Developmental plasticity is a general term referring to changes in neural connections during development as a result of environmental interactions as well as neural changes induced by learning. Much like neuroplasticity or brain plasticity, developmental plasticity is specific to the change in neurons and synaptic connections as a consequence of developmental processes.
During development, the central nervous system acquires information via endogenous or exogenous factors as well as learning experiences. In acquiring and storing such information, the plastic nature of the central nervous system allows for the adaptation of existing neural connections in order to accommodate new information and experiences, resulting in developmental plasticity. This form of plasticity that occurs during development is the result of three predominant mechanisms: synaptic and homeostatic plasticity, and learning.
The underlying principle of synaptic plasticity is that synapses undergo an activity-dependent and selective strengthening or weakening so new information can be stored. Synaptic plasticity depends on numerous factors including the threshold of the presynaptic stimulus in addition to the relative concentrations of neurotransmitter molecules. Synaptic plasticity has long been implicated for its role in memory storage and is thought to play a key role in learning. However, during developmental periods synaptic plasticity is of particular importance as changes in the network of synaptic connections can ultimately lead to changes in developmental milestones. For instance, the initial overproduction of synapses during development is key to plasticity that occurs in the visual and auditory cortex. In experiments conducted by Hubel and Wiesel, the visual cortex of kittens exhibits synaptic plasticity in the refinement neural connections following visual inputs. Correspondingly, in the absence of such inputs during development, the visual field fails to develop properly and can lead to abnormal structures and behavior. Furthermore, research suggests that this initial overproduction of synapses during developmental periods provides the foundation by which many synaptic connections can be formed, thus resulting in more synaptic plasticity. In the same way that synapses are abundant during development, there are also refining mechanisms that coincidentally refine the connectivity of neural circuits. This regulatory process allows the strengthening of important or frequently used synaptic connections while reducing the amount of weak connections.