title: Trans-generational desensitization and within-generational resensitization of a sucrose-best neuron in the polyphagous herbivore Helicoverpa armigera (Lepidoptera: Noctuidae).
abstract: Dietary exposure of insects to a feeding deterrent substance for hours to days can induce habituation and concomitant desensitization of the response of peripheral gustatory neurons to such a substance. In the present study, larvae of the herbivore Helicoverpa armigera were fed on diets containing either a high, medium or low concentration of sucrose, a major feeding stimulant. The responsiveness of the sucrose-best neuron in the lateral sensilla styloconica on the galea was quantified. Results showed the response of the sucrose-best neuron exposed to high-sucrose diets decreased gradually over successive generations, resulting in complete desensitization in the 5thand subsequent generations. However, the sensitivity was completely restored in the ninth generation after neonate larvae were exposed to low-sucrose diet. These findings demonstrate phenotypic plasticity and exclude inadvertent artificial selection for low sensitivity to sucrose. No significant changes were found in the sensitivity of caterpillars which experienced low- or medium-sucrose diets over the same generations. Such desensitization versus re-sensitization did not generalise to the phagosimulant myo-inositol-sensitive neuron or the feeding deterrent-sensitive neuron. Our results demonstrate that under conditions of high sucrose availability trans-generational desensitization of a neuron sensitive to this feeding stimulant becomes more pronounced whereas re-sensitization occurs within one generation.
authors.affiliation: The Institute of Chemical Ecology, Henan Agricultural University, Zhengzhou, 450002, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Ma
authors.affiliation: The Institute of Chemical Ecology, Henan Agricultural University, Zhengzhou, 450002, China.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Li
authors.affiliation: The Institute of Chemical Ecology, Henan Agricultural University, Zhengzhou, 450002, China.
authors.forename: Qingbo
authors.initials: Q
authors.lastname: Tang
authors.affiliation: The Institute of Chemical Ecology, Henan Agricultural University, Zhengzhou, 450002, China.|Zhengzhou City River Management Office, Zhengzhou, 450006, China.
authors.forename: Xuening
authors.initials: X
authors.lastname: Zhang
authors.affiliation: The Institute of Chemical Ecology, Henan Agricultural University, Zhengzhou, 450002, China.
authors.forename: Xincheng
authors.initials: X
authors.lastname: Zhao
authors.affiliation: The Institute of Chemical Ecology, Henan Agricultural University, Zhengzhou, 450002, China.
authors.forename: Fengming
authors.initials: F
authors.lastname: Yan
authors.affiliation: Laboratory of Entomology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands.
authors.forename: Joop J A
authors.initials: JJ
authors.lastname: van Loon
mesh_terms: D000818:Animals; D004032:Diet / Q000379:methods; D060434:Herbivory / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D007814:Larva / Q000187:drug effects / Q000502:physiology; D007915:Lepidoptera / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D058618:Sensilla / Q000187:drug effects / Q000502:physiology*; D013395:Sucrose / Q000008:administration & dosage*; D013549:Sweetening Agents / Q000008:administration & dosage*; D013649:Taste / Q000187:drug effects*
chemical_list: D013549:Sweetening Agents; D013395:Sucrose