Publications by authors named "Sylvain Hugel"

36 Publications

Somatostatin analogue pasireotide (SOM230) inhibits catecholamine secretion in human pheochromocytoma cells.

Cancer Lett 2021 Oct 9. Epub 2021 Oct 9.

Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, F-67000, Strasbourg, France. Electronic address:

Increasingly common, neuroendocrine tumors (NETs) are regarded nowadays as neoplasms potentially causing debilitating symptoms and life-threatening medical conditions. Pheochromocytoma is a NET that develops from chromaffin cells of the adrenal medulla, and is responsible for an excessive secretion of catecholamines. Consequently, patients have an increased risk for clinical symptoms such as hypertension, elevated stroke risk and various cardiovascular complications. Somatostatin analogues are among the main anti-secretory medical drugs used in current clinical practice in patient with NETs. However, their impact on pheochromocytoma-associated catecholamine hypersecretion remains incompletely explored. This study investigated the potential efficacy of octreotide and pasireotide (SOM230) on human tumor cells directly cultured from freshly resected pheochromocytomas using an implemented catecholamine secretion measurement by carbon fiber amperometry. SOM230 treatment efficiently inhibited nicotine-induced catecholamine secretion both in bovine chromaffin cells and in human tumor cells whereas octreotide had no effect. Moreover, SOM230 specifically decreased the number of exocytic events by impairing the stimulation-evoked calcium influx as well as the nicotinic receptor-activated inward current in human pheochromocytoma cells. Altogether, our findings indicate that SOM230 acts as an inhibitor of catecholamine secretion through a mechanism involving the nicotinic receptor and might be considered as a potential anti-secretory treatment for patients with pheochromocytoma.
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http://dx.doi.org/10.1016/j.canlet.2021.10.009DOI Listing
October 2021

Inhibitory interneurons with differential plasticities at their connections tune excitatory/inhibitory balance in the spinal nociceptive system.

Pain 2021 Aug 30. Epub 2021 Aug 30.

Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, 67000 Strasbourg, France.

Abstract: Networks of the dorsal-horn of the spinal-cord process nociceptive information from the periphery. In these networks, the excitation/inhibition balance is critical to shape this nociceptive information and to gate it to the brain where it is interpreted as pain. Our aim was to define whether short-term plasticity of inhibitory connections could tune this inhibition/excitation balance by differentially controlling excitatory and inhibitory microcircuits. To this end, we used spinal-cord slices from adult mice expressing enhanced green fluorescent protein (eGFP) under the GAD65 promoter and recorded from both eGFP+ (putative inhibitory) and eGFP- (putative excitatory) neurons of lamina II while stimulating single presynaptic GABAergic interneurons at various frequencies. Our results indicate that GABAergic neurons of lamina II simultaneously contact eGFP- and eGFP+ neurons, but these connections display very different frequency-dependent short-term plasticities. Connections onto eGFP- interneurons displayed limited frequency-dependent changes, and strong time-dependent summation of inhibitory synaptic currents that was however subjected to a tonic activity-dependent inhibition involving A1 adenosine receptors. In contrast, GABAergic connections onto eGFP+ interneurons expressed pronounced frequency-dependent depression, thus favoring disinhibition at these synapses by a mechanism involving the activation of GABAB autoreceptors at low frequency. Interestingly, the balance favors inhibition at frequencies associated with intense pain whether it favors excitation at frequencies associated with low pain. Therefore, these target- and frequency-specific plasticities allow to tune the balance between inhibition and disinhibition while processing frequency-coded information from primary afferents. These short-term plasticities and their modulation by A1 and GABAB receptors might represent an interesting target in pain-alleviating strategies.
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http://dx.doi.org/10.1097/j.pain.0000000000002460DOI Listing
August 2021

New intertidal crickets from Comoros and Mascarene islands (Orthoptera: Trigonidiidae: Nemobiinae: Burcini).

Zootaxa 2021 Jun 29;4995(1):1-26. Epub 2021 Jun 29.

Institut de Systématique, Evolution et Biodiversité, Muséum national d'Histoire naturelle, CNRS, Sorbonne Université, EPHE, Université des Antilles, Case postale 50 (Entomologie), 57 rue Cuvier, F-75231 Paris cedex 05, France. .

Nemobiinae crickets of the tribe Burcini Gorochov, 1986 are described for the first time from the shores of South Western Indian Ocean islands. The new genus Makalapobius n. gen. is proposed to include M. aigrettensis n. gen. n. sp. from Mauritius and M. masihu n. gen. n. sp. from Grande Comore, and the new genus Gabusibius n. gen. to include G. ndzilu n. gen. n. sp. from Anjouan, G. mosi n. gen. n. sp., from Mohéli, and G. dzindzanu n. gen. n. sp. from Mayotte. The species Speonemobius littoreus Vannini Chelazzi, 1978 from Somalia coast is tentatively placed in the genus Gabusibius n. gen. as G. ? litoreus (Vannini Chelazzi, 1978) n. gen. n. comb. The songs of G. mosi n. gen. n. sp. and M. aigrettensis n. gen. n. sp. are described. The threats to SWIO Burcini and endemism of Orthoptera from SWIO coastal areas are discussed.
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http://dx.doi.org/10.11646/zootaxa.4995.1.1DOI Listing
June 2021

[Nociception pain and autism].

Med Sci (Paris) 2021 Feb 16;37(2):141-151. Epub 2021 Feb 16.

CNRS, 5 rue Blaise-Pascal, 67000 Strasbourg, France.

