Change search
Refine search result
1 - 27 of 27
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1. Bisch-Knaden, Sonja
    et al.
    Carlsson, Mikael A.
    Stockholm University, Faculty of Science, Department of Zoology.
    Sugimoto, Yuki
    Schubert, Marco
    Missbach, Christine
    Sachse, Silke
    Hansson, Bill S.
    Olfactory coding in five moth species from two families2012In: Journal of Experimental Biology, ISSN 0022-0949, E-ISSN 1477-9145, Vol. 215, no 9, p. 1542-1551Article in journal (Refereed)
    Abstract [en]

    The aim of the present study was to determine what impact phylogeny and life history might have on the coding of odours in the brain. Using three species of hawk moths (Sphingidae) and two species of owlet moths (Noctuidae), we visualized neural activity patterns in the antennal lobe, the first olfactory neuropil in insects, evoked by a set of ecologically relevant plant volatiles. Our results suggest that even between the two phylogenetically distant moth families, basic olfactory coding features are similar. But we also found different coding strategies in the moths' antennal lobe; namely, more specific patterns for chemically similar odorants in the two noctuid species than in the three sphingid species tested. This difference demonstrates the impact of the phylogenetic distance between species from different families despite some parallel life history traits found in both families. Furthermore, pronounced differences in larval and adult diet among the sphingids did not translate into differences in the olfactory code; instead, the three species had almost identical coding patterns.

  • 2.
    Carlsson, Mikael A.
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Bisch-Knaden, Sonja
    Schäpers, Alexander
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Mozuraitis, Raimondas
    Hansson, Bill S.
    Janz, Niklas
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Odour Maps in the Brain of Butterflies with Divergent Host-Plant Preferences2011In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 6, no 8, article id e24025Article in journal (Refereed)
    Abstract [en]

    Butterflies are believed to use mainly visual cues when searching for food and oviposition sites despite that their olfactory system is morphologically similar to their nocturnal relatives, the moths. The olfactory ability in butterflies has, however, not been thoroughly investigated. Therefore, we performed the first study of odour representation in the primary olfactory centre, the antennal lobes, of butterflies. Host plant range is highly variable within the butterfly family Nymphalidae, with extreme specialists and wide generalists found even among closely related species. Here we measured odour evoked Ca2+ activity in the antennal lobes of two nymphalid species with diverging host plant preferences, the specialist Aglais urticae and the generalist Polygonia c-album. The butterflies responded with stimulus-specific combinations of activated glomeruli to single plant-related compounds and to extracts of host and non-host plants. In general, responses were similar between the species. However, the specialist A. urticae responded more specifically to its preferred host plant, stinging nettle, than P. c-album. In addition, we found a species-specific difference both in correlation between responses to two common green leaf volatiles and the sensitivity to these compounds. Our results indicate that these butterflies have the ability to detect and to discriminate between different plant-related odorants.

  • 3.
    Carlsson, Mikael A.
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Functional Morphology.
    Diesner, Max
    Philipps University, Marburg.
    Schachtner, Joachim
    Philipps University, Marburg.
    Nässel, Dick R.
    Stockholm University, Faculty of Science, Department of Zoology, Functional Morphology.
    Multiple neuropeptides in the Drosophila antennal lobe suggest complex modulatory circuits2010In: Journal of Comparative Neurology, ISSN 0021-9967, E-ISSN 1096-9861, Vol. 518, no 16, p. 3359-3380Article in journal (Refereed)
    Abstract [en]

    The fruitfly, Drosophila, is dependent on its olfactory sense in food search and reproduction. Processing of odorant information takes place in the antennal lobes, the primary olfactory center in the insect brain. Besides classical neurotransmitters, earlier studies have indicated the presence of a few neuropeptides in the olfactory system. In the present study we made an extensive analysis of the expression of neuropeptides in the Drosophila antennal lobes by direct profiling using matrix-assisted laser desorption/ionization-time-of-flight (MALDI-TOF) mass spectrometry and immunocytochemistry. Neuropeptides from seven different precursor genes were unambiguously identified and their localization in neurons was subsequently revealed by immunocytochemistry. These were short neuropeptide F, tachykinin related peptide, allatostatin A, myoinhibitory peptide, SIFamide, IPNamide, and myosuppressin. The neuropeptides were expressed in subsets of olfactory sensory cells and different populations of local interneurons and extrinsic (centrifugal) neurons. In some neuron types neuropeptides were colocalized with classical neurotransmitters. Our findings suggest a huge complexity in peptidergic signaling in different circuits of the antennal lobe.

  • 4.
    Carlsson, Mikael A.
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Enell, Lina E.
    Stockholm University, Faculty of Science, Department of Zoology.
    Nässel, Dick R.
    Stockholm University, Faculty of Science, Department of Zoology.
    Distribution of short neuropeptide F and its receptor in neuronal circuits related to feeding in larval Drosophila2013In: Cell and Tissue Research, ISSN 0302-766X, E-ISSN 1432-0878, Vol. 353, no 3, p. 511-523Article in journal (Refereed)
    Abstract [en]

