Nicotine addiction Flashcards
Smoking maintenance: Increased dopamine activity
1.Nicotine specific NACR receptors which increases alertness, memory function and learning
- Causes a rise in dopamine in the ventral tegmental area which is important for reward circuitry which has lots of NACR receptors
- VTA activity caused by nicotine is then projected to nucleus accumbens, produces nicotine located on the mesolimbic dopamine pathway
- Nucleus accumbens is a primary reward centre, increased activity causes smoking as pleasurable
- Nucleus accumbens produces more dopamine and stimulates endorphins that reduce GABA activity which produces more dopamine
What is downregulation?
Specific NACR receptors become inactive and unavailable due to tolerance. Lethargy and anxiety
What is upregulation?
When smokers go without nicotine for a while, allows more nicotine receptors to become functional again
Paterson et al (2002)
Experimented with an epilepsy drug which reduces dopamine after nicotine which reduces addictive properties without major side effects
Nerin and Jane (2007)
The onset of smoking addiction is significantly different between the sexes e.g. women smoke much later than men
Survey by NIDA (2000)
90% of US smokers claimed they took up the habit as a teenager and most attributed this to watching friends and family members
Immediate reinforcement
25% of nicotine reaches the brain in less than 10 seconds validates the idea that immediate reinforcement has more precedence over long term consequences
Milton et al (2008)
Young smokers identified peer influence as an important factor in smoking. Social modelling and interaction, peer acceptance acts like reinforcement