What is Long-term potentiation?
Long-term potentiation (LTP) is a persistent strengthening of synaptic connections following specific patterns of neural activity. It is the primary cellular mechanism underlying learning and memory formation.
How it works
LTP was discovered by Terje Lomo in 1966 in the hippocampus. When a synapse is repeatedly activated with high-frequency stimulation, the postsynaptic response becomes larger and remains enhanced for hours, days, or longer. The molecular mechanism involves NMDA receptor activation, calcium influx, and insertion of additional AMPA receptors into the postsynaptic membrane. Hebb’s rule captures the principle: ‘Neurons that fire together wire together.’ LTP satisfies the criteria for a memory mechanism: it is input-specific, associative, and long-lasting.
Applied example
When a person studies a new vocabulary word by repeatedly pairing the word with its meaning, the synapses connecting the neural representations of the word and its definition undergo LTP, becoming stronger with each repetition until the association is maintained long-term.
Why it matters
Long-term potentiation is the physical basis of learning at the cellular level, explaining how experience permanently changes the brain’s wiring and providing the mechanism through which behavior change literally reshapes neural circuits.
