The actions of the neonicotinoid imidacloprid on cholinergic neurons of Drosophila melanogaster.

Journal article

The neonicotinoid insecticide imidacloprid is an agonist on insect nicotinic acetylcholine receptors (nAChRs). We utilised fura-2-based calcium imaging to investigate the actions of imidacloprid on cultured GFP-tagged cholinergic neurons from the third instar larvae of the genetic model organism Drosophila melanogaster. We demonstrate dose-dependent increases in intracellular calcium ([Ca2+]i) in cholinergic neurons upon application of imidacloprid (10 nM-100 muM) that are blocked by nAChR antagonists mecamylamine (10 microM) and alpha-bungarotoxin (alpha-BTX, 1 microM). When compared to other (untagged) neurons, cholinergic neurons respond to lower concentrations of imidacloprid (10-100 nM) and exhibit larger amplitude responses to higher (1-100 microM) concentrations of imidacloprid. Although imidacloprid acts via nAChRs, increases in [Ca2+]i also involve voltage-gated calcium channels (VGCCs) in both groups of neurons. Thus, we demonstrate that cholinergic neurons express nAChRs that are highly sensitive to imidacloprid, and demonstrate a role for VGCCs in amplifying imidacloprid-induced increases in [Ca2+]i.

Authors: Jepson, J; Brown, L; Sattelle, D

• Journal: Invertebrate neuroscience : IN
• Volume: 6
• Issue: 1
• Pages: 33-40
• Publication date: 2006-03-01
• DOI: 10.1007/s10158-005-0013-8
• EISSN: 1439-1104
• ISSN: 1354-2516
• Language: English
• Keywords: Microscopy, Fluorescence; Drosophila melanogaster; Receptors, Nicotinic; Animals, Genetically Modified; Cells, Cultured; Animals; Fura-2; Neurons; Imidazoles; Calcium Channels; Nitro Compounds; Acetylcholine; Insecticides