It is a neural mechanism that plays a role in encoding of new information. Encoding takes place as a result of changes in the strength of synapses among neurons in neuronal networks that process and store information. This change occurs when one or more axons connected to some dendrite bombard it with a brief but rapid series of stimuli-such as 100 synaptic excitations per second for 1to 4 seconds. The burst of intense stimulation leaves the synapses potentiated (more responsive to new input of the same type) for minutes, days or weeks. This phenomenon is termed as long term potentiation. It occurs in many brain areas and is particularly prominent in hippocampus.
The chemicals involved in LTP are glutamate and its receptors - NMDA and AMPA. A wide variety of drugs that interfere with LTP also blocks encoding process whereas drugs that facilitate LTP enhance the process.