Biology of drugs and addicition

Question 1

what are psychoactive drugs?

Answer 1

drugs that have an effect on the central nervous system

Question 2

what’s the reward pathway?

Answer 2

limbic system- sensitive dopamine, GABA, glutamate- whenever we do something ‘pleasurable’ these chemicals are released and activate this area

Question 3

What did Olds and Milner (1954) test and find?

Answer 3

• showed that there were probably pleasure centres in the brain-normal part of our motivation system
• rats would press a lever to receive reward of mild electrical stimulation to this part of the brain
• they would continue to press lever in preference to other possible rewards-food,drink,sexual activity- and even cross a grid of painful electrical currents to reach lever and receive pleasurable stimulation

Question 4

How do drugs work in general?

Answer 4

-cause a change to how neurotransmitters work either:
increasing dopamine levels in reward areas/blocking re-uptake(more dopamine hovers around increasing levels)
increase/decrease other neurotransmitters e.g GABA

Question 5

What is desensitisation?

Answer 5

if receptor is constantly stimulated by extra neurotransmitters than it will have a diminished response- causing you to take more drugs

Question 6

What is withdrawal?

Answer 6

group of symptoms that occur upon abrupt discontinuation or decrease in intake of medications or recreational drugs

Question 7

name 3 symptoms of withdrawal

Answer 7

shaking
sweating
jumpiness/irritability

Question 8

name 3 signs of addiction

Answer 8

cravings
withdrawal symptoms
physical dependence

Question 9

describe how cocaine works with the synaptic transmission

Answer 9

-blocks reuptake of neurotransmitters (serotonin,dopamine, norepinphrine)
binds transporters-normally remove excess of these neurotransmitters from synaptic gap- cocaine prevents these from being absorbed by neurons that released them= increased concentration in synapses=natural effect of dopamine on post-synaptic neurons is amplified

Question 10

describe how heroine works with the synaptic transmission

Answer 10

opioid drug made from morphine
when opioids bind to opiate-specific receptors within brain- able to decrease body’s perception of pain and elevate mood by increasing levels of dopamine
when body is introduced to heroin, it floods with opioids=high levels of dopamine

Question 11

describe how alcohol works with the synaptic transmission

Answer 11

alcohol suppresses release of glutamte slowing down the brain’s highways
GABA reduces energy leves and calms everything down- alcohol increases the effects of GABA - suppresses excitatory neurotransmitter glutamate and increases inhibitory neurotransmitter GABA–creates depressant effect
-increases level of dopamine