drugs

Question 1

cocaines effect

Answer 1

• stimulant effect on brains CNS, especially on the neurons of the brains main reward system

Question 2

how does cocaine have the effect on cns

Answer 2

• it alters synaptic transmission involving different neurotransmitters

Question 3

which neurotransmitters does cocaine effect

Answer 3

noradrenaline
serotonin
acetylcholine
dopamine

Question 4

which neurotransmitter does cocaine effect the most

Answer 4

dopamine

Question 5

cocaine increased release of dopamine
what does dopamine do

Answer 5

• a sense of pleasure

Question 6

where is dopamine released

Answer 6

reward centers of brain

Question 7

what does cocaine block the trip take of

Answer 7

dopamine

Question 8

how does cocaine block the trip take of dopamine

Answer 8

• by binding with dopamine transporter molecules on the terminal buttons in the presynaptic neurons
• These are responsible for recycling dopamine back into the neuron that produced it

Question 9

because cocaine blocks reuptake of dopamine what happens

Answer 9

• the synapse is flooded with surpless quantities of dopamine all available for binding with postsynaptic receptors
• this is why cocaine gives us a euphoric high

Question 10

long term effects of cocaine

Answer 10

• after repeated use dopamine receptors become downregulated
• this explains withdrawal and craving for the drug and higher doses needed to get the same effects

Question 11

downregulated

Answer 11

• fewer receptors are active
• some are damaged and shut down
• so the quantity of dopamine produced declines

Question 12

heroin effects

Answer 12

• depressant effects on cns slowing down its activity
• including activity of neurones involved in pain = why it’s an analgesic

Question 13

how is heroin taken

Answer 13

usually injected intravenously

Question 14

once heroin reaches the brain how is it processed

Answer 14

most of it has processed into morphine

Question 15

what does the morphine from the heroin bind do when it reaches the brain

Answer 15

• a specific opioid receptor at the synapse found in the cerebral cortex, limbic system and hypothalamus

Question 16

why do these specific opioid receptors exist in the brain for heroin and morphine

Answer 16

the cns has its own opioid system

Question 17

when heroin binds to the receptors of the natural opioid system what happens

Answer 17

endorphins and enkephalins are produced by the body as natural painkillers

Question 18

what type of drug is heroin

Answer 18

agonist

Question 19

why is heroin an agonist drug

Answer 19

it mimics the action of another natural biochemical

Question 20

long term effects of heroin

Answer 20

• downregulation on neural transmission
• opioid receptors on postsynaptic neurones are constantly binding with morphine molecules
• this desensitisises them to effects of the drug

Question 21

ecstasy

Answer 21

-cns stimulant that blocks reuptake of serotonin at the synapse

• causes neurons to increase their output of serotonin initially

Question 22

what does the activity of ecstasy or mdma do ?

Answer 22

create a double whammy of serotonin enhancement

• greater quantities are made available in the synapse for binding to post synaptic receptors

Question 23

evaluation - supporting points

Answer 23

• research supporting role of dopamine
• application to better treatments to addiction
• controlled experiments
• support from observational studies
• scientific evidence

Question 24

drug evaluation points - drawbacks

Answer 24

• validity using non human animal studies
• limitations in studying synaptic transmission
• ethical and practical limitations
• oversimplifies brain complexity

Question 25

scientific evidence - evaluation

Answer 25

- research is taken from multiple studies and support the same conclusions - reinforced theory as it has multiple scientific backings - more credible

Question 26

oversimplifies brain complexity - evaluation

Answer 26

- brain has multiple neurotransmitters interacting - reducing effects to only dopamine ignores these - oversimplifies how drugs affect CNS

Question 27

research supporting role of dopamine - evaluation

Answer 27

- supports view that cocaines effects are due to activity of dopamine in brains reward system

Question 28

research supporting role of dopamine - procedure

Answer 28

- mesocortiolimbic pathway of mice brains were deliberately damaged - so neuron can’t produce levels of dopamine usually associated with reward - when this is done mice can’t intravenously self administer cocaine - this doesn’t occur when the lesions are performed in other areas of the mice brain

Question 29

validity using non human animal studies - evaluation

Answer 29

- mainly non human animal studies used to understand drug effects in human CNS transmission - human brain is more complex than animal brains

Question 30

how are human brains more complicated than animal brains and oversimplified

Answer 30

- isolating effects of 1 neurotransmitter oversimplifies process - it’s unlikely complexity of recreational drugs effect on transmission is due to one mode of action - interactions of dopamine with other neurotransmitter systems aren’t well understood - using non human animals should be taken cautiously

Question 31

how can effects of drugs be taken from humans also

Answer 31

pet scans - which show similar results to the animal results

Question 32

evaluation - application to better treatments for addiction

Answer 32

- as our knowledge on effect of CNS grows more treatments for addiction become available

Question 33

how are treatments for heroin created

Answer 33

- once identified as an agonist which binds to opiate receptors - other drugs were developed with a reverse mode of action

Question 34

what treats addiction of heroin

Answer 34

naloxone

Question 35

naloxone

Answer 35

- doesn’t produce a rewarding euphoria associated with heroin use so can help manage withdrawal process and reduce symptoms