mechanical stimulation. However, 25% of the neurones exhibited consistent differences in response to the two plants when presented as both leaf tissue and droplets, strongly suggesting that they also received a chemosensory input. These differential responses most commonly took the form of differences in the duration of cell activity and/or variation in the latency of the onset of response. The receptive fields of differentially responding neurones were confined to the maxillary palp, or at most to the maxillary and labial palps.  相似文献
3.
Keil TA 《Tissue & cell》1996,28(6):703-717
The ultrastructure of sensilla on the maxillary palps of helicoverpa armigera caterpillars has been investigated in order ot find candidates for CO(2)-receptors. The following sensilla are found on the palps: a) 8 chemosensory pegs at the tip; b), a large distal pore plate; c), a smaller proximal pore plate; d), a digitiform organ; e), a campaniform sensillum; and f), 3 scolopidia. Each chemosensory peg at the tip is innervated by 4-5 sensory neurons. Five of these pegs are most probably contact chemoreceptors, because each has a dendrite with a tubular body. The distal pore plate has a porous cuticle and is innervated by 3 sensory neurons, each of which sends a highly branched dendrite into a large cuticular cavity. The proximal pore plate is made up from two fused organs, has also a porous cuticle, and is innervated by two sensory neurons which send their dendrites into a narrow cuticular channel. The digitiform organ is innervated by one sensory cell which sends a highly lamellated dendrite into a narrow channel within a chip-shaped protrusion of the porous cuticle. For several reasons, the digitiform organ is the most probable candidate for the CO(2)-receptor. Another possible candidate is the distal pore plate.  相似文献
4.
We describe the kinetics of odorant response in the maxillary palp of Drosophila, and show that the rate of recovery from odorant stimulation is affected by mutation of the rdgB (retinal degeneration B) gene. We use immunocytochemistry to confirm that the rdgB gene product is expressed in the maxillary palp. rdgB has recently been shown to encode a protein with Ca2+-binding sites and sequence similarity to rat brain phosphatidylinositol transfer protein; it is located near the rhabdomeric membranes in photoreceptor cells, where it has been suggested to play a role in membrane transport. The delay in recovery kinetics that we observe in olfactory tissue may reflect a defect in membrane restoration at the conclusion of the olfactory transduction cascade. The use of common molecules in the physiology of two olfactory organs, and in both visual and olfactory physiology, is discussed.Abbreviations EAG electroantennogram - EPG electropalpogram - ERG electroretinogram - norpA no receptor potential A - PBS phosphate buffered saline - rdgB retinal degeneration B - PI phosphatidylinositol  相似文献
5.
Maxillary palps have been proposed as secondary olfactory organs, after the antennae, in Drosophila melanogaster. Our study tries to establish the quantitative importance of both organs as olfactory information mediators. Dose-response curves for three odorants: ethyl acetate, propionaldehyde and benzaldehyde were carried out for comparing olfaction in either complete animals or flies surgically deprived of antennae. Antennaless flies tested in our behavioral assay showed indifferent, attractant and repellent responses depending on concentration, similarly as normal flies do. However, they clearly displayed less sensitivity than normal flies. The range of concentrations they were able to perceive was correlated to antennal sensitivity approximately by a factor 110 for ethyl acetate and benzaldehyde, and between 110 and 1100 at high concentrations of propionaldehyde. A complementary experiment was performed to test changes in olfactory behavior produced by removing maxillary palps in the presence of antennae. At high concentrations of odorant, responses to ethyl acetate and propionaldehyde experienced small changes when both palps were removed. Results are compatible with a summation model of all olfactory information reaching the brain either through antennae or palps.Abbreviations ANOVA analysis of variance - EAG electroantennogram, extracellular recording of electrical changes produced on the antenna in response to odorant stimulation - EPG electropalpogram, extracellular recording of electrical changes produced on the maxillary palp in response to odorant stimulation - IO Olfactory index  相似文献
6.
