The IB say: The effect of neurotransmitters on human behaviour can be explained using an appropriate example. Neurotransmitters allow the impulse to cross a synapse (excitatory) or stop the impulse and prevent it from crossing a synapse (inhibitory). Neurotransmitters are themselves affected by agonists which amplify their effect and antagonists which reduce their effect. As a result, neurons working together can produce a large variety of effects resulting in a complex repertoire of behaviours. As a result any claim of cause and effect should be treated with caution.
From 2020 the following terms can be used in the formulation of SAQs.
- synapse (excitatory and inhibitory)
- agonists and antagonists
And when you just want to know a little bit more…
SAQs (Will always have command term outline, describe or explain)
- Explain how one neurotransmitter affects one behaviour. (9)
- Explain the excitatory and/or inhibitory effect(s) of one neurotransmitter on one human behaviour. (9)
- Explain how one agonist affects one behaviour. (9) Physostigmine improved LTM in humans – Davis1978 and Santucci et al. showed similar with rats
- Explain how one antagonist affects one behaviour. (9)
ERQs (Cannot use any of the ‘special’ terminology and will use commands terms evaluate, discuss, contrast and to what extent)
- Evaluate research into one or more neurotransmitters and their effects on behaviour. (22)
Links to Abnormal Option (Biological etiology of MDD)
Permissive Amine Hypothesis, (e.g. e.g. Moreno and Delgado and tryptophan)
Great Khan Academy videos to help you:
Drugs and the brain: Handy demo to learn about agonists and antagonists: https://opl.apa.org/src/index.html#/Demonstrations
A useful fact sheet about the use of Exelon, a cholinesterase inhibitor in the treatment of Alzheimer’s. Exelon is a derivative of physostigmine and interestingly the fact sheet suggests that this substance may be a direct agonist for acetylcholine as it appears to increases the sensitivity of the post-synaptic receptors as well as inhibiting the enzyme which breaks down acetylcholine.