    Four forms of short neuropeptide F (sNPF1-4), derived from the gene snpf, have been identified in Drosophila and are known to act on a single G-protein-coupled receptor (sNPFR). Several functions have been suggested for sNPFs in Drosophila, including the regulation of feeding and growth in larvae, the control of insulin signalling and the modulation of neuronal circuits in adult flies. Furthermore, sNPF has been shown to act as a nutritional state-dependent neuromodulator in the olfactory system. The role of sNPF in the larval nervous system is less well known. To analyse sites of action of sNPF in the larva, we mapped the distribution of sNPF- and sNPFR-expressing neurons. In particular, we studied circuits associated with chemosensory inputs and systems involved in the regulation of feeding, including neurosecretory cell systems and the hypocerebral ganglion. We employed a combination of immunocytochemistry and enhancer trap and promoter Gal4 lines to drive green fluorescent protein. We found a good match between the distribution of the receptor and its ligand. However, several differences between the larval and adult systems were observed. Thus, neither sNPF nor its receptor was found in the olfactory (or other sensory) systems in the larva and cells producing insulin-like peptides did not co-express sNPFR, as opposed to results from adults. Moreover, sNPF was expressed in a subpopulation of Hugin cells (second-order gustatory neurons) only in adult flies. We propose that the differences in sNPF signalling between the developmental stages is explained by differences in their feeding behaviour.

  • 5.
    Carlsson, Mikael A.
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Schäpers, Alexander
    Stockholm University, Faculty of Science, Department of Zoology.
    Nässel, Dick R.
    Stockholm University, Faculty of Science, Department of Zoology.
    Janz, Niklas
    Stockholm University, Faculty of Science, Department of Zoology.
    Organization of the olfactory system of Nymphalidae butterflies2013In: Chemical Senses, ISSN 0379-864X, E-ISSN 1464-3553, Vol. 38, no 4, p. 355-367Article in journal (Refereed)
    Abstract [en]

    Olfaction is in many species the most important sense, essential for food search, mate finding, and predator avoidance. Butterflies have been considered a microsmatic group of insects that mainly rely on vision due to their diurnal lifestyle. However, an emerging number of studies indicate that butterflies indeed use the sense of smell for locating food and oviposition sites. To unravel the neural substrates for olfaction, we performed an anatomical study of 2 related butterfly species that differ in food and host plant preference. We found many of the anatomical structures and pathways, as well as distribution of neuroactive substances, to resemble that of their nocturnal relatives among the Lepidoptera. The 2 species differed in the number of one type of olfactory sensilla, thus indicating a difference in sensitivity to certain compounds. Otherwise no differences could be observed. Our findings suggest that the olfactory system in Lepidoptera is well conserved despite the long evolutionary time since butterflies and moths diverged from a common ancestor.

  • 6.
    Carlsson, Mikael A.
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Swedberg, Michael D. B.
    A behavioural operant discrimination model for assessment and pharmacological manipulation of visual function in rats2010In: Brain Research, ISSN 0006-8993, E-ISSN 1872-6240, Vol. 1321, p. 78-87Article in journal (Refereed)
    Abstract [en]

    A large number of commercially available drugs are known to cause visual side effects in humans. Therefore, it would be advantageous to screen for alterations in visual function at a pre-clinical stage. Available methods, however, lack control for motivational and motoric side effects. The aim of the present study was therefore to develop a behavioural test to detect and quantify drug-induced visual side effects while simultaneously controlling for other side effects. We here present a novel model based on operant conditioning methodology with a food rewarded two-choice design to assess visual acuity and contrast sensitivity in rats. Rats were trained to discriminate between computer-generated sine-wave gratings and homogenous grey stimuli of equal luminance. They were subsequently tested with novel stimuli differing to training stimuli according to either spatial frequency or contrast. Finally, we tested how visual acuity was affected by oral administration of quinine HCl, a compound known to affect visual function in man. The rats learned to discriminate visual stimuli within 4-5 weeks of twice daily training. A training procedure with moving stimuli achieved faster learning than with static stimuli. The visual detection threshold for discrimination of grating patterns decreased as a function of the contrast level, ranging from a spatial frequency of 0.8 cycles/degree (c/d) at 100% contrast to 0.2 c/d at 12.5%. Administration of quinine HCl was shown to affect the visual acuity threshold in a dose- and time dependent manner. In addition, response rate was affected by quinine administration but temporally isolated from the attenuation of visual acuity demonstrating that this model can separate the visual effects from motoric and motivational side effects.

  • 7. Cunningham, Paul J.
    et al.
    Carlsson, Mikael A.
    Stockholm University, Faculty of Science, Department of Zoology.
    Villa, Thomas F.
    Dekker, Teun
    Clarke, Anthony R.
    Do Fruit Ripening Volatiles Enable Resource Specialism in Polyphagous Fruit Flies?2016In: Journal of Chemical Ecology, ISSN 0098-0331, E-ISSN 1573-1561, Vol. 42, no 9, p. 931-940Article in journal (Refereed)
    Abstract [en]

    Frugivorous tephritid fruit flies have lineages with high levels of host generalism. These insects use olfaction to locate fruits, but how they are able to recognize the odors of so many different host species is poorly understood. We used a series of behavioral experiments to investigate the role of fruit ripening volatiles as host cues in the Queensland fruit fly, Bactrocera tryoni (Froggatt), a polyphagous pest in Australia. Odors of mature guava (Psidium guajava) attracted female and male flies more strongly than three other ripening stages and guava pulp. We analyzed volatiles from guava odor and selected eleven compounds, all of which elicited an electrophysiological response in the antenna of female flies. Three of these, ethyl acetate, ethyl butyrate, and ethyl propionate, were released at the highest rates from the most attractive ripening stage. In behavioral trials, these three esters were not attractive individually, whereas a combination was necessary and sufficient in attracting female flies. The three-component blend was as attractive as the entire 11-component blend, which without these key volatiles was not attractive. Moreover, injecting low ranking hosts (squash and cucumber) with the three volatiles increased attraction in ovipositing female flies. These fruit flies are classed as generalists, but like many polyphagous insects they could be regarded as resource specialists, preferring specific plant reproductive stages with predictable odor cues. Exploring olfaction from this perspective could improve our understanding of host choice in polyphagous insects, and the selection of volatiles to be used as attractants in insect pest management.

