refers to the process of making long-term changes in the brain.
Often these changes occur as a result of learning. During
development (the period of intense growth and change from
conception through early childhood), neurons
can change shape, location, function, and patterns interconnection.
In the adult brain, neurons are less able to change location
and function, but plasticity still occurs. For example, intensive
practice of a motor skill involving fine finger movements
(e.g. playing the guitar) may result in an increase in the
number of neurons that are devoted to motor control of the
fingers. Conversely, if a finger is lost, the neurons which
were originally devoted to processing sensory input from and
motor commands to that finger may reorganize and devote themselves
to an adjacent finger.
Less dramatic examples of plasticity also
occur as the biological basis of learning and memory. For
example, if two neurons are usually active at the same time,
then changes may occur to facilitate communication between
those two neurons in future. Long-term potentiation is one
way in which this kind of plasticity may occur. Long-term
potentiation refers to the fact that if two neurons are active
at the same time, the connection between them may be strengthened.
This change ("potentiation") can last for minutes to hours.
This may serve to lay a foundation for more permanent changes,
such as the construction of new connections (synapses) between
the neurons. Such structural alterations may provide a more
or less permanent change that could be the basis of long-term
Further reading: L. Squire and E. Kandel
(2000). Memory: From Mind to Molecules. New York: Scientific
by Catherine E. Myers. Copyright © 2006 Memory Loss and the Brain