ABSTRACT
The region called the synapse is made up of the presynaptic terminal, the postsynaptic membrane region, and the small space between them known as the synaptic cleft. The synaptic cleft is an extremely small gap. The postsynaptic membrane contains specialized receptors to which the correct neurotransmitter substance can attach. Neurotransmitter substances are made in the cell body of the neuron but they are stored in the terminal bouton inside sacs called synaptic vesicles. These sacs are fixed to internal structures inside the bouton when the neuron is at rest. Once there, the vesicles fuse with the neuronal membrane to release the contents into the synaptic cleft. This process is called exocytosis. Once the neurotransmitter molecules are released into the synaptic cleft, they diffuse across the space and some land on receptors located in the postsynaptic membrane. The process of communication authors have been describing is designed to pass discrete messages between a neuron and the next cell.