The tip of the maxillary palp in the spruce budworm and other lepidoptera larvae contains a cluster of eight basiconic sensilla. Except for a few electrophysiological recordings from the entire group of these sensilla, no information is available on the response characteristics of any individual one. Using a compound microscope at 320x magnification, with a long working-distance objective, it has been possible to view individual sensilla and to record electrical responses from three of these to some gustatory stimuli in preliminary tests. One of them, sensillum (L1), contains a sugar-sensitive neuron whose responses to a range of sucrose concentrations are reported here. The physiological characteristics of this neuron differ from those of the known sugar-sensitive neuron in the lateral styloconic sensillum on the galea of these same insects. Input of chemosensory information about the same gustatory stimulus by more than one neuron in different mouthpart sensilla is discussed in relation to the feeding habits of the spruce budworm.  相似文献
7.
The ultrastructure and physiology of the maxillary palp of Drosophila melanogaster have been studied in wild-type and lozenge mutants. Olfactory physiology in the maxillary palp is shown to depend upon the lozenge(lz) gene. Reduced response amplitudes were recorded for all odorants tested, and the physiological defect was shown to map to the lz locus. The structure of the maxillary palp sensilla is described by scanning electron microscopy (SEM) at high magnification, initially in the wild-type. A linear arrangement of pores, connected by furrows, was found in one class of sensilla, the basiconic sensilla. In the lz 3 mutant, morphological alterations in the basiconic sensilla and duplications of sensilla are documented by SEM. The correlation of structural abnormalities in the lz sensilla and physiological abnormalities in odorant response are consistent with an olfactory role for the basiconic sensilla of the maxillary palp. Accepted: 10 September 1996  相似文献
8.
王颖娟  李子忠 《昆虫知识》2012,49(6):1636-1642
利用扫描电镜对锈翅蚁蛉Myrmeleon ferrugineipennis Bao&Wang雌雄成虫头部触角及口器感器的形态进行观察,描述了感器的种类、数量和分布,以期解析其取食机制。结果表明:锈翅蚁蛉触角上存在10种感器,即毛形感器、锥形感器、刺形感器、腔形感器、钟状感器、鳃形感器、耳形感器、盘形感器、舌形感器和Bhm氏鬃毛,其中毛形感器有3种亚型,数量最多;耳形感器、腔形感器和钟状感器仅在雌成虫触角上发现,而舌形感器和鳃形感器仅在雄成虫触角上发现;在锈翅蚁蛉触角鞭节近末端扁平匙状处各有1枚盘形感器,其形状和位置在雌雄虫上有差异。鳃形感器和盘形感器在已有的昆虫感器研究中未见报道,是新发现的昆虫触角感器。下颚须、下唇须上均发现锥形感器,下唇须上的数量多于下颚须;此外,下颚须上还存在钟状感器。  相似文献
9.
The L1 contact-chemoreceptor sensillum on the maxillary palp of the spruce budworm larva Choristoneura fumiferana (Clem.) (Lepidoptera: Tortricidae) was examined electrophysiologically for its responses to stimulation by various pyranose and furanose sugars. The results were compared to those from previous work on the sugar-sensitive neuron of the LST sensillum on the galea. We show that the L1 contact-chemoreceptor sensillum contains one sugar-sensitive neuron with furanose but no pyranose sites. It has response characteristics that differ from those of the sugar-sensitive neuron in the LST. Behavioural 2-choice feeding experiments show that, even with both known sugar-sensitive neurons disabled, larvae can still discriminate between disks treated with either distilled water or alpha-D-glucose. We conclude that the epipharyngeal sensilla must thus also contain a sugar-sensitive neuron.  相似文献
10.
Chlorophorus caragana is a species of long‐horned beetle that damages Caragana davazamcii Sancz. (Fabales: Papilionaceae) bushes in desert areas in China. The beetles cause substantial damage to local forestry plantations and the environment. Sensilla on the maxillary and labial palps of coleopterans a allow the insects to recognize their host plants. We used scanning and transmission electron microscopy to study the ultrastructure, distribution, and abundance of various sensilla on the maxillary and labial palps of C. caragana. We found four types of sensilla including ten subtypes: one of Böhm's bristles, three of sensilla chaetica, one of digitiform sensilla, and five of sensilla twig basiconica. The types and distribution of the sensilla on the maxillary and labial palps were highly similar between males and females. Finally, this article discusses the functions of the sensilla of related species in recognizing hosts and the significance of gustation studies in the context of the control of C. caragana.  相似文献
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号