The effect of recreational drugs on the transmission process in the CNS

Question 1

Define “recreational drugs”.

Answer 1

Drugs taken without medical justification for their psychoactive effects, in the belief that occasional use is not habit-forming or addictive

Question 2

Define “drug addiction”.

Answer 2

The positive responses of the reward system in the brain causing an individual to be reliant on a drug for normal functioning

Question 3

Define the “Dopamine Reward Pathway”.

Answer 3

The structures and neurones in the brain associated with the neurotransmitter dopamine to cause feelings of reward

Question 4

Define “desensitisation”.

Answer 4

Requiring a higher concentration or dosage of a drug to cause the same feeling due to a loss of response at the synaptic level

Question 5

What is the biological explanation for drug addiction? (5 points)

Answer 5

Recreational drugs often activate the limbic system of the brain

It consists of the hypothalamus, hippocampus and amygdala - involved in regulating arousal, emotions and mood

Stimulation of the Dopamine reward pathway as part of the limbic system causes people to associate positive emotions with drug-taking

This can then lead to desensitisation at the synaptic level

In extreme cases, overuse of recreational drugs can lead to addiction

Question 6

What is the biological explanation for the emotions experienced when on drugs? (2 points)

Answer 6

Stimulants like cocaine cause amplified signaling at the synaptic level, leading to euphoric emotions and the feeling of a ‘high’

When a person takes recreational drugs they are likely to feel euphoric emotions followed by dysphoria, a period of anxiety or dissatisfaction

Question 7

What are the 4 drugs you have to know about for Edexcel A-Level Psychology?

Answer 7

Nicotine
Cocaine
Alcohol
Cannabis

Question 8

What is nicotine and how does it affect synaptic transmission? (4 points)

Answer 8

Psychoactive component of tobacco

Acts as an agonist of nicotinic acetylcholine receptors

Binds to them and initiates an action potential, increasing neurotransmission

Its rewarding and addictive abilities link to increased dopamine release in the nucleus accumbens reward pathway of the brain

Question 9

What is cocaine and how does it affect synaptic transmission? (2 points)

Answer 9

Strong recreational stimulant drug

Increases energy, alertness, euphoria and heart rate

Question 10

How does cocaine affect synaptic transmission? (3 steps)

Answer 10

1. Blocks reuptake protein pumps which normally remove monoamine neurotransmitters from the synapse
2. Causes an increase in monoamine neurotransmitters like dopamine and serotonin in the synapse
3. Leads to continual depolarisation and stimulation of action potentials

Question 11

How does alcohol affect synaptic transmission? (3 points)

Answer 11

Temporarily boosts serotonin levels - makes people feel happier

Increases the inhibitory action of GABA in the long-term - post-synaptic neurone hyperpolarises

Action potentials and neuronal transmission decreased - slows down reactions

Question 12

What is GABA? (2 points)

Answer 12

An inhibitory neurotransmitter that reduces action potentials

Does this by causing hyperpolarisation in the post-synaptic membrane with the influx of Cl-ions

Question 13

How does cannabis affect synaptic transmission? (4 points)

Answer 13

THC binds to CB1 cannabinoid receptors - is a partial agonist of CB1 receptors in the:

Cerebral cortex - causes cognitive effects

Cerebellum - causes sedative effects

Brainstem - causes analgesic (pain relief) effects

Question 14

What is THC? (2 points)

Answer 14

Active ingredient found in marijuana

Causes euphoria, sedation and impaired cognitive function

Question 15

What are the 4 types of effects of THC depending on dosage?

Answer 15

Small doses - sedates

Moderate doses - stimulates

Large doses - acts as a hallucinogen

Very large doses - may cause psychotic-like symptoms

Question 16

What are the 5 evaluation points for the implications of recreational drugs on synaptic neurotransmission as a neurobiological explanation?

Answer 16

Supporting:
Strengths - Benowitz (2009) & Varenicline

Application - Manzanares (2006)

Refuting:
Credibility - Lewis et al (2020) and Allen & Stevens (1994)

Other explanations - Genetics

Debates - Freud

Question 17

What is Varenicline? (2 points)

Answer 17

A synthetic smoking cessation tablet and partial agonist at nicotinic receptors

Causing dopamine release to create the same positive reinforcement felt when smoking tobacco

Question 18

How is Benowitz (2009) a strength of the implications of recreational drugs on synaptic neurotransmission as a neurobiological explanation? (3 points)

Answer 18

Found that nicotine binds to nicotinic receptors in the brain to facilitate neurotransmitter release

Has led to the development of new treatment options for tobacco addiction including nicotine replacement therapy

The neurobiological explanation of recreational drugs can be used for the benefit of human understanding

Question 19

How does Lewis et al (2020) refute the credibility of the implications of recreational drugs on synaptic neurotransmission as a neurobiological explanation? (3 points)

Answer 19

Lack of generalisability despite empirical research demonstrating a link between cocaine and D2 dopamine receptors

Lewis et al (2020) found that cocaine causes elevated dopamine levels and inhibition of striatal acetylcholine signalling in male mice

Difficult to generalise findings from animal models to human behaviour - rats possess simpler CNS and brain anatomy than humans

Question 20

How does Allen & Stevens (1994) refute the credibility of the implications of recreational drugs on synaptic neurotransmission as a neurobiological explanation? (3 points)

Answer 20

Found that over 50% of presynaptic nerve impulses failed to evoke a postsynaptic response in a hippocampal cell slice

This was due to conduction failures - questionable reliability

Empirical research studies of recreational drugs and neurotransmission are not entirely falsifiable - reduced credibility

Question 21

How is genetics an alternate explanation for the implications of recreational drugs on synaptic neurotransmission as a neurobiological explanation? (2 points)

Answer 21

Cloninger’s (1970) studies of MZ twins showed that if one twin had an addiction, the other twin was likely to also have an addiction

Further twin studies have consistently found that MZ twins are more likely to both have an addiction than DZ twins

Question 22

Is there room for debate on the implications of recreational drugs on synaptic neurotransmission as a neurobiological explanation? (3 points)

Answer 22

Neurobiological explanations remain biologically reductionist - they fail to account for individual differences, including:
+ Personality
+ Free will to choose
+ Learning how to use recreational drugs in the environment

Freud suggests that recreational drug use is driven by a desire to escape from past traumatic experiences and to seek pleasure - can become a source of addiction

Question 23

How does Manzanares (2006) support the implications of recreational drugs on synaptic neurotransmission as a neurobiological explanation being applicable to real life? (3 points)

Answer 23

Demonstrated the role of THC and cannabinoid receptor agonists in alleviating acute and chronic pain episodes

Despite high doses of cannabis causing hallucinogenic effects, preclinical and clinical studies have suggested lower doses may be useful in treating diseases involving acute or chronic pain

Neurobiological explanations have important applications for society as medicinal treatments