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Pírez N, Klappenbach M, Locatelli FF. Experience-dependent tuning of the olfactory system. CURRENT OPINION IN INSECT SCIENCE 2023; 60:101117. [PMID: 37741614 DOI: 10.1016/j.cois.2023.101117] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 09/12/2023] [Accepted: 09/14/2023] [Indexed: 09/25/2023]
Abstract
Insects rely on their sense of smell to navigate complex environments and make decisions regarding food and reproduction. However, in natural settings, the odors that convey this information may come mixed with environmental odors that can obscure their perception. Therefore, recognizing the presence of informative odors involves generalization and discrimination processes, which can be facilitated when there is a high contrast between stimuli, or the internal representation of the odors of interest outcompetes that of concurrent ones. The first two layers of the olfactory system, which involve the detection of odorants by olfactory receptor neurons and their encoding by the first postsynaptic partners in the antennal lobe, are critical for achieving such optimal representation. In this review, we summarize evidence indicating that experience-dependent changes adjust these two levels of the olfactory system. These changes are discussed in the context of the advantages they provide for detection of informative odors.
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Affiliation(s)
- Nicolás Pírez
- Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Instituto de Fisiología, Biología Molecular y Neurociencias, CONICET, C1428EHA Buenos Aires, Argentina
| | - Martín Klappenbach
- Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Instituto de Fisiología, Biología Molecular y Neurociencias, CONICET, C1428EHA Buenos Aires, Argentina
| | - Fernando F Locatelli
- Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Instituto de Fisiología, Biología Molecular y Neurociencias, CONICET, C1428EHA Buenos Aires, Argentina.
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2
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Lianguzova A, Arbuzova N, Laskova E, Gafarova E, Repkin E, Matach D, Enshina I, Miroliubov A. Tricks of the puppet masters: morphological adaptations to the interaction with nervous system underlying host manipulation by rhizocephalan barnacle Polyascus polygeneus. PeerJ 2023; 11:e16348. [PMID: 38025701 PMCID: PMC10655712 DOI: 10.7717/peerj.16348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 10/03/2023] [Indexed: 12/01/2023] Open
Abstract
Background Rhizocephalan interaction with their decapod hosts is a superb example of host manipulation. These parasites are able to alter the host's physiology and behavior. Host-parasite interaction is performed, presumably, via special modified rootlets invading the ventral ganglions. Methods In this study, we focus on the morphology and ultrastructure of these special rootlets in Polyascus polygeneus (Lützen & Takahashi, 1997), family Polyascidae, invading the neuropil of the host's nervous tissue. The ventral ganglionic mass of the infected crabs were fixed, and the observed sites of the host-parasite interplay were studied using transmission electron microscopy, immunolabeling and confocal microscopy. Results The goblet-shaped organs present in the basal families of parasitic barnacles were presumably lost in a common ancestor of Polyascidae and crown "Akentrogonida", but the observed invasive rootlets appear to perform similar functions, including the synthesis of various substances which are transferred to the host's nervous tissue. Invasive rootlets significantly differ from trophic ones in cell layer composition and cuticle thickness. Numerous multilamellar bodies are present in the rootlets indicating the intrinsic cell rearrangement. The invasive rootlets of P. polygeneus are enlaced by the thin projections of glial cells. Thus, glial cells can be both the first hosts' respondents to the nervous tissue damage and the mediator of the rhizocephalan interaction with the nervous cells. One of the potential molecules engaged in the relationships of P. polygeneus and its host is serotonin, a neurotransmitter which is found exclusively in the invasive rootlets but not in trophic ones. Serotonin participates in different biological pathways in metazoans including the regulation of aggression in crustaceans, which is reduced in infected crabs. We conclude that rootlets associated with the host's nervous tissue are crucial for the regulation of host-parasite interplay and for evolution of the Rhizocephala.
