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Suo S. Sperm function is required for suppressing locomotor activity of C. elegans hermaphrodites. PLoS One 2024; 19:e0297802. [PMID: 38271363 PMCID: PMC10810530 DOI: 10.1371/journal.pone.0297802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 01/12/2024] [Indexed: 01/27/2024] Open
Abstract
Sex differences in sex-shared behavior are common across various species. During mating, males transfer sperm and seminal fluid to females, which can affect female behavior. Sperm can be stored in the female reproductive tract for extended periods of time and used to fertilize eggs. However, the role of either sperm or embryo production in regulating female behavior is poorly understood. In the androdioecious nematode C. elegans, hermaphrodites produce both oocytes and sperm, enabling them to self-fertilize or mate with males. Hermaphrodites exhibit less locomotor activity compared to males, indicating sex difference in behavioral regulation. In this study, mutants defective in the sperm production and function were examined to investigate the role of sperm function in the regulation of locomotor behavior. Infertile hermaphrodites exhibited increased locomotor activity, which was suppressed after mating with fertile males. The results suggest that sperm, seminal fluid, or the presence of embryos are detected by hermaphrodites, leading to a reduction in locomotor activity. Additionally, females of closely related gonochoristic species, C. remanei and C. brenneri, exhibited reduced locomotor activity after mating. The regulation of locomotion by sperm function may be an adaptive mechanism that enables hermaphrodites lacking sperm or embryo to search for mates and allow females to cease their search for mates after mating.
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Affiliation(s)
- Satoshi Suo
- Department of Pharmacology, Faculty of Medicine, Saitama Medical University, Saitama, Japan
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2
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Ravens A, Stacher-Hörndli CN, Emery J, Steinwand S, Shepherd JD, Gregg C. Arc regulates a second-guessing cognitive bias during naturalistic foraging through effects on discrete behavior modules. iScience 2023; 26:106761. [PMID: 37216088 PMCID: PMC10196573 DOI: 10.1016/j.isci.2023.106761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 11/29/2022] [Accepted: 04/24/2023] [Indexed: 05/24/2023] Open
Abstract
Foraging in animals relies on innate decision-making heuristics that can result in suboptimal cognitive biases in some contexts. The mechanisms underlying these biases are not well understood, but likely involve strong genetic effects. To explore this, we studied fasted mice using a naturalistic foraging paradigm and discovered an innate cognitive bias called "second-guessing." This involves repeatedly investigating an empty former food patch instead of consuming available food, which hinders the mice from maximizing feeding benefits. The synaptic plasticity gene Arc is revealed to play a role in this bias, as Arc-deficient mice did not exhibit second-guessing and consumed more food. In addition, unsupervised machine learning decompositions of foraging identified specific behavior sequences, or "modules", that are affected by Arc. These findings highlight the genetic basis of cognitive biases in decision making, show links between behavior modules and cognitive bias, and provide insight into the ethological roles of Arc in naturalistic foraging.
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Affiliation(s)
- Alicia Ravens
- University of Utah, Department of Neurobiology, Salt Lake City, UT, USA
| | | | - Jared Emery
- Storyline Health Inc., Salt Lake City, UT, USA
| | - Susan Steinwand
- University of Utah, Department of Neurobiology, Salt Lake City, UT, USA
| | - Jason D. Shepherd
- University of Utah, Department of Neurobiology, Salt Lake City, UT, USA
- University of Utah, Department of Biochemistry School of Medicine, Salt Lake City, UT, USA
- University of Utah, Department of Ophthalmology & Visual Sciences, Salt Lake City, UT, USA
| | - Christopher Gregg
- University of Utah, Department of Neurobiology, Salt Lake City, UT, USA
- University of Utah, Department of Human Genetics, Salt Lake City, UT, USA
- Storyline Health Inc., Salt Lake City, UT, USA
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3
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Rogers SM, Kostarakos K, Hedwig B. An auditory-responsive interneuron descending from the cricket brain: a new element in the auditory pathway. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2022; 208:571-589. [PMID: 36208310 PMCID: PMC9734236 DOI: 10.1007/s00359-022-01577-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 09/02/2022] [Accepted: 09/22/2022] [Indexed: 12/14/2022]
Abstract
Crickets receive auditory information from their environment via ears located on the front legs. Ascending interneurons forward auditory activity to the brain, which houses a pattern recognition network for phonotaxis to conspecific calling songs and which controls negative phonotaxis to high-frequency sound pulses. Descending brain neurons, however, which are clearly involved in controlling these behaviors, have not yet been identified. We describe a descending auditory-responsive brain neuron with an arborization pattern that coincides with the ring-like auditory neuropil in the brain formed by the axonal arborizations of ascending and local interneurons, indicating its close link to auditory processing. Spiking activity of this interneuron occurs with a short latency to calling song patterns and the neuron copies the sound pulse pattern. The neuron preferentially responds to short sound pulses, but its activity appears to be independent of the calling song pattern recognition process. It also receives a weaker synaptic input in response to high-frequency pulses, which may contribute to its short latency spiking responses. This interneuron could be a crucial part in the auditory-to-motor transformation of the nervous system and contribute to the motor control of cricket auditory behavior.
