Encoding (memory) - Long-term Potentiation

Long-term Potentiation

Encoding is a biological event that begins with perception. All perceived and striking sensations travel to the brain’s hippocampus where all these sensations are combined into one single experience. The hippocampus is responsible for analyzing these inputs and ultimately deciding if they will be committed to long-term memory; these various threads of information are stored in various parts of the brain. However, the exact way in which these pieces are identified and recalled later remains unknown.

Encoding is achieved using a combination of chemicals and electricity. Neurotransmitters are released when an electrical pulse crosses the synapse which serves as a connection from nerve cells to other cells. The dendrites receive these impulses with their feathery extensions. A phenomenon called long-term potentiation allows a synapse to increase strength with increasing numbers of transmitted signals between the two neurons. For that to happen, NMDA receptor, which influences the flow of information between neurons by controlling the initiation of long-term potentiation in most hippocampal pathways, need to come to the play. For these NMDA receptors to be activated, there must be two conditions. Firstly, glutamate has to be released and bound to the NMDA receptor site on postsynaptic neurons. Secondly, excitation has to take place in postsynaptic neurons. These cells also organise themselves into groups specializing in different kinds of information processing. Thus, with new experiences the brain creates more connections and may ‘rewire’. The brain organizes and reorganizes itself in response to one's experiences, creating new memories prompted by experience, education, or training. Therefore the use of a brain reflects how it is organised. This ability to re-organize is especially important if ever a part of the brain becomes damaged. Scientists are unsure of whether the stimuli of what we do not recall are filtered out at the sensory phase or if they are filtered out after the brain examines their significance.