Option A5

Essential idea: Communication between neurons can be altered through the manipulation of the release and reception of chemical messengers.


A.5.U1 Some neurotransmitters excite nerve impulses in postsynaptic neurons and others inhibit them

Inhibitory and excitatory neurotransmitters

A.5.U2 Nerve impulses are initiated or inhibited in postsynaptic neurons as a result of summation of all excitatory and inhibitory neurotransmitters received from presynaptic neurons

Summation of inhibitory and excitatory neurotransmitters

A.5.U3 Many different slow-acting neurotransmitters modulate fast synaptic transmission in the brain

What is the mechanism of a slow-acting and fast-acting neurotransmitter

Difference between a slow-acting/fast-acting neurotransmitter

How does a slow-acting neurotransmitter modulate fast synaptic transmission?

Neuromodulation of presynptic and postsynaptic neurons

A.5.U4 Memory and learning involve changes in neurons caused by slow acting neurotransmitters

Changes in postsynaptic neuron involved in learning

A.5.U5 Psychoactive drugs affect the brain by either increasing or decreasing postsynaptic transmission

Effect of psychoactive drugs on postsynaptic transmission

A.5.U6 Anesthetics act by interfering with neurotransmission between areas of sensory perception in the CNS

Anesthetics block neurotransmission

A.5.U7 Stimulant drugs mimic the stimulation provided by the sympathetic nervous system

Effect of sympathetic nervous system and stimulants

A.5.U8 Addiction can be affected by genetic, predisposition, social environment and dopamine secretion

Addiction factors


A.5.A1 Effects on the nervous system of two stimulants and two sedatives

Stimulant 1: Cocaine effects dopamine reuptake channels

Cocaine works by blocking dopamine reuptake channels

Stimulant 2: Mdma effects dopamine and serotonin reuptake channels

Cocaine blocks both dopamine and serotonin reuptake channels

Depressant 1: Benzodiazepine effects GABA receptors

Benzodiazepine binds GABA allosteric receptors

Depressant 2: THC and the effects of G protein

THC and the effects of G proteins

A.5.A3 Endorphins can act as pain killers

Endorphins as painkillers

How do endorphins act as painkillers?

Endorphins as painkillers explained


A.5.S1 Evaluation of data showing the impact of MDMA (ecstasy) on serotonin and dopamine metabolism in the brain

What effect does mdma injections have on serotonin and dopamine levels?

Graph of serotonin and dopamine levels after mdma injections
Graph of serotonin and dopamine levels after mdma injections explained
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