L.P.N.F. Explanations for nicotine addiction

Question 1

What are the explanations for nicotine addiction

Answer 1

• Brain neurochemistry
• learning theory

Question 2

define neurochemistry

Answer 2

relating to chemicals in the brain that regulate biological and psychological functioning

Question 3

explain what dopamine is

Answer 3

Dopamine is a neurotransmitter that generally has an excitatory effect and is associated with the sensation of pleasure. Unusually high levels are associated with SZ and unusually low levels are associated with Parkinson’s disease.

Question 4

define initiation

Answer 4

refers to the process where individuals start to be come addicted

Question 5

define maintainance

Answer 5

is the process whereby people continue to behave addictively even in the face of adverse consequences

Question 6

define relapse

Answer 6

the process whereby individuals who have managed to give up their addictive habits start to show signs and symptoms of the behaviour

Question 7

Explain how nicotine produces dopamine

Answer 7

The neurotransmitter ACh plays a key role in nervous sytem activity so there are may receptors on the surface of neurons in the CNS. One type of ACh receptors are nAChR (nicotine ACh receptors). These are different in that they can be activated by ACh or nicotine.
When nAChRs are activated by nicotine molecules, the neuron transmits dopamine.

Question 8

What happens when a nAChR is activated by nicotine molecules and the neuron transmits dopamine

Answer 8

The neuron then shuts down and temorarily cannot respond to any neurotransmitters. It is desensitised which leads to downregulation

Question 9

define downregulation in nicotine addiction

Answer 9

a reduction in the number of active neurons because fewer of them are available

Question 10

Why does nicotine create such a pleasurable effect

Answer 10

The nAChRs are concentrated in an area of the brain that when they are stimulates by nicotine the dopamine is transmitted along the mesolimbic pathway to the nucleus accumbens which triggers the release of more dopamine into the frontal cortex.
Dopamine is also transmitted along the mesocortical pathway to be directly released in the frontal cortex.

Question 11

Why are the mesolimbic and mesocortical pathways so important for nicotine addiction

Answer 11

these pathways are part of the brain’s dopamine reward system. Nicotine powerfully activates this system which results in pleasurable effects. These effects become associated with smoking through operant conditioning.

Question 12

explain (biologically) the process of upregulation in relation to nicotine addiction

Answer 12

As long as a person is smoking nAChRs are continuallly desensitised. When a person doesnt smoke for a prolonged period (i.e. when they sleep at night) nicotine leaves their body. This is when the nAChRs begin to fuction again so dopamine neurons resensitise and become available (upregulation).

Question 13

explain (biologically) withdrawal in relation to nicotine addiction

Answer 13

During upregulation the person starts experiencing withdrawal from lack of nicotine. During resensitisation nAChRs become overstimulated by ACh (because their is no nicotine to bind with them). nAChRs are at their most sensitive, which is why smokers describe the first cigarette as the most enjoyable because it strongly reactivates the dopamine reward system.

Question 14

What causes dependence for smokers (biologically)

Answer 14

Smokers avoid unpleasant physiological and psychological withdrawal states by having another cigarette but this results in a continuous cycle of downregulation in the day and upregulation at night which creates long-term desensitisation of nAChRs.

Question 15

What causes tolerance for smokers (biologically)

Answer 15

Continuous exposure of nAChRs to nicotine causes permanent changes to brain neurochemistry where the number of active receptors decreases. As this develops smokers have to smoke more to get the same effects.