Autistic subjects frequently display sensory anomalies. Those regarding nociception and its potential outcome, pain, are of crucial interest. Indeed, because of numerous comorbidities, autistic subjects are more often exposed to painful situation. Despite being often considered as less sensitive, experimental studies evaluating this point are failing to reach consensus. Using animal model can help reduce variability and bring, regarding autism, an overview of potential alterations of the nociceptive system at the cellular and molecular level.
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http://dx.doi.org/10.1051/medsci/2020280DOI Listing
February 2021

Edible Crickets (Orthoptera) Around the World: Distribution, Nutritional Value, and Other Benefits-A Review.

Front Nutr 2020 12;7:537915. Epub 2021 Jan 12.

International Center of Insect Physiology and Ecology (icipe), Nairobi, Kenya.

Edible crickets are among the praised insects that are gaining recognition as human food and livestock feed with a potential of contributing to food security and reduction of malnutrition. Globally, the sustainable use of crickets as food or feed is undermined by lack of information on the number of the edible crickets, the country where they are consumed, and the developmental stages consumed. Furthermore, lack of data on their nutritional content and the potential risks to potential consumers limits their consumption or inclusion into other food sources. We reviewed published literature on edible cricket species, countries where they are consumed, and the stage at which they are consumed. We further reviewed information on their nutritional content, the safety of cricket consumption, and the sensory qualities of the edible crickets. We also looked at other benefits derived from the crickets, which include ethnomedicine, livestock feed, pest management strategies, contribution to economic development, and livelihood improvement, particularly in terms of use as food preservatives and use within music, sports, and cultural entomology. Lastly, we reviewed information on the farming of edible crickets. In this review, we report over 60 cricket species that are consumed in 49 countries globally. Nutritionally, crickets are reported to be rich in proteins, ranging from 55 to 73%, and lipids, which range from 4.30 to 33.44% of dry matter. The reported amount of polyunsaturated fatty acids (PUFA) is 58% of the total fatty acids. Edible crickets contain an appreciable amount of macro- and micro-mineral elements such as calcium, potassium, magnesium, phosphorus, sodium, iron, zinc, manganese, and copper. Also, the crickets are rich in the required amount of vitamins such as B group vitamins and vitamins A, C, D, E, and K. Overall, the cricket species examined in this review are safe to be consumed, and they display high proximate content that can replace plant and livestock products. The crickets play valuable roles in contributing to the economies of many countries and livelihoods, and they have medicinal and social benefits. This review is expected to promote greater recognition of crickets as a source of food, feed, and other benefits in the world and encourage up-scaling by farming them for sustainable utilization.
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http://dx.doi.org/10.3389/fnut.2020.537915DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7835793PMC
January 2021

Involvement of the lateral habenula in fear memory.

Brain Struct Funct 2020 Sep 8;225(7):2029-2044. Epub 2020 Jul 8.

Université de Strasbourg, Centre National de La Recherche Scientifique, Laboratoire de Neurosciences Cognitives Et Adaptatives (LNCA), UMR 7364, 12 rue Goethe, 67000, Strasbourg, France.

Increasing evidence points to the engagement of the lateral habenula (LHb) in the selection of appropriate behavioral responses in aversive situations. However, very few data have been gathered with respect to its role in fear memory formation, especially in learning paradigms in which brain areas involved in cognitive processes like the hippocampus (HPC) and the medial prefrontal cortex (mPFC) are required. A paradigm of this sort is trace fear conditioning, in which an aversive event is preceded by a discrete stimulus, generally a tone, but without the close temporal contiguity allowing for their association based on amygdala-dependent information processing. In a first experiment, we analyzed cellular activations (c-Fos expression) induced by trace fear conditioning in subregions of the habenular complex, HPC, mPFC and amygdala using a factorial analysis to unravel functional networks through correlational analysis of data. This analysis suggested that distinct LHb subregions engaged in different aspects of conditioning, e.g. associative processes and onset of fear responses. In a second experiment, we performed chemogenetic LHb inactivation during the conditioning phase of the trace fear conditioning paradigm and subsequently assessed contextual and tone fear memories. Whereas LHb inactivation did not modify rat's behavior during conditioning, it induced contextual memory deficits and enhanced fear to the tone. These results demonstrate the involvement of the LHb in fear memory. They further suggest that the LHb is engaged in learning about threatening environments through the selection of relevant information predictive of a danger.
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http://dx.doi.org/10.1007/s00429-020-02107-5DOI Listing
September 2020

Evidence for Common Horizontal Transmission of among Ants and Ant Crickets: Kleptoparasitism Added to the List.

Microorganisms 2020 May 27;8(6). Epub 2020 May 27.

Research Institute for Sustainable Humanosphere, Kyoto University, Kyoto 611-0011, Japan.

While , an intracellular bacterial symbiont, is primarily transmitted maternally in arthropods, horizontal transmission between species has been commonly documented. We examined kleptoparasitism as a potential mechanism for horizontal transmission, using ant crickets and their host ants as the model system. We compared prevalence and diversity of across multiple ant cricket species with different degrees of host specificity/integration level. Our analyses revealed at least three cases of inter-ordinal transfer among ant and ant crickets, and also showed that ant cricket species with high host-integration and host-specificity tend to harbor a higher prevalence and diversity than other types of ant crickets. This study provides empirical evidence that distribution of across ant crickets is largely attributable to horizontal transmission, but also elucidates the role of intimate ecological association in successful horizontal transmission.
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http://dx.doi.org/10.3390/microorganisms8060805DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7355411PMC
May 2020

First record of shield-backed katydids in Madagascar with the description of a new genus and three new species (Orthoptera: Ensifera: Tettigoniidae: Tettigoniinae: Arytropteridini).

