Smoking addiction neurotransmission

What is nicotine addiction

Relying on vaping or cigarette smoking, craving for nicotine even though it is causing you harm

What is the role of dopamine receptors

Proteins in the brain that bind to dopamine. A neurotransmitter responsible for pleasure, motivation and motor control

What are the neurons in the are of the brain called

The ventral tagmental area (VTA) which have receptors on their surfaces which respond to dopamine molecules

What is dopamine to the brain

'Pleasure and reward chemical'

What molecules are able to attach to the dopamine receptors

Nicotine molecules

What happens when a smoker first takes a drag of a cigarette

Nicotine molecules reach these receptors very quickly (in seconds) which triggers the release of dopamine in a near by region called nucleus accumbens (NA). The feeling of the 'buzz' the smoker receives is rewarding due to the dopamine released

What are the 'reward areas' of the brain

Prefrontal cortex, nucleus accumbens and ventral tegmental area

What does nicotine increase the amount of

Dopamine

What does chronic tobacco use produce

Repeated dopamine surges which eventually desensitises the reward system making it less responsive to everyday stimuli. Nicotine turned the natural needs into tobacco needs

What happens as the body adapts to constant high levels of dopamine

More nicotine is required to achieve the same pleasurable effect

What can smoking cessation cause

Withdrawal systems (cravings, irritability, anxiety, depression, attention deficit, difficulty sleeping, increased appetite)

What is another substance that contributes to tobacco addiction

Acetaldehyde (in adolescence)

Does genetic makeup play a role in susceptibility to addiction

Yes

What genes are involved in the increased likelihood of nicotine addiction

-nicotine receptors (CHRNB3, CHRNA5)

-nicotine metabolism (CYP216)

- dopamine receptors (DRD2, DRD4)

-dopamine transport/metabolism (DAT, MAO)

-serotonin pathways

What does increased speed and amount of nicotine delivery cause

Addiction

How long do nicotine effects last

Only several minutes

What is tobacco use linked to

-premature death

-lung diseases and cancer

-cardiovascular diseases

Smoking during pregnancy = fetal growth retardation, withdrawal symptoms in infants, increased infant death and learning and behavioural problems

What are the treatments for tobacco addiction

-behavioural therapies

-nicotine replacement (nicotine patch/ gums)

Why are nicotine patches and gums good to treat tobacco addiction

Low addiction potential as they release nicotine slowly and in small amounts.

Helps reduce withdrawal symptoms

Reduces toxicity

What creates the dependence associated with smoking

Nicotine's interactions with certain parts of the brain

Research to support nicotine and addiction

Regulation theory - Stanley schachter (1977) gave light and heavy smokers cigarettes containing lower than usual amounts of nicotine. This means that the smokers would have lower levels of nicotine in their bloodstream than they were used to. As predicted by the nicotine regulation model, heavy smokers increased the level of smoking by 25% more than the light smokers did (18%) in order to make up the bigger nicotine deficit.

Research evidence against nicotine and addiction

-not everyone regulates nicotine level. Sal shiftman et al (1995) studied 'chippers' (people who smoke regularly bu do not become dependent) chippers' who smoked on average 5 a day showed little withdrawal symptoms and no compulsion to smoke again. They may have learned to smoke through observation of models rather than because of the rewarding dopamine hit