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Affiliation(s)
- Anastasia Lianguzova
- Department of Invertebrate Zoology, St. Petersburg State University, St Petersburg, Russian Federation
- Laboratory of Parasitic Worms and Protists, Zoological Institute of the Russian Academy of Science, St Petersburg, Russian Federation
| | - Natalia Arbuzova
- Department of Invertebrate Zoology, St. Petersburg State University, St Petersburg, Russian Federation
- Laboratory of Parasitic Worms and Protists, Zoological Institute of the Russian Academy of Science, St Petersburg, Russian Federation
| | - Ekaterina Laskova
- Department of Invertebrate Zoology, St. Petersburg State University, St Petersburg, Russian Federation
| | - Elizaveta Gafarova
- Department of Invertebrate Zoology, St. Petersburg State University, St Petersburg, Russian Federation
| | - Egor Repkin
- Department of Invertebrate Zoology, St. Petersburg State University, St Petersburg, Russian Federation
- Research Park, Center for Molecular and Cell Technologies, St. Petersburg State University, St Petersburg, Russian Federation
| | - Dzmitry Matach
- Department of Invertebrate Zoology, St. Petersburg State University, St Petersburg, Russian Federation
| | - Irina Enshina
- Department of Invertebrate Zoology, St. Petersburg State University, St Petersburg, Russian Federation
| | - Aleksei Miroliubov
- Laboratory of Parasitic Worms and Protists, Zoological Institute of the Russian Academy of Science, St Petersburg, Russian Federation
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3
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Tello JA, Jiang L, Zohar Y, Restifo LL. Drosophila CASK regulates brain size and neuronal morphogenesis, providing a genetic model of postnatal microcephaly suitable for drug discovery. Neural Dev 2023; 18:6. [PMID: 37805506 PMCID: PMC10559581 DOI: 10.1186/s13064-023-00174-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Accepted: 09/08/2023] [Indexed: 10/09/2023] Open
Abstract
BACKGROUND CASK-related neurodevelopmental disorders are untreatable. Affected children show variable severity, with microcephaly, intellectual disability (ID), and short stature as common features. X-linked human CASK shows dosage sensitivity with haploinsufficiency in females. CASK protein has multiple domains, binding partners, and proposed functions at synapses and in the nucleus. Human and Drosophila CASK show high amino-acid-sequence similarity in all functional domains. Flies homozygous for a hypomorphic CASK mutation (∆18) have motor and cognitive deficits. A Drosophila genetic model of CASK-related disorders could have great scientific and translational value. METHODS We assessed the effects of CASK loss of function on morphological phenotypes in Drosophila using established genetic, histological, and primary neuronal culture approaches. NeuronMetrics software was used to quantify neurite-arbor morphology. Standard nonparametric statistics methods were supplemented by linear mixed effects modeling in some cases. Microfluidic devices of varied dimensions were fabricated and numerous fluid-flow parameters were used to induce oscillatory stress fields on CNS tissue. Dissociation into viable neurons and neurite outgrowth in vitro were assessed. RESULTS We demonstrated that ∆18 homozygous flies have small brains, small heads, and short bodies. When neurons from developing CASK-mutant CNS were cultured in vitro, they grew small neurite arbors with a distinctive, quantifiable "bushy" morphology that was significantly rescued by transgenic CASK+. As in humans, the bushy phenotype showed dosage-sensitive severity. To overcome the limitations of manual tissue trituration for neuronal culture, we optimized the design and operation of a microfluidic system for standardized, automated dissociation of CNS tissue into individual viable neurons. Neurons from CASK-mutant CNS dissociated in the microfluidic system recapitulate the bushy morphology. Moreover, for any given genotype, device-dissociated neurons grew larger arbors than did manually dissociated neurons. This automated dissociation method is also effective for rodent CNS. CONCLUSIONS These biological and engineering advances set the stage for drug discovery using the Drosophila model of CASK-related disorders. The bushy phenotype provides a cell-based assay for compound screening. Nearly a dozen genes encoding CASK-binding proteins or transcriptional targets also have brain-development mutant phenotypes, including ID. Hence, drugs that improve CASK phenotypes might also benefit children with disorders due to mutant CASK partners.
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Affiliation(s)
- Judith A Tello
- Graduate Interdisciplinary Program in Neuroscience, University of Arizona, Tucson, AZ, 85721, USA
- Department of Neurology, University of Arizona Health Sciences, 1501 N. Campbell Ave, Tucson, AZ, 85724-5023, USA
- Present address: Department of Molecular Pathobiology, College of Dentistry, New York University, New York, NY, 10010, USA
| | - Linan Jiang
- Department of Aerospace and Mechanical Engineering, University of Arizona, Tucson, AZ, 85721, USA
| | - Yitshak Zohar
- Department of Aerospace and Mechanical Engineering, University of Arizona, Tucson, AZ, 85721, USA
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ, 85721, USA
- BIO5 Interdisciplinary Research Institute, University of Arizona, Tucson, AZ, 85721, USA
| | - Linda L Restifo
- Graduate Interdisciplinary Program in Neuroscience, University of Arizona, Tucson, AZ, 85721, USA.
- Department of Neurology, University of Arizona Health Sciences, 1501 N. Campbell Ave, Tucson, AZ, 85724-5023, USA.
- BIO5 Interdisciplinary Research Institute, University of Arizona, Tucson, AZ, 85721, USA.
- Department of Cellular & Molecular Medicine, University of Arizona Health Sciences, Tucson, AZ, 85724, USA.
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Wolff GH, Lahondère C, Vinauger C, Rylance E, Riffell JA. Neuromodulation and differential learning across mosquito species. Proc Biol Sci 2023; 290:20222118. [PMID: 36629098 PMCID: PMC9832544 DOI: 10.1098/rspb.2022.2118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 12/06/2022] [Indexed: 01/12/2023] Open
Abstract
Mosquitoes can change their feeding behaviours based on past experiences, such as shifting from biting animals to biting humans or avoiding defensive hosts (Wolff & Riffell 2018 J. Exp. Biol. 221, jeb157131. (doi:10.1242/jeb.157131)). Dopamine is a critical neuromodulator for insects, allowing flexibility in their feeding preferences, but its role in the primary olfactory centre, the antennal lobe (AL), remains unclear (Vinauger et al. 2018 Curr. Biol. 28, 333-344.e8. (doi:10.1016/j.cub.2017.12.015)). It is also unknown whether mosquitoes can learn some odours and not others, or whether different species learn the same odour cues. We assayed aversive olfactory learning in four mosquito species with different host preferences, and found that they differentially learn odours salient to their preferred host. Mosquitoes that prefer humans learned odours found in mammalian skin, but not a flower odour, and a nectar-feeding species only learned a floral odour. Comparing the brains of these four species revealed significantly different innervation patterns in the AL by dopaminergic neurons. Calcium imaging in the Aedes aegypti AL and three-dimensional image analyses of dopaminergic innervation show that glomeruli tuned to learnable odours have significantly higher dopaminergic innervation. Changes in dopamine expression in the insect AL may be an evolutionary mechanism to adapt olfactory learning circuitry without changing brain structure and confer to mosquitoes an ability to adapt to new hosts.