Authors:
Sylvain Hugel

Zootaxa 2019 Dec 11;4706(4):zootaxa.4706.4.4. Epub 2019 Dec 11.

INCI, UPR 3212 CNRS, Université de Strasbourg, 8, allée du Général Rouvillois, F-67000 Strasbourg Cedex..

Shield-backed katydids of tribe Arytropteridini Caudell, 1908 are recorded for the first time in Madagascar. The new genus Toliaridectes n. gen. is proposed to include three new species from the south west of the island: Toliaridectes meridionalis n. gen. n. sp., Toliaridectes wendenbaumi n. gen. n. sp. and Toliaridectes antsycurvis n. gen. n. sp.. Elements of biology of Toliaridectes n. gen. are given and the call of Toliaridectes antsycurvis n. gen. n. sp. is described. The taxonomic position of Arytropteridini is discussed.
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http://dx.doi.org/10.11646/zootaxa.4706.4.4DOI Listing
December 2019

Diversity and Use of Edible Grasshoppers, Locusts, Crickets, and Katydids (Orthoptera) in Madagascar.

Foods 2019 Dec 10;8(12). Epub 2019 Dec 10.

California Academy of Sciences, San Francisco, CA 94118, USA.

Madagascar has a long history of using Orthoptera as food and feed. Our understanding of the biological diversity of this resource, its contemporary use, and its future potentials in Madagascar is extremely limited. The present study contributes basic knowledge of the biological diversity and local uses of edible Orthoptera in Malagasy food cultures. Data was collected with key informants in 47 localities covering most of the ecoregions of Madagascar and corresponding to 12 of the 19 ethnic groups. Orthoptera are consumed throughout Madagascar. We report 37 edible Orthoptera species, of which 28 are new species records of edible Orthoptera in Madagascar and 24 are new species records of edible Orthoptera in the world. Most species are endemic and occur in farming zones. Children are the primary collectors and consumers of edible Orthoptera. The insects are eaten both as snacks and main meals. Edible Orthoptera are primarily collected casually and marketing is rare, with the notable exceptions of the large cricket and during locust outbreaks (e.g., ). The use of Orthoptera as feed seems rare. Further investigations of cultural and personal preferences are required to assess the future potential roles of Orthoptera in Malagasy food habits.
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http://dx.doi.org/10.3390/foods8120666DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6963331PMC
December 2019

Performance of Newly Described Native Edible Cricket Scapsipedus icipe (Orthoptera: Gryllidae) on Various Diets of Relevance for Farming.

J Econ Entomol 2019 03;112(2):653-664

International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya.

A new native edible cricket species, Scapsipedus icipe Hugel and Tanga, has been described in Kenya for the first time. However, there is lack of information on suitable diets and their effects on the developmental time, survival, weight gain, body length, growth index, preoviposition, oviposition, postoviposition, fecundity, egg eclosion period, adult emergence, and longevity of this species, which are prerequisite for large-scale production. In this study, six diets (wheat bran, soybean, fish offal, pumpkin leaf, carrot, and maize meals) selected to vary in protein, carbohydrate, and fat content were evaluated. The developmental time and survival rate of the different life stages varied considerably on the various diets, with the shortest development and highest survival rate recorded when fed wheat bran diet. Preoviposition duration was significantly longer on maize and carrot diets (>10 d) compared with that recorded on the other diets (<8 d). Body weight and body length were significantly influenced by the different diets tested. Females of S. icipe fed on protein-rich diets (fish offal, soybean, and wheat bran) had significantly higher lifetime fecundity and fertility. Female-biased sex ratio was recorded on wheat bran and soybean diets, whereas male-biased sex ratio was recorded on maize and carrot diets. Our findings reveal that the impact of diet quality on the biological fitness parameters of S. icipe and the implication of the results are discussed in light of effective mass rearing of this species.
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http://dx.doi.org/10.1093/jee/toy397DOI Listing
March 2019

A new edible cricket species from Africa of the genus Scapsipedus.

Zootaxa 2018 Sep 28;4486(3):393-392. Epub 2018 Sep 28.

International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772, Nairobi, Kenya.

A new cricket of the genus Scapsipedus is described from Kenya. The distribution, acoustic behavior, including call and courtship song, mitochondrial sequences, and data on the biology of that new species are given. This edible cricket is a very promising species for mass production for food and feed.
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http://dx.doi.org/10.11646/zootaxa.4486.3.9DOI Listing
September 2018

A new genus and five new species of Anostostomatidae from the Lesser Antilles (Orthoptera: Ensifera).

Zootaxa 2018 May 31;4425(3):511-526. Epub 2018 May 31.

INCI, UPR 3212 CNRS, Université de Strasbourg, 5, rue Blaise Pascal, F-67084 Strasbourg Cedex..

