title: Low doses of a neonicotinoid insecticide modify pheromone response thresholds of central but not peripheral olfactory neurons in a pest insect.
abstract: Insect pest management relies mainly on neurotoxic insecticides, including neonicotinoids, leaving residues in the environment. There is now evidence that low doses of insecticides can have positive effects on pest insects by enhancing various life traits. Because pest insects often rely on sex pheromones for reproduction, and olfactory synaptic transmission is cholinergic, neonicotinoid residues could modify chemical communication. We recently showed that treatments with different sublethal doses of clothianidin could either enhance or decrease behavioural sex pheromone responses in the male moth, Agrotis ipsilon. We investigated now effects of the behaviourally active clothianidin doses on the sensitivity of the peripheral and central olfactory system. We show with extracellular recordings that both tested clothianidin doses do not influence pheromone responses in olfactory receptor neurons. Similarly, in vivo optical imaging does not reveal any changes in glomerular response intensities to the sex pheromone after clothianidin treatments. The sensitivity of intracellularly recorded antennal lobe output neurons, however, is upregulated by a lethal dose 20 times and downregulated by a dose 10 times lower than the lethal dose 0. This correlates with the changes of behavioural responses after clothianidin treatment and suggests the antennal lobe as neural substrate involved in clothianidin-induced behavioural changes.
authors: Neuroéthologie-RCIM, INRA-Université d'Angers, UPRES EA 2647 USC INRA 1330, 42, rue Georges Morel, 49071 Beaucouzé Cedex, France.
authors: Kaouther K
authors: KK
authors: Rabhi
authors: Institut d'Ecologie et des Sciences de l'Environnement de Paris (iEES-Paris), UMR 1392, Département d'Ecologie Sensorielle, INRA, Route de Saint-Cyr, 78026 Versailles Cedex, France.
authors: Nina
authors: N
authors: Deisig
authors: Institut d'Ecologie et des Sciences de l'Environnement de Paris (iEES-Paris), UMR 1392, Département d'Ecologie Sensorielle, INRA, Route de Saint-Cyr, 78026 Versailles Cedex, France.
authors: Elodie
authors: E
authors: Demondion
authors: Neuroéthologie-RCIM, INRA-Université d'Angers, UPRES EA 2647 USC INRA 1330, 42, rue Georges Morel, 49071 Beaucouzé Cedex, France.
authors: Julie
authors: J
authors: Le Corre
authors: Neuroéthologie-RCIM, INRA-Université d'Angers, UPRES EA 2647 USC INRA 1330, 42, rue Georges Morel, 49071 Beaucouzé Cedex, France.
authors: Guillaume
authors: G
authors: Robert
authors: Neuroéthologie-RCIM, INRA-Université d'Angers, UPRES EA 2647 USC INRA 1330, 42, rue Georges Morel, 49071 Beaucouzé Cedex, France.
authors: Hélène
authors: H
authors: Tricoire-Leignel
authors: Institut d'Ecologie et des Sciences de l'Environnement de Paris (iEES-Paris), UMR 1392, Département d'Ecologie Sensorielle, INRA, Route de Saint-Cyr, 78026 Versailles Cedex, France.
authors: Philippe
authors: P
authors: Lucas
authors: Neuroéthologie-RCIM, INRA-Université d'Angers, UPRES EA 2647 USC INRA 1330, 42, rue Georges Morel, 49071 Beaucouzé Cedex, France.
authors: Christophe
authors: C
authors: Gadenne
authors: Neuroéthologie-RCIM, INRA-Université d'Angers, UPRES EA 2647 USC INRA 1330, 42, rue Georges Morel, 49071 Beaucouzé Cedex, France sylvia.anton@angers.inra.fr.
authors: Sylvia
authors: S
authors: Anton
mesh_terms: D000818:Animals; D002490:Central Nervous System / Q000187:drug effects / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D006146:Guanidines / Q000494:pharmacology*; D007306:Insecticides / Q000494:pharmacology*; D008297:Male; D009036:Moths / Q000187:drug effects* / Q000502:physiology; D000073943:Neonicotinoids; D018034:Olfactory Receptor Neurons / Q000187:drug effects / Q000502:physiology; D012724:Sex Attractants / Q000378:metabolism*; D012726:Sexual Behavior, Animal / Q000187:drug effects; D013844:Thiazoles / Q000494:pharmacology*
chemical_list: D006146:Guanidines; D007306:Insecticides; D000073943:Neonicotinoids; D012724:Sex Attractants; D013844:Thiazoles; C480342:clothianidin
keywords: antennal lobe; calcium imaging; electrophysiology; moth; olfactory receptor neurons; sublethal insecticide dose