Neural Cells, Electrophysiology and Synapses
Neuronal and glial organisation, membrane potentials, ion channels, action potentials, synaptic transmission, plasticity and pruning.
How to prepare for MRCPsych Paper A
Build mechanisms first, connect them to development and assessment, then practise distinguishing one best answer within SBA and extended-matching formats.
Core concepts
Concept 1
Neurons and glia are organised by region and layer; membrane gradients, ion channels and receptor-linked conductance produce resting potentials and action potentials.
Exam cue: Trace electrical signalling from membrane gradient to threshold, spike propagation, transmitter release and postsynaptic effect.
Concept 2
Synaptic strength changes through presynaptic and postsynaptic mechanisms, while plasticity and pruning support learning, development and adaptation.
Exam cue: Separate a fast ionotropic effect from a slower metabotropic or gene-expression effect.
Risk pitfalls and guardrails
Describing glia only as passive support cells.
Guardrail: Do not select an option because it is merely associated or familiar; choose the one that answers the exact lead-in.
Assuming every synaptic change is excitatory or permanent.
Guardrail: Do not select an option because it is merely associated or familiar; choose the one that answers the exact lead-in.
Memory anchors
What maintains the resting membrane potential?
Selective membrane permeability and ion gradients maintained by transporters, especially the sodium–potassium pump.
What initiates an action potential?
Membrane depolarisation reaching threshold opens voltage-gated channels and triggers regenerative depolarisation.
How do ionotropic and metabotropic receptors differ?
Ionotropic receptors directly gate ion channels; metabotropic receptors act through G proteins and intracellular signalling.
What is synaptic plasticity?
Activity-dependent change in the strength or structure of synaptic transmission.
Why is pruning important?
Selective elimination and refinement of connections helps developing networks become efficient and specialised.
Checkpoint rule
Do the check-up only after you can summarize each concept in one sentence and identify one dangerous pitfall from memory.
Knowledge Check (after reading)
Short check-up to confirm understanding of this module.
Check-up Questions
Which glial cell forms myelin in the central nervous system?
Which cell forms myelin around peripheral nerves?
Answer all questions to submit.
Next step personalized recommendations
Continue learning
Move forward only after this module is stable.
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