  • 8.
    Enell, Lina
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Carlsson, Mikael
    Stockholm University, Faculty of Science, Department of Zoology.
    Aumann, Dominic
    Nässel, Dick
    Stockholm University, Faculty of Science, Department of Zoology.
    Distribution of short neuropeptide F and its receptorin the chemosensory and neuroendocrine systemsof larval DrosophilaManuscript (preprint) (Other academic)
  • 9.
    Eriksson, Maertha
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Functional Morphology.
    Nylin, Sören
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Carlsson, Mikael A.
    Stockholm University, Faculty of Science, Department of Zoology, Functional Morphology.
    Insect brain plasticity: effects of olfactory input on neuropil size2019In: Royal Society Open Science, E-ISSN 2054-5703, Vol. 6, no 8, article id 190875Article in journal (Refereed)
    Abstract [en]

    Insect brains are known to express a high degree of experience-dependent structural plasticity. One brain structure in particular, the mushroom body (MB), has been attended to in numerous studies as it is implicated in complex cognitive processes such as olfactory learning and memory. It is, however, poorly understood to what extent sensory input per se affects the plasticity of the mushroom bodies. By performing unilateral blocking of olfactory input on immobilized butterflies, we were able to measure the effect of passive sensory input on the volumes of antennal lobes (ALs) and MB calyces. We showed that the primary and secondary olfactory neuropils respond in different ways to olfactory input. ALs show absolute experience-dependency and increase in volume only if receiving direct olfactory input from ipsilateral antennae, while MB calyx volumes were unaffected by the treatment and instead show absolute age-dependency in this regard. We therefore propose that cognitive processes related to behavioural expressions are needed in order for the calyx to show experience-dependent volumetric expansions. Our results indicate that such experience-dependent volumetric expansions of calyces observed in other studies may have been caused by cognitive processes rather than by sensory input, bringing some causative clarity to a complex neural phenomenon.

  • 10. Hentze, Julie L.
    et al.
    Carlsson, Mikael A.
    Stockholm University, Faculty of Science, Department of Zoology.
    Kondo, Shu
    Nässel, Dick R.
    Stockholm University, Faculty of Science, Department of Zoology.
    Rewitz, Kim F.
    The Neuropeptide Allatostatin A Regulates Metabolism and Feeding Decisions in Drosophila2015In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 5, article id 11680Article in journal (Refereed)
    Abstract [en]

    Coordinating metabolism and feeding is important to avoid obesity and metabolic diseases, yet the underlying mechanisms, balancing nutrient intake and metabolic expenditure, are poorly understood. Several mechanisms controlling these processes are conserved in Drosophila, where homeostasis and energy mobilization are regulated by the glucagon-related adipokinetic hormone (AKH) and the Drosophila insulin-like peptides (DILPs). Here, we provide evidence that the Drosophila neuropeptide Allatostatin A (AstA) regulates AKH and DILP signaling. The AstA receptor gene, Dar-2, is expressed in both the insulin and AKH producing cells. Silencing of Dar-2 in these cells results in changes in gene expression and physiology associated with reduced DILP and AKH signaling and animals lacking AstA accumulate high lipid levels. This suggests that AstA is regulating the balance between DILP and AKH, believed to be important for the maintenance of nutrient homeostasis in response to changing ratios of dietary sugar and protein. Furthermore, AstA and Dar-2 are regulated differentially by dietary carbohydrates and protein and AstA-neuronal activity modulates feeding choices between these types of nutrients. Our results suggest that AstA is involved in assigning value to these nutrients to coordinate metabolic and feeding decisions, responses that are important to balance food intake according to metabolic needs.

  • 11.
    Kahsai, Lily
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Carlsson, Mikael A.
    Stockholm University, Faculty of Science, Department of Zoology.
    Winther, Åsa M.
    Stockholm University, Faculty of Science, Department of Zoology.
    Nässel, Dick R.
    Stockholm University, Faculty of Science, Department of Zoology.
    Distribution of metabotropic receptors of serotonin, dopamine, GABA, glutamate, and short neuropeptide F in the central complex of Drosophila2012In: Neuroscience, ISSN 0306-4522, E-ISSN 1873-7544, Vol. 208, p. 11-26Article in journal (Refereed)
    Abstract [en]

    The central complex is a prominent set of midline neuropils in the insect brain, known to be a higher locomotor control center that integrates visual inputs and modulates motor outputs. It is composed of four major neuropil structures, the ellipsoid body (EB), fan-shaped body (FB), noduli (NO), and protocerebral bridge (PB). In Drosophila different types of central complex neurons have been shown to express multiple neuropeptides and neurotransmitters; however, the distribution of corresponding receptors is not known. Here, we have mapped metabotropic, G-protein–coupled receptors (GPCRs) of several neurotransmitters to neurons of the central complex. By combining immunocytochemistry with GAL4 driven green fluorescent protein, we examined the distribution patterns of six different GPCRs: two serotonin receptor subtypes (5-HT1B and 5-HT7), a dopamine receptor (DopR), the metabotropic GABAB receptor (GABABR), the metabotropic glutamate receptor (DmGluRA) and a short neuropeptide F receptor (sNPFR1). Five of the six GPCRs were mapped to different neurons in the EB (sNPFR1 was not seen). Different layers of the FB express DopR, GABABR, DmGluRA, and sNPFR1, whereas only GABABR and DmGluRA were localized to the PB. Finally, strong expression of DopR and DmGluRA was detected in the NO. In most cases the distribution patterns of the GPCRs matched the expression of markers for their respective ligands. In some nonmatching regions it is likely that other types of dopamine and serotonin receptors or ionotropic GABA and glutamate receptors are expressed. Our data suggest that chemical signaling and signal modulation are diverse and highly complex in the different compartments and circuits of the Drosophila central complex. The information provided here, on receptor distribution, will be very useful for future analysis of functional circuits in the central complex, based on targeted interference with receptor expression.

