High Intensity Light Increases Olfactory Bulb Melatonin in Venezuelan Equine Encephalitis Virus Infection

In mice infected with the Venezuelan equine encephalomyelitis (VEE) virus and exposed to high intensity light (2500 lux) with a 12 h light: 12 h dark photoperiod, a significant increase in the levels of melatonin in the olfactory bulb was observed. The significance of these findings deserves further studies to understand the mechanisms involved in this effect since the olfactory bulbs have been proposed as first portal for VEE virus entry into the CNS. The increase in melatonin content could represent one of the mechanisms of defense against the viral attack.     

Molecular biology of insect olfaction:recent progress and conceptual models

Insects have an enormous impact on global public health as disease vectors and as agricultural enablers as well as pests and olfaction is an important sensory input to their behavior. As such it is of great value to understand the interplay of the molecular components of the olfactory system which, in addition to fostering a better understanding of insect neurobiology, may ultimately aid in devising novel intervention strategies to reduce disease transmission or crop damage. Since the first discovery of odorant receptors in vertebrates over a decade ago, much of our view on how the insect olfactory system might work has been derived from observations made in vertebrates and other invertebrates, such as lobsters or nematodes. Together with the advantages of a wide range of genetic tools, the identification of the first insect odorant receptors in Drosophila melanogaster in 1999 paved the way for rapid progress in unraveling the question of how olfactory signal transduction and processing occurs in the fruitfly. This review intends to summarize much of this progress and to point out some areas where advances can be expected in the near future.     

Hypertrophic smooth muscle

The neurones from the wind-sensitive hairs on the locust head have been filled with cobalt chloride and intensified with silver. All the neurones project through the brain to the suboesophageal ganglion, some continue to the prothoracic ganglion and a few as far as the mesothoracic ganglion. Three different types of projection are described and a regrouping is proposed of Weis-Fogh's five hair fields into three areas. The distribution of the neurones from these areas is described in relation to other structures in the ganglion and is discussed in relation to the function of the hair fields in stability control and grooming.     

钾对兰州百合鳞茎中多酚类物质积累代谢及其抗氧化活性的影响

为探究施钾对兰州百合鳞茎中多酚类物质的积累、抗氧化能力及差异代谢物的影响,该研究以兰州百合鳞茎为试材,通过固定氮素(N)和磷素(P)用量,设置不同钾(K)浓度处理,即K_(0)(不施肥)、K_(1)(447.6 mg·L^(-1))、K_(2)(671.4 mg·L^(-1))、K_(3)(895.2 mg·L^(-1)),采用福林-肖卡法、溴甲酚绿比色法、香草醛比色法、DPPH法、铜离子还原能力(CUPRAC)法测定不同K浓度处理下兰州百合鳞茎中多酚类物质含量及其抗氧化活性,并采用LC-MS法分析多酚类物质的差异代谢物,并进行差异代谢物筛选,功能注释及富集分析,为兰州百合的优质栽培提供理论依据。结果表明:(1)不同K浓度处理下兰州百合鳞茎中多酚类物质的含量及其抗氧化活性存在显著差异(P<0.05),与K_(0)相比,K_(1)、K_(2)、K_(3)均能促进鳞茎多酚类物质的积累及其抗氧化能力的提高,其中以K_(2)(671.4 mg·L^(-1))效果最佳。(2)相关性分析表明,兰州百合鳞茎多酚类物质含量与抗氧化活性指标呈极显著(P<0.01)相关关系,相关系数为0.451~0.959。(3)K_(0)、K_(2)浓度处理下兰州百合鳞茎中存在89种多酚类及相关化合物,其中52种相对含量显著上调,37种相对含量显著下调,且显著富集到黄酮类及苯丙类化合物生物合成的通路上。研究认为,兰州百合的最佳施钾量(671.4 mg·L^(-1))能有效促进鳞茎中多酚类物质的积累并提高其抗氧化能力。     

Application of an induced field sensor for assessment of electromagnetic exposure from compact fluorescent lamps

The development of scientifically sound instrumentation, methods, and procedures for the electromagnetic exposure assessment of compact fluorescent lamps (CFLs) is investigated. The incident and induced fields from 11 CFLs have been measured in the 10 kHz–1 MHz range, and they are compared with the levels for incandescent and light emitting diode (LED) bulbs. Commercially available equipment was used to measure the incident fields, while a novel sensor was built to assess the induced fields in humans. Incident electric field levels significantly exceed the International Commission on Non‐Ionizing Radiation Protection (ICNIRP) reference levels at close distances for some sources, while the induced fields are within the ICNIRP basic restrictions. This demonstrates the importance of assessing the induced fields rather than the incident fields for these sources. Maximum current densities for CFLs are comparable to the limits (in the range of 9% to 56%), demonstrating the need for measurements to establish compliance. For the frequency range investigated, the induced fields were found to be considerably higher for CFLs than for incandescent light bulbs, while the exposure from the two LED bulbs was low. The proposed instrumentation and methods offer several advantages over an existing measurement standard, and the measurement uncertainty is significantly better than the assessment of electric and magnetic fields at close distances. Bioelectromagnetics 33:166–175, 2012. © 2011 Wiley Periodicals, Inc.     

Fine structure of a sensory organ in the arista of Drosophila melanogaster and some other dipterans

Summary The arista, a characteristic appendage of dipteran antennae, consists of 2 short segments at the base and a long distal shaft. A small sensory ganglion, from which arises the aristal nerve, is located proximally in the shaft. The fine structure of the aristal sensory organ was studied in detail in the fruitfly (Drosophila) and for comparison in the housefly (Musca) and the blowfly (Calliphora). In Drosophila, the aristal sense organ consists of 3 identical sensilla that terminate in the hemolymph space of the aristal shaft, and not in an external cuticular apparatus. Each sensillum comprises 2 bipolar neurons and 2 sheath cells; a third sheath cell envelops the somata of all six neurons of the ganglion. The neurons have long slender dendrites with the usual subdivision into an inner and an outer segment. One of the outer segments is highly lamellated and bears small particles (BOSS-structures) on the outside of its cell membrane; the other outer segment is unbranched and has a small diameter. The fine structure of the first dendrite is strongly reminiscent of thermoreceptors known from the antennae of other insects. These thermoreceptors are often coupled with hygroreceptors; however, we can only speculate whether the second dendrite of the aristal organ also has this function. Our present results argue against mechanoreceptive functions, as formerly postulated. The aristal sense organs in Musca and Calliphora are similar to those in Drosophila, but contain more sensilla (12 in Musca, 18 in Calliphora).     

Distribution of sensory neurones of the pudendal nerve in the dorsal root ganglia and their projection to the spinal cord

Summary The morphology and distribution of the sensory neurones of the pudendal nerve within the spinal ganglia of rats were investigated by use of horseradish peroxidase (HRP). The labelling was visualized in diaminobenzidine (DAB) or tetramethyl-benzidine (TMB)-stained sections. Injection of HRP directly into the pudendal nerve labelled perikarya predominantly in the sixth lumbar DRG (L6). Following injection of HRP into the scrotal skin, however, additional cells were labelled in L5 and SI. Labelling was invariably unilateral. Approximately equal numbers of small (<30 m) and large neurones (>40 m) were labelled following subcutaneous injections although injections into the nerve marked twice as many small cells as large cells. This suggests that, in the rat, most of the small-diameter fibres within the pudendal nerve ascend through L6. Although a cluster of neurones was observed in one experiment, the remaining 25 experiments did not reveal any somatotopic arrangement since the labelled perikarya were distributed evenly throughout the ganglion. Similar numbers of retrogradely labelled neurones (somatopetal transport of the tracer) were observed in both DAB- and TMB-stained sections, although TMB allowed the demonstration of anterograde (somatofugal) HRP transport by terminal labelling in the superficial laminae of the lumbar spinal cord, extending into laminae II–IV.Partially supported by grants from the DFG to HWK (Ko 758/1)     

Evolution of gustatory sensitivity in Yponomeuta caterpillars: sensitivity to the stereo-isomers dulcitol and sorbitol is localised in a single sensory cell

The cellular localisation of the sensitivity to two host-plant specific larval phagostimulants was determined in Yponomeuta evonymellus and in inter-specific hybrids of Y. cagnagellus and Y. padellus. The combined results of cross-adaptation experiments, analysis of mixture responses and inter-spike interval distributions indicated that the sensitivity for sorbitol and dulcitol is localised in the same cell in the investigated species. This result suggests that during the evolution of the genus the main alteration in the mechanism of sugar-alcohol detection occurred at the level of the receptor proteins. Relatively simple modification of this kind can, however, have large effects, since larvae with modified receptor proteins will directly respond to the new stimulus while all central processing and resulting behaviour can remain unmodified. Accepted: 7 October 1998     

Cyclic AMP-Dependent Protein Phosphorylation in Chemosensory Neurons: Identification of Cyclic Nucleotide-Regulated Phosphoproteins in Olfactory Cilia

Chemosensory dendritic membranes (olfactory cilia) contain protein kinase activity that is stimulated by cyclic AMP and more efficiently by the nonhydrolyzable GTP analog guanosine-5'-O-(3-thio)triphosphate (GTP gamma S). In control nonsensory (respiratory) cilia, the cyclic AMP-dependent protein kinase is practically GTP gamma S-insensitive. GTP gamma S activation of the olfactory enzyme appears to be mediated by a stimulatory GTP-binding protein (G-protein) and adenylate cyclase previously shown to be enriched in the sensory membranes. Protein kinase C activity cannot be detected in the chemosensory cilia preparation under the conditions tested. Incubation of olfactory cilia with [gamma-32P]ATP leads to the incorporation of [32P]phosphate into many polypeptides, four of which undergo covalent modification in a cyclic nucleotide-dependent manner. The phosphorylation of one polypeptide, pp24, is strongly and specifically enhanced by cyclic AMP at concentrations lower than 1 microM. This phosphoprotein is not present in respiratory cilia, but is seen also in membranes prepared from olfactory neuroepithelium after cilia removal. Cyclic AMP-dependent protein kinase and phosphoprotein pp24 may be candidate components of the molecular machinery that transduces odor signals.     

Study of changes in physicochemical and microbiological characteristics of shrimps (Melicertus kerathurus) stored under modified atmosphere packaging

Fresh minimally processed shrimps were stored under modified atmosphere packaging (60% CO₂:40% N₂ for MAP A and 92.9% N₂:5.1% CO₂:2% O₂ for MAP B) for 5 days at 3 °C. Total mesophiles, H₂S forming bacteria, Pseudomonas spp., Brochothrix thermosphacta, firmness, color and sensory parameters were investigated throughout the whole time of the experiment. During storage period samples stored under MAP B managed to retain firmness values close to the initial values. All microbial populations growth was suppressed by the presence of MAP A. Samples stored under MAP B managed to maintain their firmness values close to the initial ones while MAP A samples were significantly less firm (p < 0.05).