How difficult is it to quit smoking? Many smokers attempt to quit smoking, but relapse. For some smokers, such as my dad, they can't picture a day without smoking a cigarette. Why do nicotine and cigarettes have such a strong hold on their users? In a recent Science daily article, it was reported that an FDA-approved drug for Alzheimer's disease could be a potential drug used to aid in the cessation of smoking. How can an Alzheimer's drug help smokers quit? According to the Science Daily article, researchers at the University of Pennsylvania are working on re-purposing two Alzheimer's medications, galantamine and donepezil. Galantamine and donepezil are acetylcholinesterase inhibitors which delay or reduce cognitive impairments. In other words, these two medications help Alzheimer's patients improve their thinking and cognition.
Why did researchers at UPenn decide to study galantamine and donepezil as potential "quit smoking" medication? The main driving force for the researchers was the nicotine withdrawal symptoms described by those attempting to quit smoking. Withdrawal symptoms included forgetfulness, disorientation and an overall decrease in emotional control, memory learning, organization and planning. The premise behind this study is that the cognitive impairments during nicotine withdrawal could be combated by Alzheimer's medications. But, why focus on these symptoms? It is the withdrawal symptoms that may lead an individual to relapse and start smoking cigarettes again. Perhaps, if the nicotine withdrawal symptoms are reduced, then those attempting to quit smoking will permanently stop smoking. The researchers reported that clinical trial participants smoked 2.3 less cigarettes daily.
Nicotine addiction changes the wiring of neurons with the brain. Dr. Daniel McGehee and colleagues at the University of Chicago study the effects of nicotine on long-term potentiation (LTP). Long-term potentiation is the strengthening of synaptic transmission between two neurons. LTP has implications in the formation and retrieval of memory. Dr. McGehee studied that effects of nicotine on dopaminergic neurons, which are "excitatory" neurons, in the ventral tegmental area (VTA) of the brain. Dr. McGehee reported that nicotine changed the synaptic strength of the dopaminergic (DA) neurons. Nicotine enhanced the excitatory input to the DA neurons in the ventral tegmental area. Futhermore, the changes induced by nicotine were long-term. It is important to note that the ventral tegmental area is a key player in addiction behavior. Perhaps, the strengthening of the synapses in the VTA are forming the foundation for "smoking" memory. My husband recently quit smoking after 10 years of being a cigarette smoker. He has not smoked a cigarette in over two months, but he occasionally smells the smell of cigarettes. I wonder if his VTA DA neurons are experiencing long-term depression after overcoming his nicotine addiction (for now).
Sources: "FDA-approved Alzheimer's drug could help smokers quit." https://www.sciencedaily.com/releases/2016/02/160218200219.htm
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