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Affiliation(s)
- Gabriella H. Wolff
- Department of Biology, University of Washington, Seattle, WA 98195-7270, USA
| | - Chloé Lahondère
- Department of Biology, University of Washington, Seattle, WA 98195-7270, USA
| | - Clément Vinauger
- Department of Biology, University of Washington, Seattle, WA 98195-7270, USA
| | - Elizabeth Rylance
- Department of Biology, University of Washington, Seattle, WA 98195-7270, USA
| | - Jeffrey A. Riffell
- Department of Biology, University of Washington, Seattle, WA 98195-7270, USA
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Chvilicek MM, Titos I, Rothenfluh A. The Neurotransmitters Involved in Drosophila Alcohol-Induced Behaviors. Front Behav Neurosci 2020; 14:607700. [PMID: 33384590 PMCID: PMC7770116 DOI: 10.3389/fnbeh.2020.607700] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 11/23/2020] [Indexed: 12/18/2022] Open
Abstract
Alcohol is a widely used and abused substance with numerous negative consequences for human health and safety. Historically, alcohol's widespread, non-specific neurobiological effects have made it a challenge to study in humans. Therefore, model organisms are a critical tool for unraveling the mechanisms of alcohol action and subsequent effects on behavior. Drosophila melanogaster is genetically tractable and displays a vast behavioral repertoire, making it a particularly good candidate for examining the neurobiology of alcohol responses. In addition to being experimentally amenable, Drosophila have high face and mechanistic validity: their alcohol-related behaviors are remarkably consistent with humans and other mammalian species, and they share numerous conserved neurotransmitters and signaling pathways. Flies have a long history in alcohol research, which has been enhanced in recent years by the development of tools that allow for manipulating individual Drosophila neurotransmitters. Through advancements such as the GAL4/UAS system and CRISPR/Cas9 mutagenesis, investigation of specific neurotransmitters in small subsets of neurons has become ever more achievable. In this review, we describe recent progress in understanding the contribution of seven neurotransmitters to fly behavior, focusing on their roles in alcohol response: dopamine, octopamine, tyramine, serotonin, glutamate, GABA, and acetylcholine. We chose these small-molecule neurotransmitters due to their conservation in mammals and their importance for behavior. While neurotransmitters like dopamine and octopamine have received significant research emphasis regarding their contributions to behavior, others, like glutamate, GABA, and acetylcholine, remain relatively unexplored. Here, we summarize recent genetic and behavioral findings concerning these seven neurotransmitters and their roles in the behavioral response to alcohol, highlighting the fitness of the fly as a model for human alcohol use.
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Affiliation(s)
- Maggie M. Chvilicek
- Department of Psychiatry, University of Utah, Salt Lake City, UT, United States
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, United States
- Neuroscience Graduate Program, University of Utah, Salt Lake City, UT, United States
| | - Iris Titos
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, United States
| | - Adrian Rothenfluh
- Department of Psychiatry, University of Utah, Salt Lake City, UT, United States
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, United States
- Neuroscience Graduate Program, University of Utah, Salt Lake City, UT, United States
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, UT, United States
- Department of Human Genetics, University of Utah, Salt Lake City, UT, United States
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Serotonin transporter dependent modulation of food-seeking behavior. PLoS One 2020; 15:e0227554. [PMID: 31978073 PMCID: PMC6980608 DOI: 10.1371/journal.pone.0227554] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 12/20/2019] [Indexed: 11/28/2022] Open
Abstract
The olfactory pathway integrates the odor information required to generate correct behavioral responses. To address how changes of serotonin signaling in two contralaterally projecting, serotonin-immunoreactive deutocerebral neurons impacts key odorant attraction in Drosophila melanogaster, we selectively alter serotonin signaling using the serotonin transporter with mutated serotonin binding sites in these neurons and analyzed the consequence on odorant-guided food seeking. The expression of the mutated serotonin transporter selectively changed the odorant attraction in an odorant-specific manner. The shift in attraction was not influenced by more up-stream serotonergic mechanisms mediating behavioral inhibition. The expression of the mutated serotonin transporter in CSD neurons did not influence other behaviors associated with food seeking such as olfactory learning and memory or food consumption. We provide evidence that the change in the attraction by serotonin transporter function might be achieved by increased serotonin signaling and by different serotonin receptors. The 5-HT1B receptor positively regulated the attraction to low and negatively regulated the attraction to high concentrations of acetic acid. In contrast, 5-HT1A and 5-HT2A receptors negatively regulated the attraction in projection neurons to high acetic acid concentrations. These results provide insights into how serotonin signaling in two serotonergic neurons selectively regulates the behavioral response to key odorants during food seeking.