Most high volcanic islands of Lesser Antilles harbor one single genus of Anostostomatidae: Rhumosa n. gen: Rhumosa bolognei n. gen. n. sp. in Guadeloupe, Rhumosa macoucheriei n. gen. n. sp. in Dominica, Rhumosa depazei n. gen. n. sp. in Martinique, Rhumosa admiralrodneyei n. gen. n. sp. in Saint Lucia, Rhumosa captainblighei n. gen. n. sp., in Saint Vincent. These species are restricted to well preserved rainforests; species from northern islands apparently occurring at higher elevation than species of southern islands. The distribution and generic position of Rhumosa n. gen. species is discussed, as well as the generic position of Lutosa cubaensis (Haan, 1843).
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http://dx.doi.org/10.11646/zootaxa.4425.3.5DOI Listing
May 2018

WNK1 kinase and its partners Akt, SGK1 and NBC-family Na/HCO3 cotransporters are potential therapeutic targets for glioblastoma stem-like cells linked to Bisacodyl signaling.

Oncotarget 2018 Jun 5;9(43):27197-27219. Epub 2018 Jun 5.

Laboratoire d'Innovation Thérapeutique, Centre National de la Recherche Scientifique/Université de Strasbourg, UMR7200, Laboratoire d'Excellence Medalis, Faculté de Pharmacie, Illkirch 67401, France.

Glioblastoma is a highly heterogeneous brain tumor. The presence of cancer cells with stem-like and tumor initiation/propagation properties contributes to poor prognosis. Glioblastoma cancer stem-like cells (GSC) reside in hypoxic and acidic niches favoring cell quiescence and drug resistance. A high throughput screening recently identified the laxative Bisacodyl as a cytotoxic compound targeting quiescent GSC placed in acidic microenvironments. Bisacodyl activity requires its hydrolysis into DDPM, its pharmacologically active derivative. Bisacodyl was further shown to induce tumor shrinking and increase survival in glioblastoma models. Here we explored the cellular mechanism underlying Bisacodyl cytotoxic effects using quiescent GSC in an acidic microenvironment and GSC-derived 3D macro-spheres. These spheres mimic many aspects of glioblastoma tumors , including hypoxic/acidic areas containing quiescent cells. Phosphokinase protein arrays combined with pharmacological and genetic modulation of signaling pathways point to the WNK1 serine/threonine protein kinase as a mediator of Bisacodyl cytotoxic effect in both cell models. WNK1 partners including the Akt and SGK1 protein kinases and NBC-family Na/HCO3 cotransporters were shown to participate in the compound's effect on GSC. Overall, our findings uncover novel potential therapeutic targets for combatting glioblastoma which is presently an incurable disease.
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http://dx.doi.org/10.18632/oncotarget.25509DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6007472PMC
June 2018

Hyperactivity of Anterior Cingulate Cortex Areas 24a/24b Drives Chronic Pain-Induced Anxiodepressive-like Consequences.

J Neurosci 2018 03 20;38(12):3102-3115. Epub 2018 Feb 20.

Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, 67000 Strasbourg, France,

Pain associates both sensory and emotional aversive components, and often leads to anxiety and depression when it becomes chronic. Here, we characterized, in a mouse model, the long-term development of these sensory and aversive components as well as anxiodepressive-like consequences of neuropathic pain and determined their electrophysiological impact on the anterior cingulate cortex (ACC, cortical areas 24a/24b). We show that these symptoms of neuropathic pain evolve and recover in different time courses following nerve injury in male mice. electrophysiological recordings evidence an increased firing rate and bursting activity within the ACC when anxiodepressive-like consequences developed, and this hyperactivity persists beyond the period of mechanical hypersensitivity. Whole-cell patch-clamp recordings also support ACC hyperactivity, as shown by increased excitatory postsynaptic transmission and contribution of NMDA receptors. Optogenetic inhibition of the ACC hyperactivity was sufficient to alleviate the aversive and anxiodepressive-like consequences of neuropathic pain, indicating that these consequences are underpinned by ACC hyperactivity. Chronic pain is frequently comorbid with mood disorders, such as anxiety and depression. It has been shown that it is possible to model this comorbidity in animal models by taking into consideration the time factor. In this study, we aimed at determining the dynamic of different components and consequences of chronic pain, and correlated them with electrophysiological alterations. By combining electrophysiological, optogenetic, and behavioral analyses in a mouse model of neuropathic pain, we show that the mechanical hypersensitivity, ongoing pain, anxiodepressive consequences, and their recoveries do not necessarily exhibit temporal synchrony during chronic pain processing, and that the hyperactivity of the anterior cingulate cortex is essential for driving the emotional impact of neuropathic pain.
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http://dx.doi.org/10.1523/JNEUROSCI.3195-17.2018DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6596067PMC
March 2018

3-D imaging reveals four extraordinary cases of convergent evolution of acoustic communication in crickets and allies (Insecta).

Sci Rep 2017 08 2;7(1):7099. Epub 2017 Aug 2.

Institut de Systématique, Évolution, Biodiversité, ISYEB - UMR 7205 - CNRS, MNHN, UPMC, EPHE, Muséum national d'Histoire naturelle, Sorbonne Universités, 57 rue Cuvier, CP 50, Entomologie, F-75005, Paris, France.

When the same complex trait is exhibited by closely related species, a single evolutionary origin is frequently invoked. The complex stridulatory apparatus present in the forewings of extant crickets, mole crickets, katydids, and prophalangopsids, is currently interpreted as sharing a single common origin due to their similarity and unique function. An alternative hypothesis of convergent evolution in these ensiferan groups has challenged this common view, but remained controversial because of competing interpretations of wing venation. Here we propose another hypothesis for the widely and long debated homology of ensiferan stridulatory apparatus, performing the first 3D reconstruction of hidden structures at the wing bases. This approach allowed defining the homology of each vein from its very origin rather than after its more distal characteristics, which may be subjected to environmental pressure of selection. The stridulatory apparatus involves different veins in these four singing clades. In light of the most recent phylogenetic evidence, this apparatus developed four times in Ensifera, illustrating extraordinary convergent evolutions between closely related clades, by far exceeding the number of evolutionary steps ever proposed for calling ability in this group.
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http://dx.doi.org/10.1038/s41598-017-06840-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5541040PMC
August 2017

Insect mimicry of plants dates back to the Permian.

