Mode of Action of Neonicotinoid Insecticides Imidacloprid and Thiacloprid to the Cockroach Pameα7 Nicotinic Acetylcholine Receptor

Abstract

The functional expression of the cockroach Pameα7 nicotinic acetylcholine receptor subunit has been previously studied, and was found to be able to form a homomeric receptor when expressed in Xenopus laevis oocytes. In this study, we found that the neonicotinoid insecticide imidacloprid is unable to activate the cockroach Pameα7 receptor, although thiacloprid induces low inward currents, suggesting that it is a partial agonist. In addition, the co-application or 5 min pretreatment with 10 µM imidacloprid increased nicotine current amplitudes, while the co-application or 5 min pretreatment with 10 µM thiacloprid decreased nicotine-evoked current amplitudes by 54% and 28%, respectively. This suggesting that these two representatives of neonicotinoid insecticides bind differently to the cockroach Pameα7 receptor. Interestingly, the docking models demonstrate that the orientation and interactions of the two insecticides in the cockroach Pameα7 nAChR binding pocket are very similar. Electrophysiological results have provided evidence to suggest that imidacloprid and thiacloprid could act as modulators of the cockroach Pameα7 receptors.

The Synergistic Effect of Thiamethoxam and Synapsin dsRNA Targets Neurotransmission to Induce Mortality in Aphis gossypii

“…In cholinergic synapses in insects, the excitatory neurotransmitter acetylcholine (ACh) is released presynaptically and binds to the postsynaptic receptor nAChR, causing opening of the ion channel for neurotransmission. Neonicotinoids can irreversibly bind to nAChR and block synaptic transmission at the postsynaptic membrane [ 1 , 2 , 64 ]. In contrast, the presynaptic action potentials are still evoked when the excitatory postsynaptic potentials are blocked by imidacloprid or clothianidin [ 65 , 66 ].…”

Physiological Responses of the Firefly Pyrocoelia analis (Coleoptera: Lampyridae) to an Environmental Residue From Chemical Pesticide Imidacloprid

“…In our study, persistent luminescence in the larvae of P. analis was observed after 12 h of exposure to imidacloprid. This phenomenon could be related to imidacloprid binding to the nAChRs, which caused the continuous conduction of nerve impulses ( Topal et al, 2017 ; Cartereau et al, 2021 ). However, some studies reported that bioluminescence could be an auxiliary oxygen detoxifying mechanism in fireflies ( Barros and Bechara, 1998 ; Dubuisson et al, 2004 ).…”

“…Several studies have documented that these neonicotinoids persist in the environment for a long time and the contents of neonicotinoid pesticides in different farmlands were all present at the ng/g level ( Li et al, 2018 ; Thompson et al, 2020 ). Imidacloprid can competitively bind to nicotinic acetylcholine receptors (nAChRs), and the postsynaptic nAChRs are blocked irreversibly, causing the continuous conduction of nerve impulses and thus producing lethal effects ( Matsuda et al, 2001 ; Cartereau et al, 2021 ). Apart from acting on target organisms, imidacloprid can be dispersed in other non-target organisms and accumulate in the environment by different types of applications ( Cloyd and Bethke, 2011 ; Goulson, 2013 ; Sharma et al, 2019 ; Singh and Leppanen, 2020 ).…”

An assessment of health risks posed by consumption of pesticide residues in fruits and vegetables among residents in the Kampala Metropolitan Area in Uganda

“…Fruits and vegetables samples were collected from key stages along the supply chain including farms (50), markets (50), street vendors (20), restaurants (20) and homes (20), totaling 160 samples. The detailed methodology used to collect the fruits and vegetable samples has been previously described [33].…”

“…However, they are neurotoxicants and have been associated with confusion, lacrimation and salivation [16] and also poorer development and asthma in children [17,18]. The mechanism of toxicity for neonicotinoids is based on selective binding and interaction with nicotinic acetylcholine receptor sites of a target organism causing paralysis that leads to death [19][20][21], and they have also been associated with development or neurological disorders [22] in humans.…”