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7
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Vafopoulou X, Hindley-Smith M, Steel CGH. Neuropeptide- and serotonin- cells in the brain of Rhodnius prolixus (Hemiptera) associated with the circadian clock. Gen Comp Endocrinol 2019; 278:25-41. [PMID: 30048647 DOI: 10.1016/j.ygcen.2018.07.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 07/16/2018] [Accepted: 07/20/2018] [Indexed: 11/24/2022]
Abstract
The neuronal pathways of the circadian clock in the brain of R. prolixus have been described in detail previously, but there is no information concerning the cells or their pathways which relay either inputs to the clock (e.g. for light entrainment), or outputs from it to driven rhythms. Here, we employ antisera to three neuropeptides (type A allatostatin-7, crustacean cardioactive peptide and FMRFamide), and serotonin in confocal laser scanning immunohistochemistry to analyze the distribution of cell bodies and their projections in relation to the principle circadian clock cells (lateral cells, LNs) for all four neuron types. LNs are revealed following labelling with anti- pigment dispersing factor in double labelled preparations. Regions of potential communication between ramifications of the LNs and each of the four other neuron types is described (identified by close superposition of their neurites in various brain regions), as is their detailed projections within the brain. Neuromodulation is sometimes suggested by close, but not intimate, proximity of varicosities of neurites. We infer that some neuron types comprise input pathways to the LNs, some are outputs to neuroendocrine or behavioral rhythms, and others participate in both input and output pathways, sometimes by the same neuron type but in different locations. For example, one retinula cell in each ommatidium is immunoreactive for allatostatin A; its axon projects to the medulla making superpositions with LNs, as do serotonin cells in the optic lobe, indicating roles of both neuron types in light input (entrainment) to the clock. But in other brain areas, these same types appear to mediate outputs from the clock. The accessory medulla has been widely reported as the principle center of integration in other insects; but we found sparse evidence of this in R. prolixus as it contains few neurites other than those from the clock cells. Rather, the importance of neural pathways involving the medulla and the superior protocerebrum is emphasized. We conclude that there is a vast and complex web of interactions in the brain with the LNs, which potentially receive multiple pathways of inputs and outputs that could drive rhythmicity in a multitude of downstream cells, rendering a host of output pathways rhythmic, notably hormone release from neurosecretory cells and behaviors.
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8
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Tang QB, Song WW, Chang YJ, Xie GY, Chen WB, Zhao XC. Distribution of Serotonin-Immunoreactive Neurons in the Brain and Gnathal Ganglion of Caterpillar Helicoverpa armigera. Front Neuroanat 2019; 13:56. [PMID: 31191263 PMCID: PMC6547022 DOI: 10.3389/fnana.2019.00056] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 05/14/2019] [Indexed: 02/05/2023] Open
Abstract
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 Helicoverpa armigera. In the present study, we performed immunohistochemical experiments with anti-serotonin serum to examine the distribution of serotonin in the central nervous system of H. armigera 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 H. armigera 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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Affiliation(s)
- Qing-Bo Tang
- Department of Entomology, College of Plant Protection, Henan Agricultural University, Zhengzhou, China
| | - Wei-Wei Song
- Department of Entomology, College of Plant Protection, Henan Agricultural University, Zhengzhou, China
| | - Ya-Jun Chang
- Department of Entomology, College of Plant Protection, Henan Agricultural University, Zhengzhou, China
| | - Gui-Ying Xie
- Department of Entomology, College of Plant Protection, Henan Agricultural University, Zhengzhou, China
| | - Wen-Bo Chen
- Department of Entomology, College of Plant Protection, Henan Agricultural University, Zhengzhou, China
| | - Xin-Cheng Zhao
- Department of Entomology, College of Plant Protection, Henan Agricultural University, Zhengzhou, China
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Rittschof CC, Vekaria HJ, Palmer JH, Sullivan PG. Biogenic amines and activity levels alter the neural energetic response to aggressive social cues in the honey bee Apis mellifera. J Neurosci Res 2019; 97:991-1003. [PMID: 31090236 DOI: 10.1002/jnr.24443] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 04/24/2019] [Accepted: 04/24/2019] [Indexed: 01/18/2023]
Abstract
Mitochondrial activity is highly dynamic in the healthy brain, and it can reflect both the signaling potential and the signaling history of neural circuits. Recent studies spanning invertebrates to mammals have highlighted a role for neural mitochondrial dynamics in learning and memory processes as well as behavior. In the current study, we investigate the interplay between biogenic amine signaling and neural energetics in the honey bee, Apis mellifera. In this species, aggressive behaviors are regulated by neural energetic state and biogenic amine titers, but it is unclear how these mechanisms are linked to impact behavioral expression. We show that brain mitochondrial number is highest in aggression-relevant brain regions and in individual bees that are most responsive to aggressive cues, emphasizing the importance of energetics in modulating this phenotype. We also show that the neural energetic response to alarm pheromone, an aggression inducing social cue, is activity dependent, modulated by the "fight or flight" insect neurotransmitter octopamine. Two other neuroactive compounds known to cause variation in aggression, dopamine, and serotonin, also modulate neural energetic state in aggression-relevant regions of the brain. However, the effects of these compounds on respiration at baseline and following alarm pheromone exposure are distinct, suggesting unique mechanisms underlying variation in mitochondrial respiration in these circuits. These results motivate new explanations for the ways in which biogenic amines alter sensory perception in the context of aggression. Considering neural energetics improves predictions about the regulation of complex and context-dependent behavioral phenotypes.
