Summary of smoking and nicotine

Smoking and nicotine
What is tobacco use disorder? What is nicotine?
 the name of nicotine addiction
 about 30% smokers become addicted
 more than 80% relapse after a year of stopping smoking
 nicotine is the substance in tobacco or vaping that causes a pleasurable effect
Why is nicotine so addictive? Why is addiction so easy?
 legal so we can use them easily
 also due to the triggers associated with it
What are triggers for smoking?
situations that trigger the urge to smoke
 drinking coffee
 taking breaks at work
 talking on the phone
 drinking alcohol
 driving your car
 spending time with friends
Where does nicotine work in the body?
 nicotine receptors: nicotinic acetylcholine receptors
 ligand gated ion channels
o so produce a fast signal
 widely distributed in the CNS e.g neuromuscular junction
 9 subunits identified
o alpha 7 and alpha4beta2 subtypes
How does nicotine produce its addictive properties?
 effect on endogenous opioids
o stimulate release of these opioids
o both onto GABAergic neurons in the VTA and NAcc
 nicotine receptors on dopamine neurons themselves
o when we take in nicotine these are stimulated
o dopamine neurons fire
o release dopamine in the NAcc
 stimulates glutamatergic inputs as well
o further stimulates diopamine cell bodies to release more dopamine at the
NAcc
How and why does nicotine tolerance occur?
 very rapidly
 fast desensitization of nicotinic receptors
o especially alpha4beta2
 half life is 2 hours
o inhail so straight into the blood stream
o buildup of nicotine over the day
o this changes the balance of how our nicotine receptors are working
o towards this inactive state over a prrolonged period of the day
o not getting the effect we need
o so increase the amount we smoke