Presynaptic cholinergic terminal

The presynaptic cholinergic terminal is the specialized region at the end of a cholinergic neuron’s axon responsible for the synthesis, storage, and regulated release of the neurotransmitter acetylcholine (ACh)[5][8][9]. Upon arrival of an action potential, voltage-dependent calcium channels trigger the fusion of synaptic vesicles with the plasma membrane, releasing ACh into the synaptic cleft, where it acts on postsynaptic and sometimes presynaptic acetylcholine receptors (both nicotinic and muscarinic types)[5][7]. Enzymatic breakdown of ACh by acetylcholinesterase in the synaptic cleft ensures the transient nature of cholinergic signaling[5][9]. Presynaptic cholinergic terminals play essential roles in neuromuscular junctions, autonomic ganglia, and widespread areas of the central nervous system, particularly in circuits critical for memory, attention, and arousal[7][9]. Loss or dysfunction of presynaptic cholinergic terminals is a hallmark of major neurodegenerative disorders, notably Alzheimer’s disease[7][9]. However, as an anatomical structure containing many molecular components (such as choline acetyltransferase, the vesicular ACh transporter, voltage-gated calcium channels, and others), it is not a molecular therapeutic target but instead the site where many therapeutic targets reside[5][8][9].

Other names

Cholinergic nerve terminalcholinergic axon terminalpresynaptic terminal of cholinergic neuron