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Affiliation(s)
- Stephen M. Rogers
- grid.5335.00000000121885934Department of Zoology, University of Cambridge, Cambridge, CB2 3EJ
UK ,grid.36511.300000 0004 0420 4262Department of Life Sciences, University of Lincoln, Brayford Pool Campus, Lincoln, LN6 7TS UK
| | | | - Berthold Hedwig
- grid.5335.00000000121885934Department of Zoology, University of Cambridge, Cambridge, CB2 3EJ
UK
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4
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Shadrin N, Yakovenko V, Anufriieva E. The behavior of Gammarus aequicauda (crustacea, amphipoda) during predation on chironomid larvae: Sex differences and changes in precopulatory mate-guarding state. JOURNAL OF EXPERIMENTAL ZOOLOGY PART 2021; 335:572-582. [PMID: 34184831 DOI: 10.1002/jez.2500] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 06/02/2021] [Accepted: 06/07/2021] [Indexed: 11/09/2022]
Abstract
The foraging behavior determines the diet size influencing the growth and reproduction of a predator and its prey populations. Amphipods play a key role in various aquatic ecosystems. Gammarus aequicauda is an abundant widespread omnivorous species and the only known amphipod species of hypersaline waters. Its predation can suppress the populations of planktonic and benthic invertebrates. Males of G. aequicauda actively eat chironomid larvae but there is no data on predatory females. Experiments were conducted to study sex-related differences in feeding behavior including during precopulatory mate guarding (PCMG). There were significant sex differences in feeding characteristics. For females, calculations showed that maximum consumption could be 3-4 chironomid larvae per day and for males about 9-10 larvae per day. During PCMG, males did not feed and females fed as efficiently as single females. Males transported females and alone carrying the energetic costs of swimming during PCMG. Less expenditure of energy on swimming means more energy for reproduction for females. This allows more energy-efficient use of food resources and increases the reproductive success of the population. There are currently two alternative views on PCMG among crustaceans. 1. It is a sexual conflict between males and females serving as a male adaptive strategy to achieve a female during strong male competition, while females bear many costs during the long guarding period. 2. There is also the opposite view that pairs get energetic benefits from long PCMG. Obtained data suggest that PCMG is likely to be intersexual cooperation and not intersexual conflict.
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Affiliation(s)
- Nickolai Shadrin
- Laboratory of Extreme Ecosystems, A.O. Kovalevsky Institute of Biology of the Southern Seas of RAS, Sevastopol, Russia
| | - Vladimir Yakovenko
- Laboratory of Extreme Ecosystems, A.O. Kovalevsky Institute of Biology of the Southern Seas of RAS, Sevastopol, Russia
| | - Elena Anufriieva
- Laboratory of Extreme Ecosystems, A.O. Kovalevsky Institute of Biology of the Southern Seas of RAS, Sevastopol, Russia
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5
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Fontana BD, Gibbon AJ, Cleal M, Norton WHJ, Parker MO. Chronic unpredictable early-life stress (CUELS) protocol: Early-life stress changes anxiety levels of adult zebrafish. Prog Neuropsychopharmacol Biol Psychiatry 2021; 108:110087. [PMID: 32889032 DOI: 10.1016/j.pnpbp.2020.110087] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 08/26/2020] [Accepted: 08/27/2020] [Indexed: 12/24/2022]
Abstract
Early-life stress can lead to two different behavioral responses: (1) increased susceptibility to psychiatric disorders or (2) resilience. Here, we created a chronic unpredictable early-life stress (CUELS) protocol to assess the effects of early experiences in adult zebrafish. Animals were exposed to mild stressors twice a day and the duration was varied between groups (0, 1, 3, 7 and 14 days of stress). The stressor consisted of light/dark cycle changes; social isolation; overcrowding; water changes; water cooling; mechanical stirring; water heating; and immersion in shallow water. Behavior was assessed at young stages (21 days post-fertilization - open field analysis) and adulthood (4-months-old - novel tank diving test, light/dark task, shoaling, free movement pattern Y-maze and Pavlovian fear conditioning). Cortisol levels were assessed to evaluate the impact of CUELS in the HPI axis. Zebrafish exposed to 7 days of CUELS showed a decreased anxiety-like phenotype in two behavioral tasks, presenting increased time spent in top and decreased time spent in the dark area. Animals exposed to 14 days of CUELS showed an opposite anxious phenotype compared to 3 and 7 days of CUELS. No significant changes were observed in memory and cognition, social behavior and cortisol levels. In general, 7 days of CUELS protocol decreased anxiety in young and adult zebrafish, and could be used to understand the mechanisms underlying early-life experiences-derived alterations in neural circuits of anxiety.
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Affiliation(s)
- Barbara D Fontana
- Brain and Behaviour Laboratory, School of Pharmacy and Biomedical Sciences, University of Portsmouth, UK.
| | - Alistair J Gibbon
- Brain and Behaviour Laboratory, School of Pharmacy and Biomedical Sciences, University of Portsmouth, UK
| | - Madeleine Cleal
- Brain and Behaviour Laboratory, School of Pharmacy and Biomedical Sciences, University of Portsmouth, UK
| | - William H J Norton
- Department of Neuroscience, Psychology and Behaviour, College of Medicine, Biological Sciences and Psychology, University of Leicester, Leicester LE1 7RH, UK; The International Zebrafish Neuroscience Research Consortium (ZNRC), 309 Palmer Court, Slidell, LA 70458, USA
| | - Matthew O Parker
- Brain and Behaviour Laboratory, School of Pharmacy and Biomedical Sciences, University of Portsmouth, UK; The International Zebrafish Neuroscience Research Consortium (ZNRC), 309 Palmer Court, Slidell, LA 70458, USA.
