presünapt

Presynaptic refers to the part of a synapse that is on the transmitting side of the neuronal junction. This includes the presynaptic terminal, which is typically the axon terminal of a neuron. It is within the presynaptic terminal that neurotransmitters are synthesized and stored in vesicles. Upon arrival of an action potential, these vesicles fuse with the presynaptic membrane, releasing their neurotransmitter contents into the synaptic cleft. The presynaptic neuron's electrical signal is thus converted into a chemical signal in the form of neurotransmitter release. This release is a critical step in synaptic transmission, allowing communication between neurons or between a neuron and an effector cell. The presynaptic terminal also contains mechanisms for reuptake or degradation of neurotransmitters after they have exerted their effect, helping to regulate the duration and intensity of the signal. The structure and function of the presynaptic component are essential for the proper functioning of the nervous system.