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Affiliation(s)
- Clare C Rittschof
- Department of Entomology, University of Kentucky, Lexington, Kentucky
| | - Hemendra J Vekaria
- Department of Neuroscience, Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky
| | - Joseph H Palmer
- Department of Entomology, University of Kentucky, Lexington, Kentucky
| | - Patrick G Sullivan
- Department of Neuroscience, Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky
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Gassias E, Durand N, Demondion E, Bourgeois T, Aguilar P, Bozzolan F, Debernard S. A critical role for Dop1-mediated dopaminergic signaling in the plasticity of behavioral and neuronal responses to sex pheromone in a moth. J Exp Biol 2019; 222:jeb.211979. [DOI: 10.1242/jeb.211979] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 10/25/2019] [Indexed: 12/22/2022]
Abstract
Most animal species, including insects, are able to modulate their responses to sexual chemosignals and this flexibility originates from the remodeling of olfactory areas under the influence of dopaminergic system. In the moth Agrotis ipsilon, the behavioral response of males to the female-emitted sex pheromone increases throughout adult life and after a prior exposure to pheromone signal and this change is accompanied by an increase in neuronal sensitivity within the primary olfactory centers, the antennal lobes (ALs). To identify the underlying neuromodulatory mechanisms, we examined whether this age- and experience-dependent olfactory plasticity is mediated by dopamine (DA) through the Dop1 receptor, an ortholog of the vertebrate D1-type dopamine receptors, which is positively coupled to adenylyl cyclase. We cloned A. ipsilon Dop1 (AiDop1) which is expressed predominantly in brain and especially in ALs and its knockdown induced decreased AL cAMP amounts and altered sex pheromone-orientated flight. The levels of DA, AiDop1 expression and cAMP in ALs increased from the third day of adult life and at 24h and 48h following pre-exposure to sex pheromone and the dynamic of these changes correlated with the increased responsiveness to sex pheromone. These results demonstrate that Dop1 is required for the display of male sexual behavior and that age- and experience-related neuronal and behavioral changes are sustained by DA-Dop1 signaling that operates within ALs probably through cAMP-dependent mechanisms in A. ipsilon. Thus, this study expands our understanding of the neuromodulatory mechanisms underlying olfactory plasticity, mechanisms that appear to be highly conserved between insects and mammals.
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Affiliation(s)
- Edmundo Gassias
- Institute of Biology, Complutense University of Madrid, Pozuelo de Alarcon, 28223 Madrid, Spain
| | - Nicolas Durand
- FRE CNRS 3498, Ecologie et Dynamique des Systèmes Anthropisés, Université de Picardie, Jules Verne, 80039 Amiens, France
| | - Elodie Demondion
- Sorbonne Université, INRA, CNRS, UPEC, IRD, Univ. P7, Institute of Ecology and Environmental Sciences of Paris, 78026 Versailles, France
| | - Thomas Bourgeois
- Sorbonne Université, INRA, CNRS, UPEC, IRD, Univ. P7, Institute of Ecology and Environmental Sciences of Paris, 78026 Versailles, France
| | - Paleo Aguilar
- Institute of Biology, Complutense University of Madrid, Pozuelo de Alarcon, 28223 Madrid, Spain
| | - Françoise Bozzolan
- Sorbonne Université, INRA, CNRS, UPEC, IRD, Univ. P7, Institute of Ecology and Environmental Sciences of Paris, 75005 Paris, France
| | - Stéphane Debernard
- Sorbonne Université, INRA, CNRS, UPEC, IRD, Univ. P7, Institute of Ecology and Environmental Sciences of Paris, 75005 Paris, France
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Honda K, Matsumoto J, Sasaki K, Tsuruta Y, Honda Y. Uptake of plant-derived specific alkaloids allows males of a butterfly to copulate. Sci Rep 2018; 8:5516. [PMID: 29615771 PMCID: PMC5882650 DOI: 10.1038/s41598-018-23917-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 03/22/2018] [Indexed: 11/21/2022] Open
Abstract
Certain butterflies utilize plant-acquired alkaloids for their own chemical defense and/or for producing male sex pheromone; a trait known as pharmacophagy. Males of the danaine butterfly, Parantica sita, have been reported to ingest pyrrolizidine alkaloids (PAs) as adults to produce two PA-derived sex pheromone components, viz. danaidone (major) and 7R-hydroxydanaidal. We found, however, that not all PAs that can be precursors for the pheromone serve for mating success of males. Here we show that although the sex pheromone is regarded as a requisite for successful mating, uptake of specific PA(s) (lycopsamine-type PAs) is also imperative for the males to achieve copulation. The increase in the levels of two biogenic amines, octopamine and/or serotonin, in the brain and thoracic ganglia of males fed with specific PA(s) suggested that these alkaloids most likely enhance male mating activity. The results can present new evidence for the evolutionary provenance of pharmacophagous acquisition of PAs in PA-adapted insects.
