Essential Idea:
Communication between neurons can be altered through the
manipulation of the release and reception of chemical messengers
Understandings:
- Some neurotransmitters excite nerve impulses in postsynaptic neurons and others inhibit them
- Nerve impulses are initiated or inhibited in postsynaptic neurons as a result of summation of all excitatory and inhibitory neurotransmitters received from presynaptic neurons
- Many different slow acting neurotransmitters modulate fast synaptic transmission in the brain
- Memory and learning involve changes in neurons caused by slow-acting neurotransmitters
- Psychoactive drugs affect the brain by either increasing or decreasing postsynaptic transmission
- Anaesthetics act by interfering with neural transmission between areas of sensory perception and the CNS
- Stimulant drugs mimic the stimulation provided by the sympathetic nervous system
- Addiction can be affected by genetic predisposition, social environment and dopamine secretion
Applications:
- Effects on the nervous system of two stimulants and two sedatives
- The effect of anaesthetics on awareness
- Endorphins can act as painkillers
Skill:
- Evaluation of data showing the impact of MDMA (ecstasy) on serotonin and dopamine metabolism in the brain