Symposium overview: Mechanism of action of nicotine on neuronal acetylcholine receptors, from molecule to behavior - Abstracts

Nicotine has long been known to interact with nicotinic acetylcholine (ACh) receptors since Langley used it extensively to chart sympathetic ganglia a century ago. It has also been used as an effective insecticide. However, i t was not until the 1990s that the significance of nicotine was increasingl y recognized from the toxicological, pharmacological, and environmental poi nts of view. This is partly because studies of neuronal nicotinic ACh recep tors are rapidly emerging from orphan status, fueled by several lines of re search. Since Alzheimer's disease is known to be associated with down-regul ation of cholinergic activity in the brain, a variety of nicotine derivativ es are being tested and developed for treatment of the disease. Public awar eness of the adverse effects of nicotine has reached the highest level rece ntly, Since insect resistance to insecticides is one of the most serious is sues in the pest-control arena, it is an urgent requirement to develop new insecticides that act on target sites not shared by the existing insecticid es. The neuronal nicotinic ACh receptor is one of them, and new nicotinoids are being developed, Thus, the time is ripe to discuss the mechanism of ac tion of nicotine from a variety of angles, including the molecular, physiol ogical, and behavioral points of view. This Symposium covered a wide area o f nicotine studies: genetic, genomic, and functional aspects of nicotinic A Ch receptors were studied, as related to anthelmintics and insecticides; in teractions between ethanol and nicotine out the ACh receptor were analyzed, in an attempt to explain the well-known heavy drinker-heavy smoker correla tion; the mechanisms that underlie the desensitization of ACh receptors wer e studied as related to nicotine action; selective pharmacological profiles of nicotine, and descriptions of some derivatives were described; and chro nic nicotine infusion effects on memory were examined using animal models.