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Affiliation(s)
- Keiichi Honda
- Department of Biofunctional Science and Technology, Graduate School of Biosphere Science, Hiroshima University, Higashihiroshima, 739-8528, Japan. .,Saijo Ecology Institute, 1387-38 Iida, Hachihonmatsu, Higashihiroshima, 739-0141, Japan.
| | - Junya Matsumoto
- Department of Biofunctional Science and Technology, Graduate School of Biosphere Science, Hiroshima University, Higashihiroshima, 739-8528, Japan
| | - Ken Sasaki
- Graduate School of Agriculture, Tamagawa University, Machida, 194-8610, Japan
| | - Yoshiaki Tsuruta
- Department of Biofunctional Science and Technology, Graduate School of Biosphere Science, Hiroshima University, Higashihiroshima, 739-8528, Japan
| | - Yasuyuki Honda
- Department of Biofunctional Science and Technology, Graduate School of Biosphere Science, Hiroshima University, Higashihiroshima, 739-8528, Japan
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Blenau W, Daniel S, Balfanz S, Thamm M, Baumann A. Dm5-HT 2B: Pharmacological Characterization of the Fifth Serotonin Receptor Subtype of Drosophila melanogaster. Front Syst Neurosci 2017; 11:28. [PMID: 28553207 PMCID: PMC5425475 DOI: 10.3389/fnsys.2017.00028] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 04/25/2017] [Indexed: 11/13/2022] Open
Abstract
Serotonin (5-hydroxytryptamine, 5-HT) is an important regulator of physiological and behavioral processes in both protostomes (e.g., insects) and deuterostomes (e.g., mammals). In insects, serotonin has been found to modulate the heart rate and to control secretory processes, development, circadian rhythms, aggressive behavior, as well as to contribute to learning and memory. Serotonin exerts its activity by binding to and activating specific membrane receptors. The clear majority of these receptors belong to the superfamily of G-protein-coupled receptors. In Drosophila melanogaster, a total of five genes have been identified coding for 5-HT receptors. From this family of proteins, four have been pharmacologically examined in greater detail, so far. While Dm5-HT1A, Dm5-HT1B, and Dm5-HT7 couple to cAMP signaling cascades, the Dm5-HT2A receptor leads to Ca2+ signaling in an inositol-1,4,5-trisphosphate-dependent manner. Based on sequence similarity to homologous genes in other insects, a fifth D. melanogaster gene was uncovered coding for a Dm5-HT2B receptor. Knowledge about this receptor’s pharmacological properties is very limited. This is quite surprising because Dm5-HT2B has been attributed to distinct physiological functions based on genetic interference with its gene expression. Mutations were described reducing the response of the larval heart to 5-HT, and specific knockdown of Dm5-HT2B mRNA in hemocytes resulted in a higher susceptibility of the flies to bacterial infection. To gain deeper understanding of Dm5-HT2B’s pharmacology, we evaluated the receptor’s response to a series of established 5-HT receptor agonists and antagonists in a functional cell-based assay. Metoclopramide and mianserin were identified as two potent antagonists that may allow pharmacological interference with Dm5-HT2B signaling in vitro and in vivo.
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Affiliation(s)
- Wolfgang Blenau
- Cologne Biocenter and Zoological Institute, University of CologneCologne, Germany
| | - Stöppler Daniel
- Department of NMR-Supported Structural Biology, Leibniz-Institut für Molekulare PharmakologieBerlin, Germany
| | - Sabine Balfanz
- Institute of Complex Systems - Cellular Biophysics (ICS-4), Forschungszentrum JülichJülich, Germany
| | - Markus Thamm
- Behavioral Physiology and Sociobiology (Zoology II), Biocenter, University of WürzburgWürzburg, Germany
| | - Arnd Baumann
- Institute of Complex Systems - Cellular Biophysics (ICS-4), Forschungszentrum JülichJülich, Germany
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Scheiner R, Reim T, Søvik E, Entler BV, Barron AB, Thamm M. Learning, gustatory responsiveness and tyramine differences across nurse and forager honeybees. ACTA ACUST UNITED AC 2017; 220:1443-1450. [PMID: 28167800 DOI: 10.1242/jeb.152496] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 01/30/2017] [Indexed: 01/12/2023]
Abstract
Honeybees are well known for their complex division of labor. Each bee sequentially performs a series of social tasks during its life. The changes in social task performance are linked to gross differences in behavior and physiology. We tested whether honeybees performing different social tasks (nursing versus foraging) would differ in their gustatory responsiveness and associative learning behavior in addition to their daily tasks in the colony. Further, we investigated the role of the biogenic amine tyramine and its receptors in the behavior of nurse bees and foragers. Tyramine is an important insect neurotransmitter, which has long been neglected in behavioral studies as it was believed to only act as the metabolic precursor of the better-known amine octopamine. With the increasing number of characterized tyramine receptors in diverse insects, we need to understand the functions of tyramine on its own account. Our findings suggest an important role for tyramine and its two receptors in regulating honeybee gustatory responsiveness, social organization and learning behavior. Foragers, which were more responsive to gustatory stimuli than nurse bees and performed better in appetitive learning, also differed from nurse bees in their tyramine brain titers and in the mRNA expression of a tyramine receptor in the brain. Pharmacological activation of tyramine receptors increased gustatory responsiveness of nurse bees and foragers and improved appetitive learning in nurse bees. These data suggest that a large part of the behavioral differences between honeybees may be directly linked to tyramine signaling in the brain.