  • 12.
    Larsdotter-Mellström, Helena
    et al.
    Stockholm University, Faculty of Science, Department of Zoology. University of Western Australia, Australia.
    Eriksson, Kerstin
    Stockholm University, Faculty of Science, Department of Zoology.
    Janz, Niklas
    Stockholm University, Faculty of Science, Department of Zoology.
    Nylin, Sören
    Stockholm University, Faculty of Science, Department of Zoology.
    Carlsson, Mikael A.
    Stockholm University, Faculty of Science, Department of Zoology.
    Male butterflies use an anti-aphrodisiac pheromone to tailor ejaculates2016In: Functional Ecology, ISSN 0269-8463, E-ISSN 1365-2435, Vol. 30, no 2, p. 255-261Article in journal (Refereed)
    Abstract [en]

    When females mate with multiple partners, the risk of sperm competition depends on female mating history. To maximize fitness, males should adjust their mating investment according to this risk. In polyandrous butterflies, males transfer a large, nutritious ejaculate at mating. Larger ejaculates delay female remating and confer an advantage in sperm competition. We test whether male ejaculate size in the butterfly Pieris napi (Lepidoptera) varies with female mating history and thus sperm competition, and whether males assess sperm competition using the male-transferred anti-aphrodisiac methyl salicylate (MeS) as a cue. Both sexes responded physiologically to MeS in a dose-dependent manner. Males, however, were more sensitive to MeS than females. Ejaculates transferred by males mating with previously mated females were on average 26% larger than ejaculates transferred by males mating with virgin females, which conforms to sperm competition theory and indicates that males tailored their reproductive investment in response to sperm competition. Furthermore, ejaculates transferred by males mating with virgin females with artificially added MeS were also 26% larger than ejaculates transferred to control virgin females. Male-transferred anti-aphrodisiac pheromone not only functions as a male deterrent, but also carries information on female mating history and thus allows males to assess sperm competition.

  • 13.
    Larsdotter-Mellström, Helena
    et al.
    Stockholm University, Faculty of Science, Department of Zoology. The University of Western Australia, Australia.
    Eriksson, Kerstin
    Liblikas, Ilme
    Wiklund, Christer
    Stockholm University, Faculty of Science, Department of Zoology.
    Borg-Karlsson, Anna K.
    Nylin, Sören
    Stockholm University, Faculty of Science, Department of Zoology.
    Janz, Niklas
    Stockholm University, Faculty of Science, Department of Zoology.
    Carlsson, Mikael A.
    Stockholm University, Faculty of Science, Department of Zoology.
    It's All in the Mix: Blend-Specific Behavioral Response to a Sexual Pheromone in a Butterfly2016In: Frontiers in Physiology, ISSN 1664-042X, E-ISSN 1664-042X, Vol. 7, article id 68Article in journal (Refereed)
    Abstract [en]

    Among insects, sexual pheromones are typically mixtures of two to several components, all of which are generally required to elicit a behavioural response. Here we show for the first time that a complete blend of sexual pheromone components is needed to elicit a response also in a butterfly. Males of the Green-veined White, Pieris napi, emit an aphrodisiac pheromone, citral, from wing glands. This pheromone is requisite for females to accept mating with a courting male. Citral is a mixture of the two geometric isomers geranial (E-isomer) and neral (Z-isomer) in an approximate 1:1 ratio. We found that both these compounds are required to elicit acceptance behaviour, which indicates synergistic interaction between processing of the isomers. Using functional Ca2+ imaging we found that geranial and neral evoke significantly different but overlapping glomerular activity patterns in the antennal lobe, which suggests receptors with different affinity for the two isomers. However, these glomeruli were intermingled with glomeruli responding to ,for example, plant-related compounds, i.e. no distinct subpopulation of pheromone-responding glomeruli as in moths and other insects. In addition, these glomeruli showed lower specificity than pheromone-activated glomeruli in moths. We could, however, not detect any mixture interactions among four identified glomeruli, indicating that the synergistic effect may be generated at a higher processing level. Furthermore, correlations between glomerular activity patterns evoked by the single isomers and the blend did not change over time.