Nat Commun 2016 12 20;7:13735. Epub 2016 Dec 20.

Institut de Systématique, Évolution, Biodiversité, ISYEB, UMR 7205, CNRS, MNHN, UPMC, EPHE, Muséum national d'Histoire naturelle, Sorbonne Universités, 57 rue Cuvier, CP 50, Entomologie, F-75005, Paris, France.

In response to predation pressure, some insects have developed spectacular plant mimicry strategies (homomorphy), involving important changes in their morphology. The fossil record of plant mimicry provides clues to the importance of predation pressure in the deep past. Surprisingly, to date, the oldest confirmed records of insect leaf mimicry are Mesozoic. Here we document a crucial step in the story of adaptive responses to predation by describing a leaf-mimicking katydid from the Middle Permian. Our morphometric analysis demonstrates that leaf-mimicking wings of katydids can be morphologically characterized in a non-arbitrary manner and shows that the new genus and species Permotettigonia gallica developed a mimicking pattern of forewings very similar to those of the modern leaf-like katydids. Our finding suggests that predation pressure was already high enough during the Permian to favour investment in leaf mimicry.
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http://dx.doi.org/10.1038/ncomms13735DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5187432PMC
December 2016

Neuronal networks and nociceptive processing in the dorsal horn of the spinal cord.

Neuroscience 2016 Dec 3;338:230-247. Epub 2016 Sep 3.

Institut des Neurosciences Cellulaires et Intégratives, UPR3212, Centre National de la Recherche Scientifique, 67084 Strasbourg, France; Université de Strasbourg, 67084 Strasbourg, France. Electronic address:

The dorsal horn (DH) of the spinal cord receives a variety of sensory information arising from the inner and outer environment, as well as modulatory inputs from supraspinal centers. This information is integrated by the DH before being forwarded to brain areas where it may lead to pain perception. Spinal integration of this information relies on the interplay between different DH neurons forming complex and plastic neuronal networks. Elements of these networks are therefore potential targets for new analgesics and pain-relieving strategies. The present review aims at providing an overview of the current knowledge on these networks, with a special emphasis on those involving interlaminar communication in both physiological and pathological conditions.
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http://dx.doi.org/10.1016/j.neuroscience.2016.08.048DOI Listing
December 2016

First occurrence of Nemobiinae crickets in the Lesser Antilles (Orthoptera, Grylloidea, Trigonidiidae), with the descriptions of three new species.

Zootaxa 2016 Sep 15;4168(2):313-326. Epub 2016 Sep 15.

INCI, UPR 3212 CNRS, Université de Strasbourg, 8, rue Blaise Pascal, F-67084 Strasbourg Cedex.; Email:

The occurrence of Nemobiinae crickets (Grylloidea, Trigonidiidae) in the Lesser Antilles is attested here for the first time, by the descriptions of three new species of Absonemobius Desutter-Grandcolas, 1993 from Guadeloupe, St. Lucia and St. Vincent: Absonemobius septentrion n. sp., Absonemobius lucensis n. sp. and Absonemobius vincenti n. sp., and the discovery of Hygronemobius Hebard, 1913 in Guadeloupe. The generic attribution of several nemobiine species described from the Caribbean and from Southern Central America are also reviewed: Nemobius elegans Otte, 2006 from Costa Rica and Pteronemobius sanaco Otte & Perez-Gelabert, 2009 described from Belize are transferred to Hygronemobius; Hygronemobius darienicus Hebard, 1913 described from Panama is transferred to Absonemobius Desutter-Grandcolas, 1993; Hygronemobius epia Otte & Perez-Gelabert, 2009 does not belong to Hygronemobius, but is temporarily kept in this genus as incertae sedis.
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http://dx.doi.org/10.11646/zootaxa.4168.2.5DOI Listing
September 2016

Mouthparts and nectar feeding of the flower visiting cricket Glomeremus orchidophilus (Gryllacrididae).

Arthropod Struct Dev 2016 May 9;45(3):221-9. Epub 2016 Apr 9.

Institut des Neurosciences Cellulaires et Intégratives, CNRS-Université de Strasbourg, 7 rue Blaise Pascal, 67084, Strasbourg, France.

Glomeremus orchidophilus (Gryllacrididae) is a flower visiting cricket on the tropical island La Réunion. This species is the only Orthoptera shown to be a pollinator of a plant. We studied its nectar feeding behavior and mouthpart morphology in detail. Since G. orchidophilus possesses biting-and-chewing mouthparts, our objective was to find behavioral and/or structural specializations for nectar-feeding. The comparative analysis of feeding behavior revealed that fluid is taken up without movements of the mouthparts in Glomeremus. A comparative morphological examination of two Glomeremus species, together with several representatives of other Gryllacrididae and other Ensifera taxa revealed subtle adaptations to fluid feeding in Glomeremus. All representatives of Gryllacrididae were found to possess a distinct patch of microtrichia at the tip of their galeae. However, in Glomeremus a channel is formed between the distal components of the maxillae and the mandibles on each side of the body. Micro-CT and SEM examination revealed a longitudinal groove that extends over the galea beginning at the patch of microtrichia in the studied Glomeremus species. We hypothesize that the microtrichia take up fluid by capillarity and the action of the cibarium and pharyngeal pumps transports fluid along the channels between the maxillae and mandibles into the preoral cavity. These mouthpart features allow nectar uptake from flowers that is unique in Orthoptera.
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http://dx.doi.org/10.1016/j.asd.2016.03.002DOI Listing
May 2016

Predicting Where a Radiation Will Occur: Acoustic and Molecular Surveys Reveal Overlooked Diversity in Indian Ocean Island Crickets (Mogoplistinae: Ornebius).

PLoS One 2016 12;11(2):e0148971. Epub 2016 Feb 12.

Université de La Réunion, UMR PVBMT, 7 chemin de l'IRAT, Ligne Paradis, 97410 Saint Pierre, Réunion, France.

Recent theory suggests that the geographic location of island radiations (local accumulation of species diversity due to cladogenesis) can be predicted based on island area and isolation. Crickets are a suitable group for testing these predictions, as they show both the ability to reach some of the most isolated islands in the world, and to speciate at small spatial scales. Despite substantial song variation between closely related species in many island cricket lineages worldwide, to date this characteristic has not received attention in the western Indian Ocean islands; existing species descriptions are based on morphology alone. Here we use a combination of acoustics and DNA sequencing to survey these islands for Ornebius crickets. We uncover a small but previously unknown radiation in the Mascarenes, constituting a three-fold increase in the Ornebius species diversity of this archipelago (from two to six species). A further new species is detected in the Comoros. Although double archipelago colonisation is the best explanation for species diversity in the Seychelles, in situ cladogenesis is the best explanation for the six species in the Mascarenes and two species of the Comoros. Whether the radiation of Mascarene Ornebius results from intra- or purely inter- island speciation cannot be determined on the basis of the phylogenetic data alone. However, the existence of genetic, song and ecological divergence at the intra-island scale is suggestive of an intra-island speciation scenario in which ecological and mating traits diverge hand-in-hand. Our results suggest that the geographic location of Ornebius radiations is partially but not fully explained by island area and isolation. A notable anomaly is Madagascar, where our surveys are consistent with existing accounts in finding no Ornebius species present. Possible explanations are discussed, invoking ecological differences between species and differences in environmental history between islands.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0148971PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4752360PMC
July 2016

SYLVAIN HUGEL (2014) Grasshoppers of the Mascarene Islands: new species and new records (Orthoptera, Caelifera). Zootaxa, 3900 (3): 399-414.

Authors:
Sylvain Hugel

Zootaxa 2015 Jan 8;3904(4):600. Epub 2015 Jan 8.

SYLVAIN HUGEL (2014) Grasshoppers of the Mascarene Islands: new species and new records (Orthoptera, Caelifera). Zootaxa, 3900 (3): 399-414.; Email: unknown.

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http://dx.doi.org/10.11646/zootaxa.3904.4.10DOI Listing
January 2015

Grasshoppers of the Mascarene Islands: new species and new records (Orthoptera, Caelifera).

Authors:
Sylvain Hugel

Zootaxa 2014 Dec 23;3900(3):399-414. Epub 2014 Dec 23.

INCI UPR3212 CNRS, Université de Strasbourg 5, rue Blaise Pascal F-67084 Strasbourg Cedexl; Email:

The grasshopper fauna of Mascarene Islands (Mauritius, Rodrigues and La Réunion), in South Western Indian ocean is examined. Numerous field surveys and examination of museum specimens recorded twenty species of Grasshoppers on the archipelago. Five of them are new records, including a new species: Odontomelus ancestrus n. sp. restricted to Round Island, a 2 km² islet North to Mauritius. Despite intensive searching, five of the non endemic species once recorded on the archipelago have not been recorded again and might correspond to temporary settlements/introductions. A key to Mascarene grasshoppers is given.
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http://dx.doi.org/10.11646/zootaxa.3900.3.4DOI Listing
December 2014

The anterior cingulate cortex is a critical hub for pain-induced depression.

Biol Psychiatry 2015 Feb 13;77(3):236-245. Epub 2014 Aug 13.

Institut des Neurosciences Cellulaires et Intégratives, Centre National de la Recherche Scientifique. Electronic address:

Background: Besides chronic stress, chronic pain is a prevalent determinant for depression. Changes induced in specific brain regions by sustained pain may alter the processing of affective information, thus resulting in anxiodepressive disorders. Here, we compared the role of the anterior cingulate cortex (ACC) and the posterior insular cortex in the anxiodepressive, sensory, and affective aspects of chronic pain.

Methods: Neuropathic pain was induced by cuffing the right sciatic nerve of C57BL/6J mice. Lesions were performed by local injection of ibotenic acid and chronic activation of the ACC by optogenetic stimulation. Anxiodepressive-related behaviors were evaluated through the novelty suppressed feeding, marble burying, splash, and forced swimming tests. Mechanical thresholds were determined using von Frey filaments, and the relief of spontaneous pain was determined by using place conditioning.

Results: The ACC lesion prevented the anxiodepressive consequences of chronic pain without affecting the sensory mechanical allodynia. Conversely, the tonic or spontaneous pain and the anxiodepressive consequences of pain remained present after posterior insular cortex lesion, even though the mechanical allodynia was suppressed. Furthermore, optogenetic stimulation of the ACC was sufficient to induce anxiety and depressive-like behaviors in naïve animals.

Conclusions: Our results show that, at cortical level, the sensory component of chronic pain remains functionally segregated from its affective and anxiodepressive components. Spontaneous tonic pain and evoked allodynia can be experimentally dissociated. Furthermore, the ACC appears as a critical hub for mood disorders, including for the anxiodepressive consequences of chronic pain, and thus constitutes an important target for divulging the underlying mechanism.
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http://dx.doi.org/10.1016/j.biopsych.2014.08.004DOI Listing
February 2015

Burrowing crickets endemic to summits in Mauritius (Orthoptera, Gryllidae): occupation of similar niches by species possibly derived from Australasian and African colonists.

Authors:
Sylvain Hugel

Zootaxa 2014 Aug 15;3852(3):382-90. Epub 2014 Aug 15.

UPR 3212 CNRS, Université de Strasbourg, 5, rue Blaise Pascal, 67084 Strasbourg cedex, France.; Email:

Two ground burrowing crickets are described from the oceanic island of Mauritius (South Western Indian Ocean): Gialaia (Eugialaia) strasbergi n. sp. belongs to a subgenus that was only known from Papua-New Guinea, and Taciturna baiderae n.sp. belongs to a genus that was only known from South Africa. Taciturna baiderae n. sp. displays a maternal care behavior to clutch of eggs and offspring. Elements of the biology of these two new species are given and their conservation status is assessed. 
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http://dx.doi.org/10.11646/zootaxa.3852.3.7DOI Listing
August 2014

Activation of transient receptor potential vanilloid 2-expressing primary afferents stimulates synaptic transmission in the deep dorsal horn of the rat spinal cord and elicits mechanical hyperalgesia.

Eur J Neurosci 2014 Oct 8;40(8):3189-201. Epub 2014 Aug 8.

Institut des Neurosciences Cellulaires et Integratives, UPR 3212 Centre National de la Recherche Scientifique, Strasbourg, France; Universite de Strasbourg, 5 rue Blaise Pascal, F-67084, Strasbourg, France.

Probenecid, an agonist of transient receptor vanilloid (TRPV) type 2, was used to evaluate the effects of TRPV2 activation on excitatory and inhibitory synaptic transmission in the dorsal horn (DH) of the rat spinal cord and on nociceptive reflexes induced by thermal heat and mechanical stimuli. The effects of probenecid were compared with those of capsaicin, a TRPV1 agonist. Calcium imaging experiments on rat dorsal root ganglion (DRG) and DH cultures indicated that functional TRPV2 and TRPV1 were expressed by essentially non-overlapping subpopulations of DRG neurons, but were absent from DH neurons and DH and DRG glial cells. Pretreatment of DRG cultures with small interfering RNAs against TRPV2 suppressed the responses to probenecid. Patch-clamp recordings from spinal cord slices showed that probenecid and capsaicin increased the frequencies of spontaneous excitatory postsynaptic currents (sEPSCs) and spontaneous inhibitory postsynaptic currents in a subset of laminae III-V neurons. In contrast to capsaicin, probenecid failed to stimulate synaptic transmission in lamina II. Intrathecal or intraplantar injections of probenecid induced mechanical hyperalgesia/allodynia without affecting nociceptive heat responses. Capsaicin induced both mechanical hyperalgesia/allodynia and heat hyperalgesia. Activation of TRPV1 or TRPV2 in distinct sets of primary afferents increased the sEPSC frequencies in a largely common population of DH neurons in laminae III-V, and might underlie the development of mechanical hypersensitivity following probenecid or capsaicin treatment. However, only TRPV1-expressing afferents facilitated excitatory and/or inhibitory transmission in a subpopulation of lamina II neurons, and this phenomenon might be correlated with the induction of thermal heat hyperalgesia.
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http://dx.doi.org/10.1111/ejn.12688DOI Listing
October 2014

True katydids (Pseudophyllinae) from Guadeloupe: acoustic signals and functional considerations of song production.

J Insect Sci 2013 ;13:157

1 Georg-August-University of Göttingen, Dept. of Cellular Neurobiology, JFB-Institute of Zoology and Anthropology, Schwann-Schleiden-Centre for molecular cell biology, Julia-Lermontowa-Weg 3, 37077 Göttingen, Germany.

Guadeloupe, the largest of the Leeward Islands, harbors three species of Pseudophyllinae (Orthoptera: Tettigoniidae) belonging to distinct tribes. This study examined the basic aspects of sound production and acousto-vibratory behavior of these species. As the songs of many Pseudophyllinae are complex and peak at high frequencies, they require high quality recordings. Wild specimens were therefore recorded ex situ. Collected specimens were used in structure-function experiments. Karukerana aguilari Bonfils (Pterophyllini) is a large species with a mirror in each tegmen and conspicuous folds over the mirror. It sings 4-6 syllables, each comprising 10-20 pulses, with several peaks in the frequency spectrum between 4 and 20 kHz. The song is among the loudest in Orthoptera (> 125 dB SPL in 10 cm distance). The folds are protective and have no function in song production. Both mirrors may work independently in sound radiation. Nesonotus reticulatus (Fabricius) (Cocconotini) produces verses from two syllables at irregular intervals. The song peaks around 20 kHz. While singing, the males often produce a tremulation signal with the abdomen at about 8-10 Hz. To our knowledge, it is the first record of simultaneous calling song and tremulation in Orthoptera. Other males reply to the tremulation with their own tremulation. Xerophyllopteryx fumosa (Brunner von Wattenwyl) (Pleminiini) is a large, bark-like species, producing a syllable of around 20 pulses. The syllables are produced with irregular rhythms (often two with shorter intervals). The song peaks around 2-3 kHz and 10 kHz. The hind wings are relatively thick and are held between the half opened tegmina during singing. Removal of the hind wings reduces song intensity by about 5 dB, especially of the low frequency component, suggesting that the hind wings have a role in amplifying the song.
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http://dx.doi.org/10.1673/031.013.15701DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4015413PMC
January 2015

Antidepressants suppress neuropathic pain by a peripheral β2-adrenoceptor mediated anti-TNFα mechanism.

Neurobiol Dis 2013 Dec 23;60:39-50. Epub 2013 Aug 23.

Institut des Neurosciences Cellulaires et Intégratives, Centre National de la Recherche Scientifique, 67084 Strasbourg, France; Université de Strasbourg, 67084 Strasbourg, France.

Neuropathic pain is pain arising as a direct consequence of a lesion or disease affecting the somatosensory system. It is usually chronic and challenging to treat. Some antidepressants are first-line pharmacological treatments for neuropathic pain. The noradrenaline that is recruited by the action of the antidepressants on reuptake transporters has been proposed to act through β2-adrenoceptors (β2-ARs) to lead to the observed therapeutic effect. However, the complex downstream mechanism mediating this action remained to be identified. In this study, we demonstrate in a mouse model of neuropathic pain that an antidepressant's effect on neuropathic allodynia involves the peripheral nervous system and the inhibition of cytokine tumor necrosis factor α (TNFα) production. The antiallodynic action of nortriptyline is indeed lost after peripheral sympathectomy, but not after lesion of central descending noradrenergic pathways. More particularly, we report that antidepressant-recruited noradrenaline acts, within dorsal root ganglia, on β2-ARs expressed by non-neuronal satellite cells. This stimulation of β2-ARs decreases the neuropathy-induced production of membrane-bound TNFα, resulting in relief of neuropathic allodynia. This indirect anti-TNFα action was observed with the tricyclic antidepressant nortriptyline, the selective serotonin and noradrenaline reuptake inhibitor venlafaxine and the β2-AR agonist terbutaline. Our data revealed an original therapeutic mechanism that may open novel research avenues for the management of painful peripheral neuropathies.
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http://dx.doi.org/10.1016/j.nbd.2013.08.012DOI Listing
December 2013

New pseudophyllinae from the Lesser Antilles (Orthoptera: Ensifera: Tettigoniidae).

Zootaxa 2013 Nov 27;3741:279-88. Epub 2013 Nov 27.

Muséum national d'Histoire naturelle, Département systématique et évolution, UMR 7205 CNRS, Case postale 50 (Entomologie), 57 rue Cuvier, F-75231 Paris cedex 05, France; Email:

Two new Cocconitini Brunner von Wattenwyl, 1895 species belonging to Nesonotus Beier, 1960 are described from the Lesser Antilles: Nesonotus caeruloglobus Hugel, n. sp. from Dominica, and Nesonotus vulneratus Hugel, n. sp. from Martinique. The songs of both species are described and elements of biology are given. The taxonomic status of species close to Nesonotus tricornis (Thunberg, 1815) is discussed.
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http://dx.doi.org/10.11646/zootaxa.3741.2.6DOI Listing
November 2013

Neurotensin inhibits background K+ channels and facilitates glutamatergic transmission in rat spinal cord dorsal horn.

Eur J Neurosci 2011 Oct 21;34(8):1230-40. Epub 2011 Sep 21.

Institut des Neurosciences Cellulaires et Intégratives, Centre National de la Recherche Scientifique, Université de Strasbourg, 21 rue René Descartes, Strasbourg, France.

Neurotensin (NT) is a neuropeptide involved in the modulation of nociception. We have investigated the actions of NT on cultured postnatal rat spinal cord dorsal horn (DH) neurons. NT induced an inward current associated with a decrease in membrane conductance in 46% of the neurons and increased the frequency of glutamatergic miniature excitatory synaptic currents in 37% of the neurons. Similar effects were observed in acute slices. Both effects of NT were reproduced by the selective NTS1 agonist JMV449 and blocked by the NTS1 antagonist SR48692 and the NTS1/NTS2 antagonist SR142948A. The NTS2 agonist levocabastine had no effect. The actions of NT persisted after inactivation of G(i/o) proteins by pertussis toxin but were absent after inactivation of protein kinase C (PKC) by chelerythrine or inhibition of the MAPK (ERK1/2) pathway by PD98059. Pre- and postsynaptic effects of NT were insensitive to classical voltage- and Ca(2+) -dependent K(+) channel blockers. The K(+) conductance inhibited by NT was blocked by Ba(2+) and displayed no or little inward rectification, despite the presence of strongly rectifying Ba(2+) -sensitive K(+) conductance in these neurons. This suggested that NT blocked two-pore domain (K2P) background K(+) -channels rather than inwardly rectifying K(+) channels. Zn(2+) ions, which inhibit TRESK and TASK-3 K2P channels, decreased NT-induced current. Our results indicate that in DH neurons NT activates NTS1 receptors which, via the PKC-dependent activation of the MAPK (ERK1/2) pathway, depolarize the postsynaptic neuron and increase the synaptic release of glutamate. These actions of NT might modulate the transfer and the integration of somatosensory information in the DH.
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http://dx.doi.org/10.1111/j.1460-9568.2011.07846.xDOI Listing
October 2011
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