Explanations For Nicotine Addiction Flashcards
What kind of explanation is brain neurochemistry?
A biological explanation
What is nAChR’s?
It is a subtype of the neurotransmitter Acetycholine (ACh) that’s specific to nicotine.
What happens when nAChR’s are activated?
It can be activated by either ACh or nicotine. It will transmit dopamine and then shutdown (desensitise) which leads to down regulation (decrease in active neurons).
How does it create pleasurable effects?
nAChR’s found in Ventral tegmental area (VTA). When stimulated by nicotine, dopamine is transmitted via mesolimbic pathway to the nucleus accumbens (NA) where more dopamine released and goes to the frontal cortex. Dopamine also goes via the mesocortical pathway and released directly to frontal cortex.
What are the 2 pathways to the frontal cortex?
Mesolimbic and Mesocortical pathway
What are the pathways also know as?
The brains dopamine reward system.
How does withdrawal work?
It’s the period where there is no nicotine present which means that the nAChR’s are resensitised (working) which leads to up regulation and is over stimulated by ACh.
What role does Dependence and tolerance have in nicotine addiction?
Because of dependence and tolerance smoker would avoid withdrawal symptoms by smoking again. This is cycle of up + down regulation, leads to long-term desensitisation of nAChR’s and to tolerance.
What effect will it have on the brains neurochemistry?
There will be a permanent negative change as there will be a decrease in active neurons.
Evaluation: Research support
+ McEvoy et al (1995) - smoking in schizophrenic people who tooke a dopamine antagonist drug. Found if took the drug they increased smoking as a self medication to increase their dopamine level.
Evaluation: Research support Counter
- Limited explanation, other Neurochemical systems involved. Watkins et al (2000)
Evaluation: Real world application
+ leads to treatments. Example: nicotine replacement therapy (NRT), it releases controlled levels of nicotine and allows for the smoker to withdraw safely and efficiently.
Evaluation: Withdrawal symptoms
- Not fully explained/correlated to blood nicotine levels. Gilbert (1995) - depends on environment and personality, Example: increased neuroticism = worse withdrawal symptoms
Evaluation Xtra: Determinism
Neurochemistry suggest addiction is inevitable due to biological factors but some people show no withdrawal symptoms which means it is not inevitable - shiffman + patty (2006)
