Mode of Action
Neonicotinoids, like nicotine, are nicotinic acetylcholine receptor agonists. This receptor is normally activated by the neurotransmitter acetylcholine. In mammals, these receptors are located in both the central and peripheral nervous systems. In insects the receptors are limited to the CNS. While low to moderate activation of these receptors causes nervous stimulation, high levels overstimulate and block the receptors. This receptor blockage causes paralysis and death. Normally, acetylcholine is broken down by acetylcholinesterase to terminate signals from these receptors. However, acetylcholinesterase cannot break down neonicotinoids, and the binding is irreversible. Because most neonicotinoids bind much more strongly to insect neuron receptors than to mammal neuron receptors, these insecticides are selectively more toxic to insects than mammals.
Read more about this topic: Neonicotinoid
Famous quotes containing the words mode of, mode and/or action:
“The mode of clearing and planting is to fell the trees, and burn once what will burn, then cut them up into suitable lengths, roll into heaps, and burn again; then, with a hoe, plant potatoes where you can come at the ground between the stumps and charred logs; for a first crop the ashes suffice for manure, and no hoeing being necessary the first year. In the fall, cut, roll, and burn again, and so on, till the land is cleared; and soon it is ready for grain, and to be laid down.”
—Henry David Thoreau (1817–1862)
“A man of genius has a right to any mode of expression.”
—Ezra Pound (1885–1972)
“The curse of me & my nation is that we always think things can be bettered by immediate action of some sort, any sort rather than no sort.”
—Ezra Pound (1885–1972)