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Affiliation(s)
- Ricarda Scheiner
- University of Würzburg, Behavioral Physiology & Sociobiology, Biocenter, Am Hubland, Würzburg 97074, Germany .,University of Potsdam, Institute for Biochemistry and Biology, Potsdam 14476, Germany
| | - Tina Reim
- University of Potsdam, Institute for Biochemistry and Biology, Potsdam 14476, Germany
| | - Eirik Søvik
- Macquarie University, Department of Biological Sciences, Sydney, NSW 2109, Australia.,Volda University College, Department of Science and Mathematics, Volda 6100, Norway
| | - Brian V Entler
- Macquarie University, Department of Biological Sciences, Sydney, NSW 2109, Australia
| | - Andrew B Barron
- Macquarie University, Department of Biological Sciences, Sydney, NSW 2109, Australia
| | - Markus Thamm
- University of Würzburg, Behavioral Physiology & Sociobiology, Biocenter, Am Hubland, Würzburg 97074, Germany
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Reim T, Balfanz S, Baumann A, Blenau W, Thamm M, Scheiner R. AmTAR2: Functional characterization of a honeybee tyramine receptor stimulating adenylyl cyclase activity. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2017; 80:91-100. [PMID: 27939988 DOI: 10.1016/j.ibmb.2016.12.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Revised: 12/02/2016] [Accepted: 12/06/2016] [Indexed: 06/06/2023]
Abstract
The biogenic monoamines norepinephrine and epinephrine regulate important physiological functions in vertebrates. Insects such as honeybees do not synthesize these neuroactive substances. Instead, they employ octopamine and tyramine for comparable physiological functions. These biogenic amines activate specific guanine nucleotide-binding (G) protein-coupled receptors (GPCRs). Based on pharmacological data obtained on heterologously expressed receptors, α- and β-adrenergic-like octopamine receptors are better activated by octopamine than by tyramine. Conversely, GPCRs forming the type 1 tyramine receptor clade (synonymous to octopamine/tyramine receptors) are better activated by tyramine than by octopamine. More recently, receptors were characterized which are almost exclusively activated by tyramine, thus forming an independent type 2 tyramine receptor clade. Functionally, type 1 tyramine receptors inhibit adenylyl cyclase activity, leading to a decrease in intracellular cAMP concentration ([cAMP]i). Type 2 tyramine receptors can mediate Ca2+ signals or both Ca2+ signals and effects on [cAMP]i. We here provide evidence that the honeybee tyramine receptor 2 (AmTAR2), when heterologously expressed in flpTM cells, exclusively causes an increase in [cAMP]i. The receptor displays a pronounced preference for tyramine over octopamine. Its activity can be blocked by a series of established antagonists, of which mianserin and yohimbine are most efficient. The functional characterization of two tyramine receptors from the honeybee, AmTAR1 (previously named AmTYR1) and AmTAR2, which respond to tyramine by changing cAMP levels in opposite direction, is an important step towards understanding the actions of tyramine in honeybee behavior and physiology, particularly in comparison to the effects of octopamine.
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Affiliation(s)
- Tina Reim
- Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany
| | - Sabine Balfanz
- Institute of Complex Systems, ICS-4, Forschungszentrum Jülich, Jülich, Germany
| | - Arnd Baumann
- Institute of Complex Systems, ICS-4, Forschungszentrum Jülich, Jülich, Germany
| | - Wolfgang Blenau
- Zoological Institute, University of Cologne, Cologne, Germany
| | - Markus Thamm
- Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany; Behavioral Physiology and Sociobiology (Zoology II), Biocenter, University of Würzburg, Würzburg, Germany
| | - Ricarda Scheiner
- Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany; Behavioral Physiology and Sociobiology (Zoology II), Biocenter, University of Würzburg, Würzburg, Germany.
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15
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Xu L, He J, Kaiser A, Gräber N, Schläger L, Ritze Y, Scholz H. A Single Pair of Serotonergic Neurons Counteracts Serotonergic Inhibition of Ethanol Attraction in Drosophila. PLoS One 2016; 11:e0167518. [PMID: 27936023 PMCID: PMC5147910 DOI: 10.1371/journal.pone.0167518] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 11/15/2016] [Indexed: 11/18/2022] Open
Abstract
Attraction to ethanol is common in both flies and humans, but the neuromodulatory mechanisms underlying this innate attraction are not well understood. Here, we dissect the function of the key regulator of serotonin signaling—the serotonin transporter–in innate olfactory attraction to ethanol in Drosophila melanogaster. We generated a mutated version of the serotonin transporter that prolongs serotonin signaling in the synaptic cleft and is targeted via the Gal4 system to different sets of serotonergic neurons. We identified four serotonergic neurons that inhibit the olfactory attraction to ethanol and two additional neurons that counteract this inhibition by strengthening olfactory information. Our results reveal that compensation can occur on the circuit level and that serotonin has a bidirectional function in modulating the innate attraction to ethanol. Given the evolutionarily conserved nature of the serotonin transporter and serotonin, the bidirectional serotonergic mechanisms delineate a basic principle for how random behavior is switched into targeted approach behavior.