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6
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Deng Z, Zhang Y, Zhang M, Huang J, Li C, Ni X, Li X. Characterization of the First W-Specific Protein-Coding Gene for Sex Identification in Helicoverpa armigera. Front Genet 2020; 11:649. [PMID: 32636875 PMCID: PMC7317607 DOI: 10.3389/fgene.2020.00649] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 05/28/2020] [Indexed: 12/11/2022] Open
Abstract
Helicoverpa armigera is a globally-important crop pest with a WZ (female)/ZZ (male) sex chromosome system. The absence of discernible sexual dimorphism in its egg and larval stages makes it impossible to address any sex-related theoretical and applied questions before pupation unless a W-specific sequence marker is available for sex diagnosis. To this end, we used one pair of morphologically pre-sexed pupae to PCR-screen 17 non-transposon transcripts selected from 4855 W-linked candidate reads identified by mapping a publicly available egg transcriptome of both sexes to the male genome of this species and detected the read SRR1015458.67499 only in the female pupa. Subsequent PCR screenings of this read and the previously reported female-specific RAPD (random amplified polymorphic DNA) marker AF18 with ten more pairs of pre-sexed pupae and different annealing positions and/or temperatures as well as its co-occurrence with the female-specific transcript splicing isoforms of doublesex gene of H. armigera (Hadsx) and amplification and sequencing of their 5′ unknown flanking sequences in three additional pairs of pre-sexed pupae verified that SRR1015458.67499 is a single copy protein-coding gene unique to W chromosome (named GUW1) while AF18 is a multicopy MITE transposon located on various chromosomes. Test application of GUW1 as a marker to sex 30 neonates of H. armigera yielded a female/male ratio of 1.14: 1.00. Both GUW1 and Hadsx splicing isoforms assays revealed that the H. armigera embryo cell line QB-Ha-E-1 is a male cell line. Taken together, GUW1 is not only a reliable DNA marker for sexing all stages of H. armigera and its cell lines, but also represents the first W-specific protein-coding gene in lepidopterans.
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Affiliation(s)
- Zhongyuan Deng
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou, China.,State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yakun Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Min Zhang
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou, China
| | - Jinyong Huang
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou, China
| | - Changyou Li
- College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao, China
| | - Xinzhi Ni
- Agricultural Research Service, U.S. Department of Agriculture, Crop Genetics and Breeding Research Unit, University of Georgia - Tifton Campus, Tifton, GA, United States
| | - Xianchun Li
- Department of Entomology and BIO5 Institute, University of Arizona, Tucson, AZ, United States
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7
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Warner EJ, Padmanabhan K. Sex differences in head-fixed voluntary running behavior in C57BL/6J mice. Eur J Neurosci 2019; 51:721-730. [PMID: 31849113 PMCID: PMC7069786 DOI: 10.1111/ejn.14654] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Revised: 12/06/2019] [Accepted: 12/13/2019] [Indexed: 12/01/2022]
Abstract
Sex differences in running behaviors between female and male mice occur naturally in the wild. Recent experiments using head-fixed mice on a voluntary running wheel have exploited analogous locomotor activity to gain insight into the neural underpinnings of a number of behaviors ranging from spatial navigation to decision-making. It is however largely unknown if sex differences exist between females and males in a head-fixed experimental paradigm. To address this, we characterized locomotor activity in head-fixed female and male C57BL/6J mice on a voluntary running wheel. First, we found that over the initial 7-day period, on average, animals increased both the velocity and the time spent running. Furthermore, we found that female mice habituated to running forward over the initial 2 days of encountering the wheel, while male mice took up to 4 days to habituate to running forward. Taken together, we characterized features of a sexually divergent behavior in head-fixed running that should be considered in experiments employing female and male mice.
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Affiliation(s)
- Emily J Warner
- Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA.,Neuroscience Graduate Program (NGP), University of Rochester School of Medicine and Dentistry, Rochester, NY, USA.,The Ernest J. Del Monte Institute for Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Krishnan Padmanabhan
- Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA.,Neuroscience Graduate Program (NGP), University of Rochester School of Medicine and Dentistry, Rochester, NY, USA.,The Ernest J. Del Monte Institute for Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA.,Center for Visual Science, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
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8
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Fontana BD, Cleal M, Parker MO. Female adult zebrafish (
Danio rerio
) show higher levels of anxiety‐like behavior than males, but do not differ in learning and memory capacity. Eur J Neurosci 2019; 52:2604-2613. [DOI: 10.1111/ejn.14588] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Revised: 08/15/2019] [Accepted: 09/24/2019] [Indexed: 11/29/2022]
Affiliation(s)
- Barbara D. Fontana
- Brain and Behaviour Laboratory School of Pharmacy and Biomedical Sciences University of Portsmouth Portsmouth UK
| | - Madeleine Cleal
- Brain and Behaviour Laboratory School of Pharmacy and Biomedical Sciences University of Portsmouth Portsmouth UK
| | - Matthew O. Parker
- Brain and Behaviour Laboratory School of Pharmacy and Biomedical Sciences University of Portsmouth Portsmouth UK
- The International Zebrafish Neuroscience Research Consortium (ZNRC) Slidell LA USA
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9
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Brandão ML, Fernandes AMTDA, Gonçalves-de-Freitas E. Male and female cichlid fish show cognitive inhibitory control ability. Sci Rep 2019; 9:15795. [PMID: 31673023 PMCID: PMC6823373 DOI: 10.1038/s41598-019-52384-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 10/14/2019] [Indexed: 12/13/2022] Open
Abstract
Inhibitory control is a way to infer cognitive flexibility in animals by inhibiting a behavioral propensity to obtain a reward. Here we tested whether there are differences in inhibitory control between females and males of the fish Nile tilapia owing to their distinct reproductive roles. Individuals were tested under a detour-reaching paradigm, consisting of training fish to feed behind an opaque barrier and, thereafter, testing them with a transparent one. Fish is expected to avoid trying to cross through the transparent barrier to achieve food (reward), thus showing inhibitory control by recovering the learned detour with the opaque apparatus. Both males and females learned to detour the transparent barrier with similar scores of correct responses, whereas females reached the food faster. This result is probably associated to their different sex roles in reproduction: females care for the eggs and fry inside their mouth (thus requiring a high inhibitory control not to swallow them), whereas males have to stay inside the territory defending it against intruder males, which also demands some inhibitory ability not to leave the spawning site and take the risk of losing it. Furthermore, this evidence of cognitive flexibility can enable social fish to deal with unpredictable interactions.
