Long term potentiation in the hippocampus: mechanisms of initiation and modulation by neurotransmitters

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Abstract

Long term potentiation (LTP) of excitatory synaptic transmission in the hippocampus, induced by tetanic stimulation, is a widely used model of learning and memory. Graham Collingridge explains how recent studies have shown that N-methyl-d-aspartate (NMDA) receptors are responsible for the initiation of LTP. Mg2+, present extracellularly, may prevent expression of the NMDA system during normal synaptic transmission by blocking the associated ion channel. This block may be reduced during periods of repetitive activation so allowing transient expression of the NMDA system. By this mechanism NMDA receptors could play a unique role in the processing of information in the brain.

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