Long-Term Potentiation (LTP)
A persistent strengthening of synaptic connections following repeated stimulation, considered the cellular mechanism underlying learning and memory. LTP is dependent on BDNF and NMDA receptor activation. Enhancing LTP is a theoretical target for cognitive-enhancing peptide research.
Technical Context
LTP phases: early LTP (E-LTP, lasting 1-3 hours — requires protein kinase activation but not new protein synthesis; mechanisms: CaMKII-mediated AMPA receptor phosphorylation increasing single-channel conductance, and exocytosis of AMPA receptor-containing vesicles) and late LTP (L-LTP, lasting >3 hours to lifetime — requires new gene transcription and protein synthesis; mechanisms: PKA/CREB pathway activating transcription of plasticity-related genes, BDNF-TrkB signalling promoting dendritic spine growth and new synapse formation). LTP cooperativity (multiple inputs must be co-active), associativity (weak input paired with strong input can be potentiated — the cellular basis of associative learning), and input specificity (only activated synapses are strengthened) are key properties that map onto behavioural learning phenomena. LTP can be artificially induced by high-frequency electrical stimulation (tetanus) or by glutamate uncaging at single synapses. Enhancing LTP is a theoretical mechanism for cognitive-enhancing peptides.