  • 14. Lebreton, Sébastien
    et al.
    Carlsson, Mikael A.
    Stockholm University, Faculty of Science, Department of Zoology, Functional Morphology.
    Witzgall, Peter
    Insulin Signaling in the Peripheral and Central Nervous System Regulates Female Sexual Receptivity during Starvation in Drosophila2017In: Frontiers in Physiology, ISSN 1664-042X, E-ISSN 1664-042X, Vol. 8, p. 1-9, article id 685Article in journal (Refereed)
    Abstract [en]

    Many animals adjust their reproductive behaviour according to nutritional state and food availability. Drosophila females for instance decrease their sexual receptivity following starvation. Insulin signalling, which regulates many aspects of insect physiology and behaviour, also affects reproduction in females. We show that insulin signalling is involved in the starvation-induced reduction in female receptivity. More specifically, females mutant for the insulin-like peptide 5 (dilp5) were less affected by starvation compared to the other dilp mutants and wild-type flies. Knocking-down the insulin receptor, either in all fruitless-positive neurons or a subset of these neurons dedicated to the perception of a male aphrodisiac pheromone, decreased the effect of starvation on female receptivity. Disrupting insulin signalling in some parts of the brain, including the mushroom bodies even abolished the effect of starvation. In addition, we identified fruitless-positive neurons in the dorso-lateral protocerebrum and in the mushroom bodies co-expressing the insulin receptor. Together, our results suggest that the interaction of insulin peptides determines the tuning of female sexual behaviour, either by acting on pheromone perception or directly in the central nervous system.

  • 15. Lebreton, Sébastien
    et al.
    Trona, Federica
    Borrero-Echeverry, Felipe
    Bilz, Florian
    Grabe, Veit
    Becher, Paul G.
    Carlsson, Mikael A.
    Stockholm University, Faculty of Science, Department of Zoology.
    Nässel, Dick R.
    Stockholm University, Faculty of Science, Department of Zoology.
    Hansson, Bill S.
    Sachse, Silke
    Witzgall, Peter
    Feeding regulates sex pheromone attraction and courtship in Drosophila females2015In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 5, article id 13132Article in journal (Refereed)
    Abstract [en]

    In Drosophila melanogaster, gender-specific behavioural responses to the male-produced sex pheromone cis-vaccenyl acetate (cVA) rely on sexually dimorphic, third-order neural circuits. We show that nutritional state in female flies modulates cVA perception in first-order olfactory neurons. Starvation increases, and feeding reduces attraction to food odour, in both sexes. Adding cVA to food odour, however, maintains attraction in fed females, while it has no effect in males. Upregulation of sensitivity and behavioural responsiveness to cVA in fed females is paralleled by a strong increase in receptivity to male courtship. Functional imaging of the antennal lobe (AL), the olfactory centre in the insect brain, shows that olfactory input to DA1 and VM2 glomeruli is also modulated by starvation. Knocking down insulin receptors in neurons converging onto the DA1 glomerulus suggests that insulin-signalling partly controls pheromone perception in the AL, and adjusts cVA attraction according to nutritional state and sexual receptivity in Drosophila females.

  • 16.
    Lehmann, Philipp
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Nylin, Sören
    Stockholm University, Faculty of Science, Department of Zoology.
    Gotthard, Karl
    Stockholm University, Faculty of Science, Department of Zoology.
    Carlsson, Mikael A.
    Stockholm University, Faculty of Science, Department of Zoology.
    Idiosyncratic development of sensory structures in brains of diapausing butterfly pupae: implications for information processing2017In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 284, no 1858, article id 20170897Article in journal (Refereed)
    Abstract [en]

    Diapause is an important escape mechanism from seasonal stress in many insects. A certain minimum amount of time in diapause is generally needed in order for it to terminate. The mechanisms of time-keeping in diapause are poorly understood, but it can be hypothesized that a well-developed neural system is required. However, because neural tissue is metabolically costly to maintain, there might exist conflicting selective pressures on overall brain development during diapause, on the one hand to save energy and on the other hand to provide reliable information processing during diapause. We performed the first ever investigation of neural development during diapause and non-diapause (direct) development in pupae of the butterfly Pieris napi from a population whose diapause duration is known. The brain grew in size similarly in pupae of both pathways up to 3 days after pupation, when development in the diapause brain was arrested. While development in the brain of direct pupae continued steadily after this point, no further development occurred during diapause until temperatures increased far after diapause termination. Interestingly, sensory structures related to vision were remarkably well developed in pupae from both pathways, in contrast with neuropils related to olfaction, which only developed in direct pupae. The results suggest that a well-developed visual system might be important for normal diapause development.

  • 17.
    Lehmann, Philipp
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Pruisscher, Peter
    Stockholm University, Faculty of Science, Department of Zoology.
    Posledovich, Diana
    Stockholm University, Faculty of Science, Department of Zoology.
    Carlsson, Mikael
    Stockholm University, Faculty of Science, Department of Zoology.
    Käkelä, Reijo
    Tang, Patrik
    Nylin, Sören
    Stockholm University, Faculty of Science, Department of Zoology.
    Wheat, Christopher W.
    Stockholm University, Faculty of Science, Department of Zoology.
    Wiklund, Christer
    Stockholm University, Faculty of Science, Department of Zoology.
    Gotthard, Karl
    Stockholm University, Faculty of Science, Department of Zoology.
    Energy and lipid metabolism during direct and diapause development in a pierid butterfly2016In: Journal of Experimental Biology, ISSN 0022-0949, E-ISSN 1477-9145, Vol. 219, no 19, p. 3049-3060Article in journal (Refereed)
    Abstract [en]

