Neonicotinoid insecticides subunits

In a recent study, resistance to the neonicotinoid insecticide, imidacloprid, in the brown plant hopper, Nilaparvata lugens, was found to be due to a point mutation at a conserved position in two nAChR subunits. As a result, it reduced the receptor binding of imidacloprid (Liu et al., 2005). 

Generally, insect nAChRs clearly vary with specificity of their interaction with neonicotinoid insecticides however, the appropriate subunit is unclear so far. An investigation that supports the hypothesis that there is a conserved neonicotinoid special sensitive subtype of the nAChR binding site in different insects like Musca domestica, D. melanogaster, Aphis craccivora, Myzus persicae has been discussed [97]. 

These examples indicate the complexity of insect nAChRs, which is difficult to understand. The considerable diversity of potential subunit combinations probably accounts for the multiplicity of distinctive pharmacological profiles in insect nAChRs. In that context, electrophysiology will play an essential role in determining the significance of certain subunit combinations in the MoA of neonicotinoid and further insecticidally active ligands. 

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