Go to Article >>

Plasticity 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 memory.

Further reading: L. Squire and E. Kandel (2000). Memory: From Mind to Molecules. New York: Scientific American Library.