    Diapause is a fundamental component of the life-cycle in the majority of insects living in environments characterized by strong seasonality. The present study addresses poorly understood associations and trade-offs between endogenous diapause duration, thermal sensitivity of development, energetic cost of development and cold tolerance. Diapause intensity, metabolic rate trajectories and lipid profiles of directly developing and diapausing animals were studied using pupae and adults of Pieris napi butterflies from a population for which endogenous diapause is well studied. Endogenous diapause was terminated after 3 months and termination required chilling. Metabolic and postdiapause development rates increased with diapause duration, while the metabolic cost of postdiapause development decreased, indicating that once diapause is terminated development proceeds at a low rate even at low temperature. Diapausing pupae had larger lipid stores than the directly developing pupae and lipids constituted the primary energy source during diapause. However, during diapause lipid stores did not decrease. Thus, despite lipid catabolism meeting the low energy costs of the diapausing pupae, primary lipid store utilization did not occur until the onset of growth and metamorphosis in spring. In line with this finding, diapausing pupae contained low amounts of mitochondria-derived cardiolipins, which suggests a low capacity for fatty acid β-oxidation. While ontogenic development had a large effect on lipid and fatty acid profiles, only small changes in these were seen during diapause. The data therefore indicate that the diapause lipidomic phenotype is built early, when pupae are still at high temperature, and retained until diapause post-diapause development.

  • 18.
    Liu, Yiting
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Luo, Jiangnan
    Stockholm University, Faculty of Science, Department of Zoology. National Institutes of Health, Bethesda, MD, USA.
    Carlsson, Mikael A.
    Stockholm University, Faculty of Science, Department of Zoology.
    Nässel, Dick R.
    Stockholm University, Faculty of Science, Department of Zoology.
    Serotonin and insulin-like peptides modulate leucokinin-producing neurons that affect feeding and water homeostasis in Drosophila2015In: Journal of Comparative Neurology, ISSN 0021-9967, E-ISSN 1096-9861, Vol. 523, no 12, p. 1840-1863Article in journal (Refereed)
    Abstract [en]

    Metabolic homeostasis and water balance is maintained by tight hormonal and neuronal regulation. In Drosophila, insulin-like peptides (DILPs) are key regulators of metabolism, and the neuropeptide leucokinin (LK) is a diuretic hormone that also modulates feeding. However, it is not known whether LK and DILPs act together to regulate feeding and water homeostasis. Because LK neurons express the insulin receptor (dInR), we tested functional links between DILP and LK signaling in feeding and water balance. Thus, we performed constitutive and conditional manipulations of activity in LK neurons and insulin-producing cells (IPCs) in adult flies and monitored food intake, responses to desiccation, and peptide expression levels. We also measured in vivo changes in LK and DILP levels in neurons in response to desiccation and drinking. Our data show that activated LK cells stimulate diuresis in vivo, and that LK and IPC signaling affect food intake in opposite directions. Overexpression of the dInR in LK neurons decreases the LK peptide levels, but only caused a subtle decrease in feeding, and had no effect on water balance. Next we demonstrated that LK neurons express the serotonin receptor 5-HT1B. Knockdown of this receptor in LK neurons diminished LK expression, increased desiccation resistance, and diminished food intake. Live calcium imaging indicates that serotonin inhibits spontaneous activity in abdominal LK neurons. Our results suggest that serotonin via 5-HT1B diminishes activity in the LK neurons and thereby modulates functions regulated by LK peptide, but the action of the dInR in these neurons remains less clear.

  • 19.
    Lushchak, Oleh V.
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Carlsson, Mikael A.
    Stockholm University, Faculty of Science, Department of Zoology.
    Nässel, Dick R.
    Stockholm University, Faculty of Science, Department of Zoology.
    Food odors trigger an endocrine response that affects food ingestion and metabolism2015In: Cellular and Molecular Life Sciences (CMLS), ISSN 1420-682X, E-ISSN 1420-9071, Vol. 72, no 16, p. 3143-3155Article in journal (Refereed)
    Abstract [en]

    Food odors stimulate appetite and innate food-seeking behavior in hungry animals. The smell of food also induces salivation and release of gastric acid and insulin. Conversely, sustained odor exposure may induce satiation. We demonstrate novel effects of food odors on food ingestion, metabolism and endocrine signaling in Drosophila melanogaster. Acute exposure to attractive vinegar odor triggers a rapid and transient increase in circulating glucose, and a rapid upregulation of genes encoding the glucagon-like hormone adipokinetic hormone (AKH), four insulin-like peptides (DILPs) and some target genes in peripheral tissues. Sustained exposure to food odors, however, decreases food intake. Hunger-induced strengthening of synaptic signaling from olfactory sensory neurons (OSNs) to brain neurons increases food-seeking behavior, and conversely fed flies display reduced food odor sensitivity and feeding. We show that increasing the strength of OSN signaling chronically by genetic manipulation of local peptide neuromodulation reduces feeding, elevates carbohydrates and diminishes lipids. Furthermore, constitutively strengthened odor sensitivity altered gene transcripts for AKH, DILPs and some of their targets. Thus, we show that food odor can induce a transient anticipatory endocrine response, and that boosted sensitivity to this odor affects food intake, as well as metabolism and hormonal signaling.