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Affiliation(s)
- Manuela Lombardi Brandão
- Departamento de Zoologia e Botânica, Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista (UNESP), Cristóvão Colombo, 2265, 15054-000, São José do Rio Preto, SP, Brazil
| | - Ana Marina Tabah de Almeida Fernandes
- Departamento de Zoologia e Botânica, Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista (UNESP), Cristóvão Colombo, 2265, 15054-000, São José do Rio Preto, SP, Brazil
| | - Eliane Gonçalves-de-Freitas
- Departamento de Zoologia e Botânica, Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista (UNESP), Cristóvão Colombo, 2265, 15054-000, São José do Rio Preto, SP, Brazil.
- Centro de Aquicultura da UNESP, São José do Rio Preto, SP, Brasil.
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10
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Suo S, Harada K, Matsuda S, Kyo K, Wang M, Maruyama K, Awaji T, Tsuboi T. Sexually Dimorphic Regulation of Behavioral States by Dopamine in Caenorhabditis elegans. J Neurosci 2019; 39:4668-4683. [PMID: 30988167 PMCID: PMC6561698 DOI: 10.1523/jneurosci.2985-18.2019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2018] [Revised: 03/22/2019] [Accepted: 03/26/2019] [Indexed: 11/21/2022] Open
Abstract
Sex differences in behavior allow animals to effectively mate and reproduce. However, the mechanism by which biological sex regulates behavioral states, which underlie the regulation of sex-shared behaviors, such as locomotion, is largely unknown. In this study, we studied sex differences in the behavioral states of Caenorhabditis elegans and found that males spend less time in a low locomotor activity state than hermaphrodites and that dopamine generates this sex difference. In males, dopamine reduces the low activity state by acting in the same pathway as polycystic kidney disease-related genes that function in male-specific neurons. In hermaphrodites, dopamine increases the low activity state by suppression of octopamine signaling in the sex-shared SIA neurons, which have reduced responsiveness to octopamine in males. Furthermore, dopamine promotes exploration both inside and outside of bacterial lawn (the food source) in males and suppresses it in hermaphrodites. These results demonstrate that sexually dimorphic signaling allows the same neuromodulator to promote adaptive behavior for each sex.SIGNIFICANCE STATEMENT The mechanisms that generate sex differences in sex-shared behaviors, including locomotion, are not well understood. We show that there are sex differences in the regulation of behavioral states in the model animal Caenorhabditis elegans Dopamine promotes the high locomotor activity state in males, which must search for mates to reproduce, and suppresses it in self-fertilizing hermaphrodites through distinct molecular mechanisms. This study demonstrates that sex-specific signaling generates sex differences in the regulation of behavioral states, which in turn modulates the locomotor activity to suit reproduction for each sex.
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Affiliation(s)
- Satoshi Suo
- Department of Pharmacology, Faculty of Medicine, Saitama Medical University, Saitama, 350-0495, Japan,
| | - Kazuki Harada
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Tokyo, 153-8902, Japan
| | - Shogo Matsuda
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Tokyo, 113-0033, Japan, and
| | - Koki Kyo
- Department of Human Sciences, Obihiro University of Agriculture and Veterinary Medicine, Hokkaido, 080-8555, Japan
| | - Min Wang
- Department of Pharmacology, Faculty of Medicine, Saitama Medical University, Saitama, 350-0495, Japan
| | - Kei Maruyama
- Department of Pharmacology, Faculty of Medicine, Saitama Medical University, Saitama, 350-0495, Japan
| | - Takeo Awaji
- Department of Pharmacology, Faculty of Medicine, Saitama Medical University, Saitama, 350-0495, Japan
| | - Takashi Tsuboi
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Tokyo, 153-8902, Japan
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Tokyo, 113-0033, Japan, and
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11
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Krolick KN, Zhu Q, Shi H. Effects of Estrogens on Central Nervous System Neurotransmission: Implications for Sex Differences in Mental Disorders. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2018; 160:105-171. [PMID: 30470289 PMCID: PMC6737530 DOI: 10.1016/bs.pmbts.2018.07.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Nearly one of every five US individuals aged 12 years old or older lives with certain types of mental disorders. Men are more likely to use various types of substances, while women tend to be more susceptible to mood disorders, addiction, and eating disorders, all of which are risks associated with suicidal attempts. Fundamental sex differences exist in multiple aspects of the functions and activities of neurotransmitter-mediated neural circuits in the central nervous system (CNS). Dysregulation of these neural circuits leads to various types of mental disorders. The potential mechanisms of sex differences in the CNS neural circuitry regulating mood, reward, and motivation are only beginning to be understood, although they have been largely attributed to the effects of sex hormones on CNS neurotransmission pathways. Understanding this topic is important for developing prevention and treatment of mental disorders that should be tailored differently for men and women. Studies using animal models have provided important insights into pathogenesis, mechanisms, and new therapeutic approaches of human diseases, but some concerns remain to be addressed. The purpose of this chapter is to integrate human and animal studies involving the effects of the sex hormones, estrogens, on CNS neurotransmission, reward processing, and associated mental disorders. We provide an overview of existing evidence for the physiological, behavioral, cellular, and molecular actions of estrogens in the context of controlling neurotransmission in the CNS circuits regulating mood, reward, and motivation and discuss related pathology that leads to mental disorders.
