presynaptic dense projection

Presynaptic dense projections are specialized areas on the presynaptic membrane of a neuron's axon terminal. These thickened regions are associated with synaptic vesicles, which contain neurotransmitters. When a nerve impulse arrives at the presynaptic terminal, these vesicles move toward the membrane, fuse with it, and release neurotransmitters into the synaptic cleft. This process is crucial for transmitting signals between neurons or from a neuron to a muscle or gland cell. The presynaptic dense projections play a role in regulating the docking and release of these neurotransmitter-filled vesicles, ensuring efficient synaptic transmission.12