The Effect Of Recreational Drugs

Question 1

What is an agonist drug?

Answer 1

• A drug which mimics the effect of the neurotransmitter
• they bind to receptors to excite the neuron, so it seems more of a natural NT is released, and increase the action potentials

Question 2

What is an antagonist drug?

Answer 2

• reduces or stops the effect of the neurotransmitter

- it binds to the receptors blocking them, to stop/slow down the message being passed on

Question 3

What is a reuptake inhibitor?

Answer 3

• blocks the reuptake of the neurotransmitter

- means more neurotransmitter stays in the synapse increasing its action

Question 4

How does the recreational drug heroin impact neurotransmission?

Answer 4

• it binds to the presynaptic neurons that use dopamine as a neurotransmitter
• then acts at the opoid receptor sites in the brain, and changes the action of dopamine in the reward pathway of the brain, releasing more dopamine then usual
• the morphine binds to receptors to reduce the inhibitory effects of the neurotransmitter GABA on dopamine
• as a result, more dopamine activity and increased release of dopamine into the synaptic cleft, and if reward pathway continues being stimulated, can lead to feelings of euphoria

Question 5

What short term effects does heroin have on behaviour?

Answer 5

• feelings of pleasure
• reduction of pain
• a rush that includes a dry mouth, heavy limbs and slowing of mental functions, breathing and heart rate

Question 6

What long term effects does heroin have on neurotransmission?

Answer 6

• after a period of time, the same drug dose will not produce the same feeling of euphoria because the brain has adapted and now depends on the presence of the drug to function normally
• brain abnormalities persist causing feelings of discomfort and craving or more of the drug to relieve these feelings because they now produce less endorphins so rely on heroin for pleasure and reduction of pain

Question 7

How does the recreational drug amphetamine impact neurotransmission?

Answer 7

• it stimulates the central nervous system which speeds up the body’s processes such as breathing rate and heart rate
• it increases the concentration of dopamine in the synaptic gap. It is similar in structure to dopamine so can enter terminal buttons of the pre-synaptic gap.
• it reduces the re-uptake of dopamine causing additional binding of the dopamine to the receptors

Question 8

What short term effects does heroin have on behaviour?

Answer 8

• it increases heart rate and blood pressure
• decreases appetite
• dilated pupils
• feelings of happiness, power
• reduced fatigue

Question 9

What long term effects does amphetamine have on neurotransmission?

Answer 9

• insomnia
• restlessness
• psychosis
• hallucinations
• violent and aggressive behaviours
• weight loss
• tremors
• depression like symptoms due to serotonin dropping as neurotransmitters no longer stimulated
• over time dopamine receptors become damaged because of the over stimulation, leading to addiction as dopamine is required to stimulate neuron to a normal level