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Affiliation(s)
- Kristen N Krolick
- Center for Physiology and Neuroscience, Department of Biology, Miami University, Oxford, OH, United States
| | - Qi Zhu
- Center for Physiology and Neuroscience, Department of Biology, Miami University, Oxford, OH, United States
| | - Haifei Shi
- Center for Physiology and Neuroscience, Department of Biology, Miami University, Oxford, OH, United States; Cellular, Molecular and Structural Biology, Miami University, Oxford, OH, United States.
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12
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Fagan KA, Luo J, Lagoy RC, Schroeder FC, Albrecht DR, Portman DS. A Single-Neuron Chemosensory Switch Determines the Valence of a Sexually Dimorphic Sensory Behavior. Curr Biol 2018; 28:902-914.e5. [PMID: 29526590 PMCID: PMC5862148 DOI: 10.1016/j.cub.2018.02.029] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 02/11/2018] [Accepted: 02/14/2018] [Indexed: 01/08/2023]
Abstract
Biological sex, a fundamental dimension of internal state, can modulate neural circuits to generate behavioral variation. Understanding how and why circuits are tuned by sex can provide important insights into neural and behavioral plasticity. Here we find that sexually dimorphic behavioral responses to C. elegans ascaroside sex pheromones are implemented by the functional modulation of shared chemosensory circuitry. In particular, the sexual state of a single sensory neuron pair, ADF, determines the nature of an animal's behavioral response regardless of the sex of the rest of the body. Genetic feminization of ADF causes males to be repelled by, rather than attracted to, ascarosides, whereas masculinization of ADF has the opposite effect in hermaphrodites. When ADF is ablated, both sexes are weakly repelled by ascarosides. Genetic sex modulates ADF function by tuning chemosensation: although ADF is functional in both sexes, it detects the ascaroside ascr#3 only in males, a consequence of cell-autonomous action of the master sexual regulator tra-1. This occurs in part through the conserved DM-domain gene mab-3, which promotes the male state of ADF. The sexual modulation of ADF has a key role in reproductive fitness, as feminization or ablation of ADF renders males unable to use ascarosides to locate mates. Our results reveal an economical mechanism in which sex-specific behavioral valence arises through the cell-autonomous regulation of a chemosensory switch by genetic sex, allowing a social cue with salience for both sexes to elicit navigational responses commensurate with the differing needs of each.
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Affiliation(s)
- Kelli A Fagan
- Neuroscience Graduate Program, University of Rochester, 601 Elmwood Avenue, Rochester, NY 14610, USA
| | - Jintao Luo
- Del Monte Institute for Neuroscience, University of Rochester, 601 Elmwood Avenue, Rochester, NY 14610, USA; Center for Neurotherapeutics Development, University of Rochester, 601 Elmwood Avenue, Rochester, NY 14610, USA
| | - Ross C Lagoy
- Department of Biomedical Engineering, Worcester Polytechnic Institute, 60 Prescott Street, Room 4004, Worcester, MA 01605, USA
| | | | - Dirk R Albrecht
- Department of Biomedical Engineering, Worcester Polytechnic Institute, 60 Prescott Street, Room 4004, Worcester, MA 01605, USA
| | - Douglas S Portman
- Del Monte Institute for Neuroscience, University of Rochester, 601 Elmwood Avenue, Rochester, NY 14610, USA; Center for Neurotherapeutics Development, University of Rochester, 601 Elmwood Avenue, Rochester, NY 14610, USA; Departments of Biomedical Genetics, Neuroscience, and Biology, University of Rochester, 601 Elmwood Avenue, Box 645, Rochester, NY 14610, USA.
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13
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The “highs and lows” of the human brain on dopaminergics: Evidence from neuropharmacology. Neurosci Biobehav Rev 2017. [DOI: 10.1016/j.neubiorev.2017.06.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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14
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Chen D, Sitaraman D, Chen N, Jin X, Han C, Chen J, Sun M, Baker BS, Nitabach MN, Pan Y. Genetic and neuronal mechanisms governing the sex-specific interaction between sleep and sexual behaviors in Drosophila. Nat Commun 2017; 8:154. [PMID: 28754889 PMCID: PMC5533705 DOI: 10.1038/s41467-017-00087-5] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 05/30/2017] [Indexed: 12/13/2022] Open
Abstract
Animals execute one particular behavior among many others in a context-dependent manner, yet the mechanisms underlying such behavioral choice remain poorly understood. Here we studied how two fundamental behaviors, sex and sleep, interact at genetic and neuronal levels in Drosophila. We show that an increased need for sleep inhibits male sexual behavior by decreasing the activity of the male-specific P1 neurons that coexpress the sex determination genes fruM and dsx, but does not affect female sexual behavior. Further, we delineate a sex-specific neuronal circuit wherein the P1 neurons encoding increased courtship drive suppressed male sleep by forming mutually excitatory connections with the fruM-positive sleep-controlling DN1 neurons. In addition, we find that FRUM regulates male courtship and sleep through distinct neural substrates. These studies reveal the genetic and neuronal basis underlying the sex-specific interaction between sleep and sexual behaviors in Drosophila, and provide insights into how competing behaviors are co-regulated. Genes and circuits involved in sleep and sexual arousal have been extensively studied in Drosophila. Here the authors identify the sex determination genes fruitless and doublesex, and a sex-specific P1-DN1 neuronal feedback that governs the interaction between these competing behaviors
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Affiliation(s)
- Dandan Chen
- The Key Laboratory of Developmental Genes and Human Disease, Institute of Life Sciences, Southeast University, Nanjing, 210096, China
| | - Divya Sitaraman
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, Virginia, 20147, USA. .,Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, Connecticut, 06520, USA. .,Department of Psychological Sciences, University of San Diego, San Diego, California, 92110, USA.
