Skip to Main content Skip to Navigation
Journal articles

Transmembrane Potential Polarization, Calcium Influx, and Receptor Conformational State Modulate the Sensitivity of the Imidacloprid-Insensitive Neuronal Insect Nicotinic Acetylcholine Receptor to Neonicotinoid Insecticides

Abstract : Neonicotinoid insecticides act selectively on insect nicotinic acetylcholine receptors (nAChRs). Recent studies revealed that their efficiency was altered by the phosphorylation/dephosphorylation process and the intracellular signaling pathway involved in the regulation of nAChRs. Using whole-cell patch-clamp electrophysiology adapted for dissociated cockroach dorsal unpaired median (DUM) neurons, we demonstrated that intracellular factors involved in the regulation of nAChR function modulated neonicotinoid sensitivity. DUM neurons were known to express two α-bungarotoxin-insensitive nAChR subtypes: nAChR1 and nAChR2. Whereas nAChR1 was sensitive to imidacloprid, nAChR2 was insensitive to this insecticide. Here, we demonstrated that, like nicotine, acetamiprid and clothianidin, other types of neonicotinoid insecticides, acted as agonists on the nAChR2 subtype. Using acetamiprid, we revealed that both steady-state depolarization and hyperpolarization affected nAChR2 sensitivity. The measurement of the input membrane resistance indicated that change in the acetamiprid-induced agonist activity was related to the receptor conformational state. Using cadmium chloride, ω-conotoxin GVIA, and (R,S)-(3,4-dihydro-6,7-dimethoxy-isoquinoline-1-yl)-2-phenyl-N,N-di-acetamide (LOE 908), we found that inhibition of calcium influx through high voltage-activated calcium channels and transient receptor potential γ (TRPγ) activated by both depolarization and hyperpolarization increased nAChR2 sensitivity to acetamiprid. Finally, using N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide hydrochloride (W7), forskolin, and cAMP, we demonstrated that adenylyl cyclase sensitive to the calcium/calmodulin complex regulated internal cAMP concentration, which in turn modulated TRPγ function and nAChR2 sensitivity to acetamiprid. Similar TRPγ-induced modulatory effects were also obtained when clothianidin was tested. These findings bring insights into the signaling pathway modulating neonicotinoid efficiency and open novel strategies for optimizing insect pest control
Document type :
Journal articles
Complete list of metadata

https://hal.inrae.fr/hal-02649387
Contributor : Migration Prodinra Connect in order to contact the contributor
Submitted on : Friday, May 29, 2020 - 11:56:39 AM
Last modification on : Friday, June 12, 2020 - 10:43:26 AM

Identifiers

Collections

Citation

Beatrice Bodereau-Dubois, Olivier List, Delphine Calas-List, Olivier Marques, Pierre-Yves Communal, et al.. Transmembrane Potential Polarization, Calcium Influx, and Receptor Conformational State Modulate the Sensitivity of the Imidacloprid-Insensitive Neuronal Insect Nicotinic Acetylcholine Receptor to Neonicotinoid Insecticides. Journal of Pharmacology and Experimental Therapeutics, American Society for Pharmacology and Experimental Therapeutics, 2012, 341 (2), pp.326-339. ⟨10.1124/jpet.111.188060⟩. ⟨hal-02649387⟩

Share

Metrics

Record views

29