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Affiliation(s)
- Li Xu
- Zoology, Albertus Magnus University Cologne, Köln, Germany
| | - Jianzheng He
- Zoology, Albertus Magnus University Cologne, Köln, Germany
| | - Andrea Kaiser
- Zoology, Albertus Magnus University Cologne, Köln, Germany
| | - Nikolas Gräber
- Zoology, Albertus Magnus University Cologne, Köln, Germany
| | - Laura Schläger
- Zoology, Albertus Magnus University Cologne, Köln, Germany
| | - Yvonne Ritze
- Institute of Genetics and Neurobiology, Julius Maximillian University Würzburg, Würzburg, Germany
| | - Henrike Scholz
- Zoology, Albertus Magnus University Cologne, Köln, Germany
- Institute of Genetics and Neurobiology, Julius Maximillian University Würzburg, Würzburg, Germany
- * E-mail:
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Berens AJ, Tibbetts EA, Toth AL. Candidate genes for individual recognition in Polistes fuscatus paper wasps. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2015; 202:115-29. [PMID: 26660069 DOI: 10.1007/s00359-015-1057-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2015] [Revised: 11/12/2015] [Accepted: 11/13/2015] [Indexed: 12/22/2022]
Abstract
Few animals are known to individually recognize conspecifics, i.e. learn and recall unique individuals during subsequent encounters, and nearly all are social vertebrates. Remarkably, the social paper wasp Polistes fuscatus has recently been discovered to possess this ability, which is useful for remembering identities during competitive social interactions. We analyzed brain gene expression in staged encounters between pairs of individuals to explore potential mechanisms underlying wasps' ability to recall familiar individuals using real-time qRT-PCR. We identified four candidate genes (IP3K, IP3R, Nckx30C and Su(var)2-10) that were down-regulated in the presence of familiar individuals compared to single wasps and pairs of wasps meeting for the first time. These candidate genes are related to calcium signaling, therefore, we treated wasps with lithium chloride, a pharmacological agent that inhibits calcium signaling in neurons. This treatment decreased aggression in paper wasps, but did not affect expression of genes related to calcium signaling. The results suggest calcium signaling differences may be related to individual memory recall in wasps, and we present four promising candidate genes for future study. These data suggest genes associated with dominance behavior may be co-opted for individual recognition, but further work is needed to establish a causal association with the behavior.
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Affiliation(s)
- A J Berens
- Program in Bioinformatics and Computational Biology, Iowa State University, Ames, IA, 50011, USA.
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, 50011, USA.
| | - E A Tibbetts
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - A L Toth
- Program in Bioinformatics and Computational Biology, Iowa State University, Ames, IA, 50011, USA
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, 50011, USA
- Department of Entomology, Iowa State University, Ames, IA, 50011, USA
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Function and distribution of 5-HT2 receptors in the honeybee (Apis mellifera). PLoS One 2013; 8:e82407. [PMID: 24324783 PMCID: PMC3855752 DOI: 10.1371/journal.pone.0082407] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Accepted: 10/23/2013] [Indexed: 11/27/2022] Open
Abstract
Background Serotonin plays a pivotal role in regulating and modulating physiological and behavioral processes in both vertebrates and invertebrates. In the honeybee (Apis mellifera), serotonin has been implicated in division of labor, visual processing, and learning processes. Here, we present the cloning, heterologous expression, and detailed functional and pharmacological characterization of two honeybee 5-HT2 receptors. Methods Honeybee 5-HT2 receptor cDNAs were amplified from brain cDNA. Recombinant cell lines were established constitutively expressing receptor variants. Pharmacological properties of the receptors were investigated by Ca2+ imaging experiments. Quantitative PCR was applied to explore the expression patterns of receptor mRNAs. Results The honeybee 5-HT2 receptor class consists of two subtypes, Am5-HT2α and Am5-HT2β. Each receptor gene also gives rise to alternatively spliced mRNAs that possibly code for truncated receptors. Only activation of the full-length receptors with serotonin caused an increase in the intracellular Ca2+ concentration. The effect was mimicked by the agonists 5-methoxytryptamine and 8-OH-DPAT at low micromolar concentrations. Receptor activities were blocked by established 5-HT receptor antagonists such as clozapine, methiothepin, or mianserin. High transcript numbers were detected in exocrine glands suggesting that 5-HT2 receptors participate in secretory processes in the honeybee. Conclusions This study marks the first molecular and pharmacological characterization of two 5-HT2 receptor subtypes in the same insect species. The results presented should facilitate further attempts to unravel central and peripheral effects of serotonin mediated by these receptors.
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Clifford MR, Riffell JA. Mixture and odorant processing in the olfactory systems of insects: a comparative perspective. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2013; 199:911-28. [PMID: 23660810 DOI: 10.1007/s00359-013-0818-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Revised: 04/06/2013] [Accepted: 04/08/2013] [Indexed: 01/18/2023]
Abstract
Natural olfactory stimuli are often complex mixtures of volatiles, of which the identities and ratios of constituents are important for odor-mediated behaviors. Despite this importance, the mechanism by which the olfactory system processes this complex information remains an area of active study. In this review, we describe recent progress in how odorants and mixtures are processed in the brain of insects. We use a comparative approach toward contrasting olfactory coding and the behavioral efficacy of mixtures in different insect species, and organize these topics around four sections: (1) Examples of the behavioral efficacy of odor mixtures and the olfactory environment; (2) mixture processing in the periphery; (3) mixture coding in the antennal lobe; and (4) evolutionary implications and adaptations for olfactory processing. We also include pertinent background information about the processing of individual odorants and comparative differences in wiring and anatomy, as these topics have been richly investigated and inform the processing of mixtures in the insect olfactory system. Finally, we describe exciting studies that have begun to elucidate the role of the processing of complex olfactory information in evolution and speciation.
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Affiliation(s)
- Marie R Clifford
- Department of Biology, University of Washington, Seattle, WA, 98195, USA,
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