| | - Nan Chen
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, Virginia, 20147, USA
| | - Xin Jin
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, Connecticut, 06520, USA
| | - Caihong Han
- The Key Laboratory of Developmental Genes and Human Disease, Institute of Life Sciences, Southeast University, Nanjing, 210096, China
| | - Jie Chen
- The Key Laboratory of Developmental Genes and Human Disease, Institute of Life Sciences, Southeast University, Nanjing, 210096, China
| | - Mengshi Sun
- The Key Laboratory of Developmental Genes and Human Disease, Institute of Life Sciences, Southeast University, Nanjing, 210096, China
| | - Bruce S Baker
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, Virginia, 20147, USA
| | - Michael N Nitabach
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, Virginia, 20147, USA. .,Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, Connecticut, 06520, USA. .,Department of Genetics, Yale School of Medicine, New Haven, Connecticut, 06520, USA. .,Kavli Institute for Neuroscience, Yale School of Medicine, New Haven, Connecticut, 06520, USA.
| | - Yufeng Pan
- The Key Laboratory of Developmental Genes and Human Disease, Institute of Life Sciences, Southeast University, Nanjing, 210096, China. .,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu, 226001, China.
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15
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Burggren W, Souder BM, Ho DH. Metabolic rate and hypoxia tolerance are affected by group interactions and sex in the fruit fly ( Drosophila melanogaster): new data and a literature survey. Biol Open 2017; 6:471-480. [PMID: 28202465 PMCID: PMC5399560 DOI: 10.1242/bio.023994] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Population density and associated behavioral adjustments are potentially important in regulating physiological performance in many animals. In r-selected species like the fruit fly (Drosophila), where population density rapidly shifts in unpredictable and unstable environments, density-dependent physiological adjustments may aid survival of individuals living in a social environment. Yet, how population density (and associated social behaviors) affects physiological functions like metabolism is poorly understood in insects. Additionally, insects often show marked sexual dimorphism (larger females). Thus, in this study on D. melanogaster, we characterized the effects of fly density and sex on both mass-specific routine oxygen consumption (V̇O2) and hypoxia tolerance (PCrit). Females had significantly lower routine V̇O2 (∼4 µl O2 mg−1 h−1) than males (∼6 µl O2 mg−1 h−1) at an average fly density of 28 flies·respirometer chamber−1. However, V̇O2 was inversely related to fly density in males, with V̇O2 ranging from 4 to 11 µl O2 mg−1 h−1 at a density of 10 and 40 flies·chamber−1, respectively (r2=0.58, P<0.001). Female flies showed a similar but less pronounced effect, with a V̇O2 of 4 and 7 µl O2 mg−1 h−1 at a density of 10 and 40 flies·chamber−1, respectively (r2=0.43, P<0.001). PCrit (∼5.5 to 7.5 kPa) varied significantly with density in male (r2=0.50, P<0.01) but not female (r2=0.02, P>0.5) flies, with higher fly densities having a lower PCrit. An extensive survey of the literature on metabolism in fruit flies indicates that not all studies control for, or even report on, fly density and gender, both of which may affect metabolic measurements. Summary: Technical advances allowing oxygen consumption measurement in individual fruit flies actually take them out of their normal highly social context, resulting in higher oxygen consumption rates than in natural groups.
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Affiliation(s)
- Warren Burggren
- Developmental Integrative Biology Group, Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA
| | - BriAnna M Souder
- Developmental Integrative Biology Group, Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA
| | - Dao H Ho
- Department of Clinical Investigation, Tripler Army Medical Center, Honolulu, HI 96859, USA
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16
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Kromann SH, Saveer AM, Binyameen M, Bengtsson M, Birgersson G, Hansson BS, Schlyter F, Witzgall P, Ignell R, Becher PG. Concurrent modulation of neuronal and behavioural olfactory responses to sex and host plant cues in a male moth. Proc Biol Sci 2015; 282:20141884. [PMID: 25621329 DOI: 10.1098/rspb.2014.1884] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Mating has profound effects on animal physiology and behaviour, not only in females but also in males, which we show here for olfactory responses. In cotton leafworm moths, Spodoptera littoralis, odour-mediated attraction to sex pheromone and plant volatiles are modulated after mating, producing a behavioural response that matches the physiological condition of the male insect. Unmated males are attracted by upwind flight to sex pheromone released by calling females, as well as to volatiles of lilac flowers and green leaves of the host plant cotton, signalling adult food and mating sites, respectively. Mating temporarily abolishes male attraction to females and host plant odour, but does not diminish attraction to flowers. This behavioural modulation is correlated with a response modulation in the olfactory system, as shown by electro-physiological recordings from antennae and by functional imaging of the antennal lobe, using natural odours and synthetic compounds. An effect of mating on the olfactory responses to pheromone and cotton plant volatiles but not to lilac flowers indicates the presence of functionally independent neural circuits within the olfactory system. Our results indicate that these circuits interconnect and weigh perception of social and habitat odour signals to generate appropriate behavioural responses according to mating state.
