In detail

The synapse - construction


Building the synapse

As Synapse (Greek syn = together, haptein = summarize) refers to the junction between two nerve cells or between nerve cell and another cell (for example, muscle cell). Synapses are essential for the neural function of any organism: neurons are transmission-specialized cells and the synapses provide for the transfer between cells.

A total of three areas are distinguished: the presynaptic membrane, the synaptic cleft and the postsynaptic membrane:
Presynaptic membraneEssentially, the presynaptic membrane consists of the synaptic terminal node, that is, the axon end of a nerve cell. It contains small vesicles filled with neurotransmitters (synaptic blisters). If an action potential reaches this point, the vesicles merge with the presynaptic membrane and empty the neurotransmitters into the synaptic cleft. In addition, Ca + channels and ion pumps are still located in the synaptic end-point.
Synaptic cleft: The synaptic cleft is the space between the presynaptic membrane of the axon end and the postsynaptic membrane of the next dendrites. The vesicles empty the neurotransmitters into the synaptic cleft, from where they diffuse to the receptors. Furthermore, there are numerous enzymes in the synaptic cleft responsible for the breakdown of neurotransmitters.
Postsynaptic membrane: The postsynaptic membrane belongs to the dendrites of a nerve cell. There are receptors in the membrane where the neurotransmitters can bind. If the neurotransmitters dock to the receptors, sodium channels open and cause an influx of positive Na + ions. The sodium channels remain open as long as transmitters bind to them