When neurons interact with muscle fibers, the region of functional contact is called the neuromuscular junction or motor endplate (Chapter 4). According to the classical definition of synapse, when a nerve ending synapses on a dendrite or soma of a second neuron it is termed either an axodendritic or an axosomatic synapse, respectively (Chapter 7). However, almost all possible combinations of pre- and postsynaptic elements have been found in the central nervous system. These different types of synapse are designated by combining the name of the structure of the presynaptic element with that of the postsynaptic structure. For example, when the transfer of information occurs from an axon to axon or from one terminal to another, the synapse involved is called an axoaxonic synapse.