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17
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Borrero-Echeverry F, Becher PG, Birgersson GÃ, Bengtsson M, Witzgall P, Saveer AM. Flight attraction of Spodoptera littoralis (Lepidoptera, Noctuidae) to cotton headspace and synthetic volatile blends. Front Ecol Evol 2015. [DOI: 10.3389/fevo.2015.00056] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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18
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Tejeda MT, Arredondo J, Pérez-Staples D, Ramos-Morales P, Liedo P, Díaz-Fleischer F. Effects of size, sex and teneral resources on the resistance to hydric stress in the tephritid fruit fly Anastrepha ludens. JOURNAL OF INSECT PHYSIOLOGY 2014; 70:73-80. [PMID: 25239667 DOI: 10.1016/j.jinsphys.2014.08.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Revised: 08/21/2014] [Accepted: 08/23/2014] [Indexed: 06/03/2023]
Abstract
Water availability is recognized as one of the most important factors in the distribution and activity of terrestrial organisms. In the case of insects, hydric stress imposes a major challenge for survival because of the small surface-area-to-volume ratio they exhibit. In general, stress resistance is expected to co-vary positively with size; however, this pattern can become obscured in insects that exhibit sexual size dimorphism, as sexes differ in size and/or shape and have dissimilar resource allocations. In the present study, we use an allometric-based approach to (i) assess the desiccation and starvation stress resistance of teneral Anastrepha ludens flies, (ii) disentangle the relationships between resistance, size and sex and (iii) examine the adult fly body differences in water and lipid contents before and after exposure to stress. After controlling for sexual size dimorphism, an allometric increase of resistance with overall size was observed for all stress-based treatments. The scaling exponents that define the proportion of increase resistance varied with size traits and with type and degree of hydric stress. In this allometric relationship, and also in the relationships between mass and wing length and between size and teneral resources, the sexes maintained similar scaling exponents but differed in the intercepts. Males were more resistant to stress than females; this competitive advantage is probably linked to greater amounts of teneral lipids and more water use during stress.
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Affiliation(s)
- M T Tejeda
- INBIOTECA, Universidad Veracruzana, Av. Culturas Veracruzanas No. 101, Col. E. Zapata, CP 91090 Xalapa, Veracruz, Mexico.
| | - J Arredondo
- Departamento de Biología, Ecología y Comportamiento, Desarrollo de métodos, Programa Moscafrut acuerdo SAGARPA-IICA, Camino a cacahoatales S/N, CP 30860 Metapa de Domínguez, Chiapas, Mexico
| | - D Pérez-Staples
- INBIOTECA, Universidad Veracruzana, Av. Culturas Veracruzanas No. 101, Col. E. Zapata, CP 91090 Xalapa, Veracruz, Mexico
| | - P Ramos-Morales
- Laboratorio de Genética y Toxicología Ambiental & Drosophila Stock Center México, Facultad de Ciencias, UNAM, Universidad 3000 Circuito Exterior S/N, C.P. 04510 Ciudad Universitaria, Distrito Federal, Mexico
| | - P Liedo
- El Colegio de la Frontera Sur, Carretera Antiguo Aeropuerto Km 2.5, CP 30700 Tapachula, Chiapas, Mexico
| | - F Díaz-Fleischer
- INBIOTECA, Universidad Veracruzana, Av. Culturas Veracruzanas No. 101, Col. E. Zapata, CP 91090 Xalapa, Veracruz, Mexico
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19
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Ryan DA, Miller RM, Lee K, Neal SJ, Fagan KA, Sengupta P, Portman DS. Sex, age, and hunger regulate behavioral prioritization through dynamic modulation of chemoreceptor expression. Curr Biol 2014; 24:2509-17. [PMID: 25438941 DOI: 10.1016/j.cub.2014.09.032] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 08/04/2014] [Accepted: 09/11/2014] [Indexed: 11/28/2022]
Abstract
BACKGROUND Adaptive behavioral prioritization requires flexible outputs from fixed neural circuits. In C. elegans, the prioritization of feeding versus mate searching depends on biological sex (males will abandon food to search for mates, whereas hermaphrodites will not) as well as developmental stage and feeding status. Previously, we found that males are less attracted than hermaphrodites to the food-associated odorant diacetyl, suggesting that sensory modulation may contribute to behavioral prioritization. RESULTS We show that somatic sex acts cell autonomously to reconfigure the olfactory circuit by regulating a key chemoreceptor, odr-10, in the AWA neurons. Moreover, we find that odr-10 has a significant role in food detection, the regulation of which contributes to sex differences in behavioral prioritization. Overexpression of odr-10 increases male food attraction and decreases off-food exploration; conversely, loss of odr-10 impairs food taxis in both sexes. In larvae, both sexes prioritize feeding over exploration; correspondingly, the sexes have equal odr-10 expression and food attraction. Food deprivation, which transiently favors feeding over exploration in adult males, increases male food attraction by activating odr-10 expression. Furthermore, the weak expression of odr-10 in well-fed adult males has important adaptive value, allowing males to efficiently locate mates in a patchy food environment. CONCLUSIONS We find that modulated expression of a single chemoreceptor plays a key role in naturally occurring variation in the prioritization of feeding and exploration. The convergence of three independent regulatory inputs--somatic sex, age, and feeding status--on chemoreceptor expression highlights sensory function as a key source of plasticity in neural circuits.
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Affiliation(s)
- Deborah A Ryan
- Center for Neural Development and Disease, Department of Biomedical Genetics, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Renee M Miller
- Center for Neural Development and Disease, Department of Biomedical Genetics, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY 14642, USA; Department of Brain and Cognitive Sciences, University of Rochester, Rochester, NY 14642, USA
| | - KyungHwa Lee
- Center for Neural Development and Disease, Department of Biomedical Genetics, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Scott J Neal
- Department of Biology, National Center for Behavioral Genomics, Brandeis University, Waltham, MA 02454, USA
| | - Kelli A Fagan
- Center for Neural Development and Disease, Department of Biomedical Genetics, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Piali Sengupta
- Department of Biology, National Center for Behavioral Genomics, Brandeis University, Waltham, MA 02454, USA
| | - Douglas S Portman
- Center for Neural Development and Disease, Department of Biomedical Genetics, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY 14642, USA.
