There are chemical and structural phenomena that contribute to the development of synapses. Two examples of chemical and structural phenomena are the following:

-Growth cones are swellings at the tips of axons off which thin, threadlike fibers called filopodia extend. The filopodia of these growth cones can latch onto cellular adhesion molecules (CAMs) , and then contract move the neuron in the direction of the CAM (and, presumably, the location of the postsynaptic cell). Growth cones can also facilitate movement of dendrites, and thereby plasticity, in adults.

-Chemoattractants and chemorepellents are chemical signals that either attract or repel axonal growth cones, respectively. Gradients of these signaling molecules affect the distribution of neurons during the development of the nervous system.