  • 20.
    Schäpers, Alexander
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Carlsson, Mikael A.
    Stockholm University, Faculty of Science, Department of Zoology, Functional Morphology.
    Gamberale Stille, Gabriella
    Stockholm University, Faculty of Science, Department of Zoology, Ethology.
    Janz, Niklas
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    The Role of Olfactory Cues for the Search Behavior of a Specialist and Generalist Butterfly2015In: Journal of insect behavior, ISSN 0892-7553, E-ISSN 1572-8889, Vol. 28, no 1, p. 77-87Article in journal (Refereed)
    Abstract [en]

    Searching for resources is often a challenging task, especially for small organisms such as insects. Complex stimuli have to be extracted from the environment and translated into a relevant behavioral output. A first step in this process is to investigate the relative roles of the different senses during search for various resources. While the role of olfaction is well documented in nocturnal moths, the olfactory abilities of the closely related diurnal butterflies are poorly explored. Here we investigated how olfactory information is used in the search for host plants and asked if these abilities varied with levels of stimulus complexity. Thus, we tested two nymphalid butterfly species with divergent host plant range in a two-choice olfactometer testing different combinations of host and non-host plants. The experiments show both the monophagous Aglais urticae and the polyphagous Polygonia c-album could navigate towards an odor source, but this ability varied with context. While mated females exhibited a preference for their host plant, unmated females of both species did not show a preference for host plant cues. Furthermore, both species showed inabilities to make fine-tuned decisions between hosts. We conclude that olfactory cues are important for butterflies to navigate towards targets. We argue that there are limitations on how much information can be extracted from host volatiles. These results are discussed in the light of neural processing limitations and degree of host plant specialization, suggesting the necessity of other sensory modalities to sharpen the decision process and facilitate the final oviposition event.

  • 21.
    Schäpers, Alexander
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Nylin, Sören
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Carlsson, Mikael A.
    Stockholm University, Faculty of Science, Department of Zoology, Functional Morphology.
    Janz, Niklas
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Specialist and generalist oviposition strategies in butterflies: maternal care or precocious young?2016In: Oecologia, ISSN 0029-8549, E-ISSN 1432-1939, Vol. 180, no 2, p. 335-343Article in journal (Refereed)
    Abstract [en]

    Herbivorous insects specialized on a narrow set of plants are believed to be better adapted to their specific hosts. This hypothesis is supported by observations of herbivorous insect species with a broader diet breadth which seemingly pay a cost through decreased oviposition accuracy. Despite many studies investigating female oviposition behavior, there is a lack of knowledge on how larvae cope behaviorally with their mothers' egg-laying strategies. We have examined a unique system of five nymphalid butterfly species with different host plant ranges that all feed on the same host plant. The study of this system allowed us to compare at the species level how oviposition preference is related to neonate larval responses in several disadvantageous situations. We found a general co-adaptation between female and larval abilities, where species with more discriminating females had larvae that were less able to deal with a suboptimal initial feeding site. Conversely, relatively indiscriminate females had more precocious larvae with better abilities to cope with suboptimal sites. Despite similarities between the tested species with similar host ranges, there were also striking differences. Generalist and specialist species can be found side by side in many clades, with each clade having a specific evolutionary history. Such clade-specific, phylogenetically determined preconditions apparently have affected how precisely a broad or narrow diet breadth can be realized.

  • 22.
    Söderberg, Jeannette A. E.
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Carlsson, Mikael A.
    Stockholm University, Faculty of Science, Department of Zoology.
    Nässel, Dick R.
    Stockholm University, Faculty of Science, Department of Zoology.
    Insulin-producing cells in the Drosophila brain also express satiety-inducing cholecystokinin-like peptide, drosulfakinin2012In: Frontiers in Endocrinology, ISSN 1664-2392, E-ISSN 1664-2392, Vol. 3, article id 109Article in journal (Refereed)
    Abstract [en]

    Regulation of meal size and assessing the nutritional value of food are two important aspects of feeding behavior. The mechanisms that regulate these two aspects have not been fully elucidated in Drosophila. Diminished signaling with insulin-like peptides Drosophila insulin-like peptides (DILPs) affects food intake in flies, but it is not clear what signal(s) mediates satiety. Here we investigate the role of DILPs and drosulfakinins (DSKs), cholecystokinin-like peptides, as satiety signals in Drosophila. We show that DSKs and DILPs are co-expressed in insulin-producing cells (IPCs) of the brain. Next we analyzed the effects of diminishing DSKs or DILPs employing the Gal4-UAS system by (1) diminishing DSK-levels without directly affecting DILP levels by targeted Dsk-RNAi, either in all DSK-producing cells (DPCs) or only in the IPCs or (2) expressing a hyperpolarizing potassium channel to inactivate either all the DPCs or only the IPCs, affecting release of both peptides. The transgenic flies were assayed for feeding and food choice, resistance to starvation, and for levels of Dilp and Dsk transcripts in brains of fed and starved animals. Diminishment of DSK in the IPCs alone is sufficient to cause defective regulation of food intake and food choice, indicating that DSK functions as a hormonal satiety signal in Drosophila. Quantification of Dsk and Dilp transcript levels reveals that knockdown of either peptide type affects the transcript levels of the other, suggesting a possible feedback regulation between the two signaling pathways. In summary, DSK and DILPs released from the IPCs regulate feeding, food choice and metabolic homeostasis in Drosophila in a coordinated fashion.

