<P> Chemical synapses are biological junctions through which neurons' signals can be exchanged to each other and to non-neuronal cells such as those in muscles or glands . Chemical synapses allow neurons to form circuits within the central nervous system . They are crucial to the biological computations that underlie perception and thought . They allow the nervous system to connect to and control other systems of the body . </P> <P> At a chemical synapse, one neuron releases neurotransmitter molecules into a small space (the synaptic cleft) that is adjacent to another neuron . The neurotransmitters are kept within small sacs called synaptic vesicles, and are released into the synaptic cleft by exocytosis . These molecules then bind to neurotransmitter receptors on the postsynaptic cell's side of the synaptic cleft . Finally, the neurotransmitters must be cleared from the synapse through one of several potential mechanisms including enzymatic degradation or re-uptake by specific transporters either on the presynaptic cell or possibly by neuroglia to terminate the action of the transmitter . </P>

Where are chemical synapses found in the body