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20
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Octopamine neuromodulation regulates Gr32a-linked aggression and courtship pathways in Drosophila males. PLoS Genet 2014; 10:e1004356. [PMID: 24852170 PMCID: PMC4031044 DOI: 10.1371/journal.pgen.1004356] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 03/24/2014] [Indexed: 01/08/2023] Open
Abstract
Chemosensory pheromonal information regulates aggression and reproduction in many species, but how pheromonal signals are transduced to reliably produce behavior is not well understood. Here we demonstrate that the pheromonal signals detected by Gr32a-expressing chemosensory neurons to enhance male aggression are filtered through octopamine (OA, invertebrate equivalent of norepinephrine) neurons. Using behavioral assays, we find males lacking both octopamine and Gr32a gustatory receptors exhibit parallel delays in the onset of aggression and reductions in aggression. Physiological and anatomical experiments identify Gr32a to octopamine neuron synaptic and functional connections in the suboesophageal ganglion. Refining the Gr32a-expressing population indicates that mouth Gr32a neurons promote male aggression and form synaptic contacts with OA neurons. By restricting the monoamine neuron target population, we show that three previously identified OA-FruM neurons involved in behavioral choice are among the Gr32a-OA connections. Our findings demonstrate that octopaminergic neuromodulatory neurons function as early as a second-order step in this chemosensory-driven male social behavior pathway. To mate or fight? When meeting other members of their species, male fruit flies must determine whether a second fly is male or female and proceed with the appropriate behavioral patterns. The taste receptor, Gr32a, has been reported to respond to chemical messages (pheromones) that are important for gender recognition, as eliminating Gr32a function impairs both male courtship and aggressive behavior. Here we demonstrate that different subsets of Gr32a-expressing neuron populations mediate these mutually exclusive behaviors and the male Gr32a-mediated behavioral response is amplified through neurons that contain the neuromodulator octopamine (OA, an invertebrate equivalent of norepinephrine). Gr32a-expressing neurons connect functionally and synaptically with distinct OA neurons indicating these amine neurons may function as early as a second-order step in a chemosensory-driven circuit. Our results contribute to understanding how an organism selects an appropriate behavioral response upon receiving external sensory signals.
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21
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Mowrey WR, Bennett JR, Portman DS. Distributed effects of biological sex define sex-typical motor behavior in Caenorhabditis elegans. J Neurosci 2014; 34:1579-91. [PMID: 24478342 PMCID: PMC3905135 DOI: 10.1523/jneurosci.4352-13.2014] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Revised: 11/05/2013] [Accepted: 11/07/2013] [Indexed: 12/24/2022] Open
Abstract
Sex differences in shared behaviors (for example, locomotion and feeding) are a nearly universal feature of animal biology. Though these behaviors may share underlying neural programs, their kinematics can exhibit robust differences between males and females. The neural underpinnings of these differences are poorly understood because of the often-untested assumption that they are determined by sex-specific body morphology. Here, we address this issue in the nematode Caenorhabditis elegans, which features two sexes with distinct body morphologies but similar locomotor circuitry and body muscle. Quantitative behavioral analysis shows that C. elegans and related nematodes exhibit significant sex differences in the dynamics and geometry of locomotor body waves, such that the male is generally faster. Using a recently proposed model of locomotor wave propagation, we show that sex differences in both body mechanics and the intrinsic dynamics of the motor system can contribute to kinematic differences in distinct mechanical contexts. By genetically sex-reversing the properties of specific tissues and cells, however, we find that sex-specific locomotor frequency in C. elegans is determined primarily by the functional modification of shared sensory neurons. Further, we find that sexual modification of body wall muscle together with the nervous system is required to alter body wave speed. Thus, rather than relying on a single focus of modification, sex differences in motor dynamics require independent modifications to multiple tissue types. Our results suggest shared motor behaviors may be sex-specifically optimized though distributed modifications to several aspects of morphology and physiology.
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Affiliation(s)
| | | | - Douglas S. Portman
- Center for Neural Development and Disease
- Department of Biomedical Genetics, and
- Department of Biology, University of Rochester, School of Medicine and Dentistry, Rochester, New York 14642
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22
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PDF-1 neuropeptide signaling modulates a neural circuit for mate-searching behavior in C. elegans. Nat Neurosci 2012; 15:1675-82. [PMID: 23143519 PMCID: PMC3509246 DOI: 10.1038/nn.3253] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Accepted: 10/01/2012] [Indexed: 12/20/2022]
Abstract
Appetitive behaviors require complex decision-making, involving the integration of environmental stimuli and physiological needs. C. elegans mate searching is a male-specific exploratory behavior regulated by two competing needs: food versus reproductive appetite. Here we show that the Pigment Dispersing Factor Receptor (PDFR-1) modulates the circuit that encodes the male reproductive drive promoting male exploration upon mate-deprivation. PDFR-1 and its ligand PDF-1 stimulate mate searching in the male but not in the hermaphrodite. pdf-1 is required in the gender-shared interneuron AIM and the receptor acts in internal and external environment-sensing neurons of the shared nervous system (URY, PQR and PHA) to produce mate-searching behavior. Thus, the pdf-1/pdfr-1 pathway functions in non sex-specific neurons to produce a male-specific, goal-oriented exploratory behavior. Our results indicate that secretin neuropeptidergic signaling plays an ancient role in regulating motivational internal states.
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