  • 23.
    Söderberg, Jeannette A.E.
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Functional Morphology.
    Carlsson, Mikael A.
    Stockholm University, Faculty of Science, Department of Zoology, Functional Morphology.
    Nässel, Dick R.
    Stockholm University, Faculty of Science, Department of Zoology, Functional Morphology.
    Insulin-producing cells in the Drosophila brain co-localize a satiety-inducing cholecystokinin-like peptide, DSKManuscript (preprint) (Other academic)
  • 24.
    Van Dijk, Laura J. A.
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Janz, Niklas
    Stockholm University, Faculty of Science, Department of Zoology.
    Schäpers, Alexander
    Stockholm University, Faculty of Science, Department of Zoology.
    Gamberale-Stille, Gabriella
    Stockholm University, Faculty of Science, Department of Zoology.
    Carlsson, Mikael A.
    Stockholm University, Faculty of Science, Department of Zoology.
    Experience-dependent mushroom body plasticity in butterflies: consequences of search complexity and host range2017In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 284, no 1866, article id 20171594Article in journal (Refereed)
    Abstract [en]

    An ovipositing insect experiences many sensory challenges during her search for a suitable host plant. These sensory challenges become exceedingly pronounced when host range increases, as larger varieties of sensory inputs have to be perceived and processed in the brain. Neural capacities can be exceeded upon information overload, inflicting costs on oviposition accuracy. One presumed generalist strategy to diminish information overload is the acquisition of a focused search during its lifetime based on experiences within the current environment, a strategy opposed to a more genetically determined focus expected to be seen in relative specialists. We hypothesized that a broader host range is positively correlated with mushroom body (MB) plasticity, a brain structure related to learning and memory. To test this hypothesis, butterflies with diverging host ranges (Polygonia c-album, Aglais io and Aglais urticae) were subjected to differential environmental complexities for oviposition, after which ontogenetic MB calyx volume differences were compared among species. We found that the relative generalist species exhibited remarkable plasticity in ontogenetic MB volumes; MB growth was differentially stimulated based on the complexity of the experienced environment. For relative specialists, MB volume was more canalized. All in all, this study strongly suggests an impact of host range on brain plasticity in Nymphalid butterflies.

  • 25.
    Verschut, Thomas A.
    et al.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Carlsson, Mikael A.
    Stockholm University, Faculty of Science, Department of Zoology, Functional Morphology.
    Anderson, Peter
    Hambäck, Peter A.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Sensory mutations in Drosophila melanogaster influence associational effects between resources during oviposition2017In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7, article id 9352Article in journal (Refereed)
    Abstract [en]

    Neighboring resources can affect insect oviposition behavior when the complexity of sensory information obscures information about host resource availability in heterogeneous resource patches. These effects are referred to as associational effects and are hypothesized to occur through constraints in the sensory processing of the insect during host search, resulting into suboptimal resource use. Because the possibilities to study these constraints on naturally occurring animals are limited, we instead used sensory mutants of Drosophila melanogaster to determine the importance of sensory information in the occurrence of associational effects. We found that oviposition was mainly governed by non-volatile chemical cues and less by volatile cues. Moreover, the loss of gustatory sensilla resulted in random resource selection and eliminated associational effects. In conclusion, our study shows that associational effects do not necessarily depend on constraints in the sensory evaluation of resource quality, but may instead be a direct consequence of distinctive selection behavior between different resources at small scales.

  • 26.
    Verschut, Thomas A.
    et al.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences. Stockholm University, Faculty of Science, Department of Zoology.
    Carlsson, Mikael A.
    Stockholm University, Faculty of Science, Department of Zoology.
    Hambäck, Peter A.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Scaling the interactive effects of attractive and repellent odours for insect search behaviour2019In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 9, article id 15309Article in journal (Refereed)
    Abstract [en]

    Insects searching for resources are exposed to a complexity of mixed odours, often involving both attractant and repellent substances. Understanding how insects respond to this complexity of cues is crucial for understanding consumer-resource interactions, but also to develop novel tools to control harmful pests. To advance our understanding of insect responses to combinations of attractive and repellent odours, we formulated three qualitative hypotheses; the response-ratio hypothesis, the repellent-threshold hypothesis and the odour-modulation hypothesis. The hypotheses were tested by exposing Drosophila melanogaster in a wind tunnel to combinations of vinegar as attractant and four known repellents; benzaldehyde, 1-octen-3-ol, geosmin and phenol. The responses to benzaldehyde, 1-octen-3-ol and geosmin provided support for the response-ratio hypothesis, which assumes that the behavioural response depends on the ratio between attractants and repellents. The response to phenol, rather supported the repellent-threshold hypothesis, where aversion only occurs above a threshold concentration of the repellent due to overshadowing of the attractant. We hypothesize that the different responses may be connected to the localization of receptors, as receptors detecting phenol are located on the maxillary palps whereas receptors detecting the other odorants are located on the antennae.

  • 27.
    Verschut, Thomas A.
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Functional Morphology.
    Farnier, Kevin
    Cunningham, J. Paul
    Carlsson, Mikael A.
    Stockholm University, Faculty of Science, Department of Zoology, Functional Morphology.
    Behavioral and Physiological Evidence for Palp Detection of the Male-Specific Attractant Cuelure in the Queensland Fruit Fly (Bactrocera tryoni)2018In: Frontiers in Physiology, ISSN 1664-042X, E-ISSN 1664-042X, Vol. 9, article id 990Article in journal (Refereed)
    Abstract [en]

    The Queensland fruit fly, Bactrocera tryoni, is considered one of the worst horticultural pests in Australia attacking a large variety of fruit crops. To defeat pest insects, olfactory attractants have been developed and widely used in lure and kill strategies. Male B. tryoni are strongly attracted to the compound raspberry ketone and its synthetic analog, cuelure. Despite the strong behavioral response, a recent study failed to show any activation of antennal receptors to cuelure. Therefore, we hypothesized that cuelure may be detected by an accessory olfactory organ, the maxillary palp. Combining behavioral and physiological experiments we clearly demonstrate that male flies, but not female flies, primarily use the maxillary palps and not the antennae to detect and respond to cuelure. Furthermore, regardless of satiety status, male flies always preferred cuelure over a sugar rich source, unless the maxillary palps were excised.

1 - 27 of 27
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf