Publications by authors named "Xin-Cheng Zhao"

24 Publications

  • Page 1 of 1

Antennal Lobe Atlas of an Emerging Corn Pest, .

Front Neuroanat 2020 28;14:23. Epub 2020 May 28.

State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.

Moths develop sophisticated olfactory systems to sense the airborne chemical cues from the environment. Understanding the structural basis in the neuronal center is a fundamental neuroethological step. Little is known about the emerging crop pest with regard to its morphology or its neuronal organizations. Through antibody staining and digital 3D modeling, we re-constructed the primary olfactory center-the antennal lobe of . In the antennal lobes 68.8 ± 3.1 male glomeruli and 70.8 ± 1.0 female glomeruli were identified with obvious sexual dimorphism. In particular, male adults of contain a macroglomerular complex (MGC) that consists of three subunits, while the female lobe has four relatively enlarged glomeruli at the entrance of the antennal nerve. Glomeruli were later clustered with deviation and variance, and referring to reported olfactory related receptor family genes in seven different moth species, we found that glomerular counts of these insects are better related to the sum of odorant receptor and ionotropic receptor numbers, suggesting olfactory receptors and ionotropic receptors may both involved in olfaction of Noctuidae moths.
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http://dx.doi.org/10.3389/fnana.2020.00023DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7271962PMC
May 2020

Revisiting the Labial Pit Organ Pathway in the Noctuid Moth, .

Front Physiol 2020 17;11:202. Epub 2020 Mar 17.

Chemosensory Laboratory, Department of Psychology, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.

Lepidopteran species detect CO via a specialized organ located on the peripheral segment of the labial palps, the labial palp pit organ (LPO). Based on tracing of LPO sensory neurons targeting one distinct antennal-lobe glomerulus, Kent and her colleagues described the projections originating from the LPO in the sphinx moth as "" already in the 1980 ties. In spite of similar reports from studies of other lepidopteran species, however, it has been an unresolved issue whether additional termination areas of the labial nerve, such as the gnathal ganglion (GNG) and the ventral nerve cord, are actually output sites of LPO neurons. Since the previous studies have interpreted slightly differently about the projection pattern occurring from the classical mass staining, we performed selective mass staining from the inside of the pit and from the outer surface of the peripheral palp. The results demonstrated that the LPO sensory neurons project exclusively to the LPO glomerulus (LPOG), whereas the non-LPO sensory neurons target the GNG and the ventral nerve cord. Additional iontophoretic staining of individual LPO sensory neurons, performed from the LPO and the LPOG, showed three morphological neuron types: one bilateral targeting the LPOG in both antennal lobes, one unilateral targeting the ipsilateral LPOG only, and one contralateral targeting the LPOG in the other antennal lobe. Finally, to explore putative differences in the projection pattern of neurons housed by two previously reported sensillum types in the pit, i.e., hair-shaped sensilla located distally and club-shaped sensilla located proximally, we performed mass staining from two different levels of the peripheral palp. We found a projection pattern implying stronger innervation of the ipsi- than the contralateral LPOG in both staining experiments.
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http://dx.doi.org/10.3389/fphys.2020.00202DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7090773PMC
March 2020

Brain Organization of : A Hemipteran Species With Prominent Antennal Lobes.

Front Neuroanat 2019 17;13:70. Epub 2019 Jul 17.

Department of Entomology, College of Plant Protection, Henan Agricultural University, Zhengzhou, China.

The anatomical organization of distinct regions in the insect brain often reflects their functions. In the present study, the brain structure of was examined by using immunolabeling and three-dimensional reconstruction. The results revealed the location and volume of prominent neuropils, such as the antennal lobes (AL), optic lobes (OL), anterior optic tubercles (AOTU), central body (CB), lateral accessory lobes (LAL), mushroom lobes, and distinct tritocerebral neuropils. As expected, this brain is similar to that of other insects. One exception, however, is that the antennal lobes were found to be the most prominent neuropils. Their size relative to the entire brain is the largest among all insect species studied so far. In contrast, the calyx, a region getting direct input from the antennal lobe, has a smaller size relative to the brain than that of other species. These findings may suggest that olfaction plays an essential role for .
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http://dx.doi.org/10.3389/fnana.2019.00070DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6654032PMC
July 2019

Distribution of Serotonin-Immunoreactive Neurons in the Brain and Gnathal Ganglion of Caterpillar .

Front Neuroanat 2019 28;13:56. Epub 2019 May 28.

Department of Entomology, College of Plant Protection, Henan Agricultural University, Zhengzhou, China.

Serotonin (5-hydroxytryptamine, 5-HT) is an important biogenic amine that acts as a neural circuit modulator. It is widespread in the central nervous system of insects. However, little is known about the distribution of serotonin in the nervous system of the cotton bollworm . In the present study, we performed immunohistochemical experiments with anti-serotonin serum to examine the distribution of serotonin in the central nervous system of larvae. We found about 40 serotonin-immunoreactive neurons in the brain and about 20 in the gnathal ganglion. Most of these neurons are wide-field neurons giving rise to processes throughout the neuropils of the brain and the gnathal ganglion. In the central brain, serotonin-immunoreactive processes are present bilaterally in the tritocerebrum, the deutocerebrum, and major regions of the protocerebrum, including the central body (CB), lateral accessory lobes (LALs), clamps, crepine, superior protocerebrum, and lateral protocerebrum. The CB, anterior ventrolateral protocerebrum (AVLP), and posterior optic tubercle (POTU) contain extensive serotonin-immunoreactive process terminals. However, the regions of mushroom bodies, the lateral horn, and protocerebral bridges (PBs) are devoid of serotonin-immunoreactivity. In the gnathal ganglion, the serotonin-immunoreactive processes are also widespread throughout the neuropil, and some process projections extend to the tritocerebrum. Our results provide the first comprehensive description of the serotonergic neuronal network in larvae, and they reveal the neural architecture and the distribution of neural substances, allowing us to explore the neural mechanisms of behaviors by using electrophysiological and pharmacological approaches on the target regions.
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http://dx.doi.org/10.3389/fnana.2019.00056DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6547022PMC
May 2019

CNOT1 is involved in TTP‑mediated ICAM‑1 and IL‑8 mRNA decay.

Mol Med Rep 2018 Aug 22;18(2):2321-2327. Epub 2018 Jun 22.

Department of Respiratory and Critical Care Medicine, Jinling Hospital, Nanjing, Jiangsu 210002, P.R. China.

Subunit 1 is the scaffold protein of the carbon catabolite repressor protein 4 (CCR4)‑negative on TATA (NOT) complex (CNOT1). In our previous study, it was reported that tristetraprolin (TTP) could recruit subunit 7 of the CCR4‑NOT complex (CNOT7) to induce the degradation of intercellular adhesion molecule‑1 (ICAM‑1) and interleukin‑8 (IL‑8) mRNA in human pulmonary microvascular endothelial cells (HPMECs). It was additionally demonstrated that TTP, CNOT7 and CNOT1 formed a complex in HPMECs. However, whether CNOT1 is involved in TTP‑mediated ICAM‑1 and IL‑8 mRNA decay remains unclear. The present study demonstrated that CNOT1 knockdown improved ICAM‑1 and IL‑8 mRNA stabilization and protein expression levels. The immunofluorescence results demonstrated that CNOT1, CNOT7 and TTP are co‑localized in the cytoplasm. CNOT1 silencing abolished CNOT7 and TTP coimmunoprecipitation. However, CNOT7 silencing did not influence CNOT1 and TTP coimmunoprecipitation, and TTP silencing additionally did not influence CNOT1 and CNOT7 coimmunoprecipitation. These results together with the authors' previous study, have identified that CNOT1 provides a platform for the recruitment of TTP and CNOT7, and is involved in TTP‑mediated ICAM‑1 and IL‑8 mRNA decay.
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http://dx.doi.org/10.3892/mmr.2018.9213DOI Listing
August 2018

Higher plasticity in feeding preference of a generalist than a specialist: experiments with two closely related Helicoverpa species.

Sci Rep 2017 12 19;7(1):17876. Epub 2017 Dec 19.

Laboratory of Entomology, Wageningen University, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands.

Herbivorous insects have been categorized as generalists or specialists depending on the taxonomic relatedness of the plants they use as food or oviposition substrates. The plasticity in host plant selection behavior of species belonging to the two categories received little attention. In the present work, fifth instar caterpillars of the generalist herbivore Helicoverpa armigera and its closely related species, the specialist Helicoverpa assulta, were fed on common host plants or artificial diet, after which their feeding preference was assessed individually by using dual - and triple- plant choice assays. Results show both the two Helicoverpa species have a preference hierarchy for host plants. Compared to the fixed preference hierarchy of the specialist H. assulta, the generalist H. armigera exhibited extensive plasticity in feeding preference depending on the host plant experienced during larval development. Whereas the specialist H. assulta exhibited a rigid preference in both dual and triple-plant choice assays, our findings demonstrate that the generalist H. armigera expressed stronger preferences in the dual-plant choice assay than in the triple-plant choice assay. Our results provide additional evidence supporting the neural constraints hypothesis which predicts that generalist herbivores make less accurate decisions than specialists when selecting plants.
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http://dx.doi.org/10.1038/s41598-017-18244-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5736596PMC
December 2017

Central Projections of Antennal and Labial Palp Sensory Neurons in the Migratory Armyworm .

Front Cell Neurosci 2017 21;11:370. Epub 2017 Nov 21.

State Key Laboratory for Biology of Plant Disease and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.

The oriental armyworm, (Walker), is a polyphagous, migratory pest relying on olfactory cues to find mates, locate nectar, and guide long-distance flight behavior. In the present study, a combination of neuroanatomical techniques were utilized on this species, including backfills, confocal microscopy, and three-dimensional reconstructions, to trace the central projections of sensory neurons from the antenna and the labial pit organ, respectively. As previously shown, the axons of the labial sensory neurons project via the ipsilateral labial nerve and terminate in three main areas of the central nervous system: (1) the labial-palp pit organ glomerulus of each antennal lobe, (2) the gnathal ganglion, and (3) the prothoracic ganglion of the ventral nerve cord. Similarly, the antennal sensory axons project to multiple areas of the central nervous system. The ipsilateral antennal nerve targets mainly the antennal lobe, the antennal mechanosensory and motor center, and the prothoracic and mesothoracic ganglia. Specific staining experiments including dye application to each of the three antennal segments indicate that the antennal lobe receives input from flagellar olfactory neurons exclusively, while the antennal mechanosensory and motor center is innervated by mechanosensory neurons from the whole antenna, comprising the flagellum, pedicle, and scape. The terminals in the mechanosensory and motor center are organized in segregated zones relating to the origin of neurons. The flagellar mechanosensory axons target anterior zones, while the pedicular and scapal axons terminate in posterior zones. In the ventral nerve cord, the processes from the antennal sensory neurons terminate in the motor area of the thoracic ganglia, suggesting a close connection with motor neurons. Taken together, the numerous neuropils innervated by axons both from the antenna and labial palp indicate the multiple roles these sensory organs serve in insect behavior.
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http://dx.doi.org/10.3389/fncel.2017.00370DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5702295PMC
November 2017

Distribution of tachykinin-related peptides in the brain of the tobacco budworm Heliothis virescens.

J Comp Neurol 2017 Dec 15;525(18):3918-3934. Epub 2017 Sep 15.

Department of Biology, Animal Physiology, Philipps University, Marburg, 35032, Germany.

Invertebrate tachykinin-related peptides (TKRPs) comprise a group of signaling molecules having sequence similarities to mammalian tachykinins. A growing body of evidence has demonstrated the presence of TKRPs in the central nervous system of insects. In this investigation, we used an antiserum against locustatachykinin-II to reveal the distribution pattern of these peptides in the brain of the moth Heliothis virescens. Immunolabeling was found throughout the brain of the heliothine moth. Most of the roughly 500 locustatachykinin-II immunoreactive cell bodies, that is, ca. 400, were located in the protocerebrum, whereas the rest was distributed in the deutocerebrum, tritocerebrum, and the gnathal ganglion. Abundant immunoreactive processes were located in the same regions. Labeled processes in the protocerebrum were especially localized in optic lobe, central body, lateral accessory lobe, superior protocerebrum, and lateral protocerebrum, while those in the deutocerebrum were present exclusively in the antennal lobe. In addition to brain interneurons, four pairs of median neurosecretory cells in the pars intercerebralis with terminal processes in the corpora cardiaca and aorta wall were immunostained. No sexual dimorphism in immunoreactivity was found. Comparing the data obtained here with findings from other insect species reveals considerable differences, suggesting species-specific roles of tachykinin-related peptides in insects.
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http://dx.doi.org/10.1002/cne.24310DOI Listing
December 2017

The Inheritance of the Pheromone Sensory System in Two Species: Dominance of and Possible Introgression from .

Front Cell Neurosci 2016 10;10:302. Epub 2017 Jan 10.

State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of SciencesBeijing, China; College of Life Sciences, University of Chinese Academy of SciencesBeijing, China.

Hybridization of sympatric closely related species may sometimes lead to introgression and speciation. The sister species and both use (Z)-11-hexadecenal and (Z)-9-hexadecenal as sex pheromone components but in reversed ratios. Female and male could hybridize and produce fertile male hybrids, which can then backcross with females of the two parent species to get backcross lines in the laboratory. In this study, we compared the olfactory responses to pheromone compounds in the periphery and in the antennal lobes (ALs) of males of the two species, as well as of their hybrids and backcrosses. Single-sensillum recordings were carried out to explore characteristics of male-specific sensilla on the antennae, and calcium imaging combined with digital 3D-reconstruction was used to describe what happens in the macroglomerular complex (MGC) of the AL. The results show that the population ratio of the two male-specific types of olfactory sensory neurons responding to two sex pheromone components are controlled by a major gene, and that the allele of is dominant. Consistently, the study of the representative areas activated by sex pheromone components in the ALs further support the dominance of . However, the topological structure of the MGC in the hybrid was similar but not identical to that in . All subtypes of male-specific sensilla identified in the two species were found in the male hybrids and backcrosses. Moreover, two new subtypes with broader response spectra (the expanded A subtype and the expanded C subtype) emerged in the hybrids. Based on the inheritance pattern of the pheromone sensory system, we predict that when hybridization of female and male occurs in the field, male hybrids would readily backcross with female , and introgression might occur from into through repeated backcrossing.
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http://dx.doi.org/10.3389/fncel.2016.00302DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5222888PMC
January 2017

A global-wide search for sexual dimorphism of glomeruli in the antennal lobe of female and male Helicoverpa armigera.

Sci Rep 2016 10 11;6:35204. Epub 2016 Oct 11.

Department of Entomology, College of Plant Protection, Henan Agricultural University, Zhengzhou, 450002, China.

By using immunostaining and three-dimensional reconstruction, the anatomical organization of the antennal lobe glomeruli of the female cotton bollworm Helicoverpa armigera was investigated. Eighty-one glomeruli were identified, 15 of which were not previously discovered. The general anatomical organization of the AL of female is similar to that of male and all glomeruli were classified into four sub-groups, including the female-specific glomerular complex, posterior complex, labial-palp pit organ glomerulus, and ordinary glomeruli. A global-wide comparison on the complete glomerular map of female and male was performed and for the first time the quantitative difference in volume for each individual homologous glomerulus was analyzed. We found that the sexual dimorphism includes not only the sex-specific glomeruli but also some of the other glomeruli. The findings in the present study may provide a reference to examine the antennal-lobe organization more in detail and to identify new glomeruli in other moth species. In addition, the complete identification and global-wide comparison of the sexes provide an important basis for mapping the function of distinct glomeruli and for understanding neural mechanisms underlying sexually dimorphic olfactory behaviors.
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http://dx.doi.org/10.1038/srep35204DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5057091PMC
October 2016

Central Projection of Antennal Sensory Neurons in the Central Nervous System of the Mirid Bug Apolygus lucorum (Meyer-Dür).

PLoS One 2016 1;11(8):e0160161. Epub 2016 Aug 1.

Department of Pomology, College of Horticulture, Henan Agricultural University, Zhengzhou, 450002, China.

The mirid bug Apolygus lucorum (Meyer-Dür), a polyphagous pest, is dependent on olfactory cues to locate various host plant species and mates. In this study, we traced the projection pathway of the antennal sensory neurons and visualized their projection patterns in the central nervous system of A. lucorum through confocal microscopy and digital reconstructions. We also examined the glomerular organization of the primary olfactory center of the brain, the antennal lobe, and created a three-dimensional model of the glomeruli. We found that the axons of the sensory neurons project into the brain via the ipsilateral antennal nerve, and descend further into the gnathal ganglion, prothoracic ganglion, mesothoracic ganglion, and metathoracic ganglion, and reach as far as to the abdominal ganglion. Such a projection pattern indicates that antennal sensory neurons of A. lucorum may be potentially directly connected to motor neurons. The antennal lobe, however, is the major target area of antennal sensory neurons. The antennal lobe is composed of a large number of glomeruli, i.e. 70-80 glomeruli in one AL of A. lucorum. The results of this study which provide information about the basic anatomical arrangement of the brain olfactory center of A. lucorum, are important for further investigations of chemosensory encoding mechanisms of the mirid bug.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0160161PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4968828PMC
August 2017

Glomerular identification in the antennal lobe of the male moth Helicoverpa armigera.

J Comp Neurol 2016 10 3;524(15):2993-3013. Epub 2016 May 3.

Department of Psychology, Norwegian University of Science and Technology, Trondheim, 7489, Norway.

This study investigates anatomical organization of the antennal lobe (AL) glomeruli of the male cotton bollworm Helicoverpa armigera by synaptic antibody staining combined with three-dimensional reconstruction. To identify all glomeruli, their boundaries were accurately determined by means of several additional staining techniques visualizing the neuron categories forming the characteristic spherical neuropils. In total, 78-80 glomeruli were identified in the male H. armigera. The number of glomeruli was considerably larger than that previously reported in this species. Thus, compared with previous studies, we identified 15 new glomeruli, G63-G77. Most of them are located in the posterior part of the AL, which was previously considered to be a part of the protocerebrum. From the general anatomical organization of the AL glomeruli of H. armigera, we classified these neuropil structures into four groups, the macroglomerular complex, posterior complex, labial-palp pit organ glomerulus, and ordinary glomeruli. The complete identification of glomeruli is important for future studies seeking to explore further the coding mechanisms residing within the primary olfactory center of the moth brain. J. Comp. Neurol. 524:2993-3013, 2016. © 2016 Wiley Periodicals, Inc.
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http://dx.doi.org/10.1002/cne.24003DOI Listing
October 2016

Characteristics of morphology, electrophysiology, and central projections of two sensilla styloconica in Helicoverpa assulta larvae.

Neuroreport 2015 Aug;26(12):703-11

Department of Entomology, College of Plant Protection, Henan Agricultural University, Zhengzhou, Henan, China.

The medial and lateral styloconic sensilla, constituting the main taste organs of lepidopterous caterpillars, were investigated in the oligophagous species, Helicoverpa assulta (Guenée) (Lepidoptera: Noctuidae). In this paper, the two sensilla were morphologically and physiologically characterized by scanning electron microscopy and tip recordings, respectively. The central projections of their respective sensory neurons were mapped by anterograde staining experiments combined with confocal laser scanning microscopy. The results showed that the two sensilla are in general morphologically similar. However, the size of the peg on the medial sensillum is significantly greater than that of the lateral. Tobacco leaf saps, sinigrin, and nicotine elicited strong responses from neurons housed by the medial sensillum, whereas sucrose activated primarily the lateral sensillum. All stained neurons in either sensillum showed a projection pattern involving axons entering the subesophageal ganglion through the ipsilateral maxillary and passing further on through the ipsilateral circumesophageal connective to the tritocerebrum of the brain. In the subesophageal ganglion, the axons targeted two areas: the ventrolateral section and the region near the neuromere midline. One distinction between the staining patterns originating from the two sensilla, however, is that axons arising from the medial sensillum, and not the lateral, give off some additional neural branches in the subesophageal ganglion including a few arborizations surrounding a tract, plus a long process extending posteriorly along the midline. Differences in the central projections derived from the two sensilla styloconica have not been reported previously.
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http://dx.doi.org/10.1097/WNR.0000000000000413DOI Listing
August 2015

Representation of pheromones, interspecific signals, and plant odors in higher olfactory centers; mapping physiologically identified antennal-lobe projection neurons in the male heliothine moth.

Front Syst Neurosci 2014 9;8:186. Epub 2014 Oct 9.

Department of Psychology, Norwegian University of Science and Technology (NTNU) Trondheim, Norway.

The arrangement of anatomically separated systems for information about general and pheromone odorants is well documented at the initial levels of the olfactory pathway both in vertebrates and insects. In the primary olfactory center of the moth brain, for example, a few enlarged glomeruli situated dorsally, at the entrance of the antennal nerve, are devoted to information about female-produced substances whereas a set of more numerous ordinary glomeruli (OG) receives input about general odorants. Heliothine moths are particularly suitable for studying central chemosensory mechanisms not only because of their anatomically separated systems for plant odors and pheromones but also due to their use of female-produced substances in communication across the species. Thus, the male-specific system of heliothine moths includes two sub-arrangements, one ensuring attraction and mating behavior by carrying information about pheromones released by conspecifics, and the other inhibition of attraction via signal information emitted from heterospecifics. Based on previous tracing experiments, a general chemotopic organization of the male-specific glomeruli has been demonstrated in a number of heliothine species. As compared to the well explored organization of the moth antennal lobe (AL), demonstrating a non-overlapping representation of the biologically relevant stimuli, less is known about the neural arrangement residing at the following synaptic level, i.e., the mushroom body calyces and the lateral horn. In the study presented here, we have labeled physiologically characterized antennal-lobe projection neurons in males of the two heliothine species, Heliothis virescens and Helicoverpa assulta, for the purpose of mapping their target regions in the protocerebrum. In order to compare the representation of plant odors, pheromones, and interspecific signals in the higher brain regions of each species, we have created standard brain atlases and registered three-dimensional models of distinct uniglomerular projection neuron types into the relevant atlas.
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http://dx.doi.org/10.3389/fnsys.2014.00186DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4191081PMC
October 2014

Central projections of gustatory receptor neurons in the medial and the lateral sensilla styloconica of Helicoverpa armigera larvae.

PLoS One 2014 16;9(4):e95401. Epub 2014 Apr 16.

Department of Entomology, College of Plant Protection, Henan Agricultural University, Zhengzhou, Henan, China.

Food selection behavior of lepidopteran larvae is predominantly governed by the activation of taste neurons present in two sensilla styloconica located on the galea of the maxilla. In this study, we present the ultrastructure of the sensilla styloconica and the central projection pattern of their associated receptor neurons in larvae of the heliothine moth, Helicoverpa armigera. By means of light microscopy and scanning electron microscopy, the previous findings of two morphologically fairly similar sensilla comprising a socketed conic tip inserted into a large peg were confirmed. However, the peg size of the medial sensillum was found to be significantly bigger than that of the lateral sensillum. The sensory neurons derived from each sensillum styloconicum were mapped separately using anterograde staining experiments combined with confocal laser-scanning microscopy. For determining the afferents' target regions relative to each other, we reconstructed the labeled axons and placed them into a common reference framework. The sensory axons from both sensilla projected via the ipsilateral maxillary nerve to the suboesophageal ganglion and further through the ipsilateral circumoesophageal connective to the brain. In the suboesophageal ganglion, the sensory projections targeted two areas of the ipsilateral maxillary neuropil, one located in the ventrolateral neuromere and the other adjacent to the neuromere midline. In the brain, the axon terminals targeted the dorso-anterior area of the ipsilateral tritocerebrum. As confirmed by the three-dimensional reconstructions, the target regions of the neural projections originating from each of the two sensilla styloconica were identical.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0095401PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3989337PMC
June 2015

Processing of Pheromone Information in Related Species of Heliothine Moths.

Insects 2014 Oct 14;5(4):742-61. Epub 2014 Oct 14.

State Key Laboratory for Biology of Plant Disease and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.

In heliothine moths, the male-specific olfactory system is activated by a few odor molecules, each of which is associated with an easily identifiable glomerulus in the primary olfactory center of the brain. This arrangement is linked to two well-defined behavioral responses, one ensuring attraction and mating behavior by carrying information about pheromones released by conspecific females and the other inhibition of attraction via signal information emitted from heterospecifics. The chance of comparing the characteristic properties of pheromone receptor proteins, male-specific sensory neurons and macroglomerular complex (MGC)-units in closely-related species is especially intriguing. Here, we review studies on the male-specific olfactory system of heliothine moths with particular emphasis on five closely related species, i.e., Heliothis virescens, Heliothis subflexa, Helicoverpa zea, Helicoverpa assulta and Helicoverpa armigera.
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http://dx.doi.org/10.3390/insects5040742DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4592608PMC
October 2014

Sound-sensitive neurons innervate the ventro-lateral protocerebrum of the heliothine moth brain.

Cell Tissue Res 2014 Feb 10;355(2):289-302. Epub 2013 Dec 10.

Department of Psychology/Neuroscience Unit, MTFS, Norwegian University of Science and Technology (NTNU), 7489, Trondheim, Norway,

Many noctuid moth species perceive ultrasound via tympanic ears that are located at the metathorax. Whereas the neural processing of auditory information is well studied at the peripheral and first synaptic level, little is known about the features characterizing higher order sound-sensitive neurons in the moth brain. During intracellular recordings from the lateral protocerebrum in the brain of three noctuid moth species, Heliothis virescens, Helicoverpa armigera and Helicoverpa assulta, we found an assembly of neurons responding to transient sound pulses of broad bandwidth. The majority of the auditory neurons ascended from the ventral cord and ramified densely within the anterior region of the ventro-lateral protocerebrum. The physiological and morphological characteristics of these auditory neurons were similar. We detected one additional sound-sensitive neuron, a brain interneuron with its soma positioned near the calyces of mushroom bodies and with numerous neuronal processes in the ventro-lateral protocerebrum. Mass-staining of ventral-cord neurons supported the assumption that the ventro-lateral region of the moth brain was the main target for the auditory projections ascending from the ventral cord.
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http://dx.doi.org/10.1007/s00441-013-1749-9DOI Listing
February 2014

Fine structure and primary sensory projections of sensilla located in the labial-palp pit organ of Helicoverpa armigera (Insecta).

Cell Tissue Res 2013 Sep 5;353(3):399-408. Epub 2013 Jun 5.

Department of Entomology, College of Plant Protection, Henan Agricultural University, Zhengzhou, Henan, 450002, China.

The fine structure and primary sensory projections of sensilla located in the labial-palp pit organ of the cotton bollworm Helicoverpa armigera (Insecta, Lepidoptera) are investigated by scanning electron and transmission electron microscopy combined with confocal laser scanning microscopy. The pit organ located on the third segment of the labial palp is about 300 μm deep with a 60-μm-wide opening, each structure containing about 1200 sensilla. Two sensillum types have been found, namely hair-shaped and club-shaped sensilla, located on the upper and lower half of the pit, respectively. Most sensilla possess a single dendrite. The dendrite housed by the club-shaped sensilla is often split into several branches or becomes lamellated in the outer segment. As reported previously, the sensory axons of the sensilla in the labial pit organ form a bundle entering the ipsilateral side of the subesophageal ganglion via the labial palp nerve and project to three distinct areas: the labial pit organ glomerulus in each antennal lobe, the subesophageal ganglion and the ventral nerve cord. In the antennal lobe, the labial pit organ glomerulus is innervated by sensory axons from the labial pit organ only; no antennal afferents target this unit. One neuron has been found extending fine processes into the subesophageal ganglion and innervating the labial palp via one branch passing at the base of the labial palp nerve. The soma of this assumed motor neuron is located in the ipsilateral cell body layer of the subesophageal ganglion. Our results provide valuable knowledge concerning the neural circuit encoding information about carbon dioxide and should stimulate further investigations directed at controlling pest species such as H. armigera.
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http://dx.doi.org/10.1007/s00441-013-1657-zDOI Listing
September 2013

A multisensory centrifugal neuron in the olfactory pathway of heliothine moths.

J Comp Neurol 2013 Jan;521(1):152-68

Department of Psychology, Neuroscience Unit, Norwegian University of Science and Technology, 7491 Trondheim, Norway.

We have characterized, by intracellular recording and staining, a unique type of centrifugal neuron in the brain olfactory center of two heliothine moth species; one in Heliothis virescens and one in Helicoverpa armigera. This unilateral neuron, which is not previously described in any moth, has fine processes in the dorsomedial region of the protocerebrum and extensive neuronal branches with blebby terminals in all glomeruli of the antennal lobe. Its soma is located dorsally of the central body close to the brain midline. Mass-fills of antennal-lobe connections with protocerebral regions showed that the centrifugal neuron is, in each brain hemisphere, one within a small group of neurons having their somata clustered. In both species the neuron was excited during application of non-odorant airborne signals, including transient sound pulses of broad bandwidth and air velocity changes. Additional responses to odors were recorded from the neuron in Heliothis virescens. The putative biological significance of the centrifugal antennal-lobe neuron is discussed with regard to its morphological and physiological properties. In particular, a possible role in multisensory processes underlying the moth's ability to adapt its odor-guided behaviors according to the sound of an echo-locating bat is considered.
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http://dx.doi.org/10.1002/cne.23166DOI Listing
January 2013

Arrangement of output information from the 3 macroglomerular units in the heliothine moth Helicoverpa assulta: morphological and physiological features of male-specific projection neurons.

Chem Senses 2010 Jul 9;35(6):511-21. Epub 2010 May 9.

Department of Psychology and Neuroscience Unit, MTFS, Norwegian University of Science and Technology, Olav Kyrres gate 9, Trondheim, Norway.

Helicoverpa assulta is exceptional among heliothine species studied so far as concerns composition of the pheromone blend. Previous reports have accordingly pointed out distinct characteristics in the male-specific olfactory pathway of this species, peripherally by an unusual distribution of 2 sensillum categories and centrally by a particular anatomical arrangement of the male-specific glomeruli constituting the macroglomerular complex (MGC). In order to determine the physiological tuning of the 3 MGC units in this species, we have characterized male-specific antennal-lobe projection neurons morphologically and physiologically by use of the intracellular recording and staining technique combined with confocal microscopy. The results show 2 projection neuron types of equal numbers, one that responds to the primary pheromone component, cis-9-hexadecenal, and arborizes in the cumulus and one that responds to the interspecific signal, cis-9-tetradecenal, and arborizes in the dorsomedial unit. A third type responded to the secondary pheromone component, cis-11-hexadecenal, and innervated the smaller ventral unit. The results complement previous findings from tracing of physiologically identified receptor neurons and determine for the first time the functional specificity of each glomerulus in the MGC of H. assulta. The results are particularly interesting because heliothine moths are attractive objects for comparative studies addressing questions concerning divergence of male-specific olfactory characteristics related to speciation.
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http://dx.doi.org/10.1093/chemse/bjq043DOI Listing
July 2010

Does the onset of sexual maturation terminate the expression of migratory behaviour in moths? A study of the oriental armyworm, Mythimna separata.

J Insect Physiol 2009 Nov 7;55(11):1039-43. Epub 2009 Aug 7.

State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, PR China.

It is generally accepted that in most insects adults are sexually immature when they initiate migration and that migratory behaviour terminates with the onset of sexual maturation. However, a few studies examining the mating status of field collected moths have suggested that sexually mature individuals may continue migrating, but in these cases it was impossible to completely eliminate the possibility that the mated females captured came from local, non-migrant populations. In this study we examined the ovarian development of Mythimna separata females captured using a vertical pointing searchlight trap on Beihuang Island in the Bohai Gulf, China, a site >40km from land. Moths were collected from May to October from 2003 to 2008 in order to test the hypothesis that the onset of sexual maturation resulted in the termination of migratory behaviour. While females at the end of the summer had little ovarian development and were unmated, a significant proportion of those migrating northward in the early summer had developed ovaries and often had at least one spermatophore. Given that theses insects were captured while flying up to 500m above sea level, at a site with no local populations, the findings would not support the hypothesis and suggest that both ovarian development and mating may occur during migration.
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http://dx.doi.org/10.1016/j.jinsphys.2009.07.007DOI Listing
November 2009

Morphological and physiological characteristics of the serotonin-immunoreactive neuron in the antennal lobe of the male oriental tobacco budworm, Helicoverpa assulta.

Chem Senses 2009 Jun 20;34(5):363-72. Epub 2009 Mar 20.

Department of Psychology/Neuroscience Unit, MTFS, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.

We have characterized, by intracellular recording and staining combined with immunocytochemistry, a serotonin-immunoreactive neuron in the central olfactory pathway of the male moth Helicoverpa assulta. The neuron joins the unique category of so-called SI antennal-lobe neurons, previously described in several insect species. In similarity with that originally discovered in the sphinx moth Manduca sexta, the neuron identified here has a large soma located posteriorly in the lateral cell cluster of the antennal lobe and an unbranched neurite projecting into the ipsilateral protocerebrum via the inner antennocerebral tract. After bypassing the central body, the axon crosses the midline and extends through the corresponding antennocerebral tract to the contralateral antennal lobe where it innervates the entire assembly of glomeruli including the male-specific macroglomerular complex. The neuron arborizes into several fine branches in bilateral protocerebral regions anterior to the calyces of the mushroom bodies, particularly on the contralateral side. The physiology of the neuron revealed 2 distinctly different spiking amplitudes, 1 small showing a relatively high spontaneous activity and 1 large showing low activity. The small-amplitude spikes displayed increased frequency when pheromones and plant odors were blown over the antenna. The large-amplitude spikes, which had an unusually long duration, showed no observable responses.
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http://dx.doi.org/10.1093/chemse/bjp013DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2682443PMC
June 2009

Autumn migration of Mythimna separata (Lepidoptera: Noctuidae) over the Bohai Sea in northern China.

Environ Entomol 2008 Jun;37(3):774-81

State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100094, China.

The autumn migration of Mythimna separata (Walker) (Lepidoptera: Noctuidae) across the Bohai Sea was observed with a scanning entomological radar and a searchlight trap at Beihuang, an island located in the center of the Bohai Gulf of northern China, in 2003-2006. During the autumn migration, M. separata flew at the altitudes of 50-500 m, with a displacement speed of 4-12 m/s, toward the southwest. Variations of area density of the radar targets and of catches in the searchlight trap through the night indicated that the flight duration of M. separata was approximately 10 h. Based on these observations, M. separata that originated in northeastern China (i.e., Liaoning, Jilin, and Heilongjiang provinces and part of the Inner Mongolia autonomous region) could immigrate into eastcentral China and subsequently to southern China (i.e., Fujian, Guangdong, and Guangxi provinces) within a week for overwintering.
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http://dx.doi.org/10.1603/0046-225x(2008)37[774:amomsl]2.0.co;2DOI Listing
June 2008

Behavioral and electrophysiological responses of Helicoverpa assulta, H. armigera (Lepidoptera: Noctuidae), their F1 hybrids and backcross progenies to sex pheromone component blends.

J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2006 Oct 31;192(10):1037-47. Epub 2006 May 31.

State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, The Chinese Academy of Sciences, Beijing 100080, China.

Two sibling species, Helicoverpa assulta and Helicoverpa armigera both use (Z)-9-hexadecenal and (Z)-11-hexadecenal as their sex pheromone components but in almost reversed ratios, 93:7 and 3:97, respectively. H. assulta and H. armigera males performed upwind flight in response to the H. assulta sex pheromone blend (93:7). H. armigera responded strongly to the H. armigera blend (3:97), whereas H. assulta males remained inactive upon exposure to this blend. Both species gave clear dose-dependent electrophysiological responses to (Z)-11-hexadecenal. However, (Z)-9-hexadecenal evoked strong dose-dependent electrophysiological responses in H. assulta males but not in H. armigera. The two male F1 hybrids exhibited similar behavioral responses to two sex pheromone blends and electrophysiological responses to two pheromone components as H. armigera males. This indicated that H. armigera genes appear dominant in determining the behavioral response and electrophysiological responses. Behavioral and electrophysiological responses of backcrosses of male F1 hybrids (H. armigera female x H. assulta male) with female H. assulta and H. armigera were close to that of H. assulta and H. armigera, respectively. However, backcrosses of female F1 hybrids (H. assulta female x H. armigera male) with male H. assulta and H. armigera showed reduced behavioral responses but normal electrophysiological responses compared to males of the respective parental line.
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http://dx.doi.org/10.1007/s00359-006-0141-6DOI Listing
October 2006
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