Final answer:
When calcium channels in the presynaptic membrane remain open longer, the release of neurotransmitters increases as more calcium ions trigger the fusion of synaptic vesicles with the membrane, enhancing the signaling process.
Step-by-step explanation:
When calcium channels in the presynaptic membrane remain open longer, there is an increased influx of Ca2+ ions into the presynaptic neuron. This causes more of the membrane-bound synaptic vesicles, which contain neurotransmitters, to fuse with the presynaptic membrane and release their contents into the synaptic cleft. Consequently, the release of neurotransmitters increases, facilitating a stronger signal to the postsynaptic neuron.
Neurotransmitter release is crucial for the communication between neurons. The entry of calcium through voltage-gated Ca2+ channels triggers synaptic vesicles to merge with the membrane, leading to the exocytosis of neurotransmitters into the synaptic cleft. This is a key step in synaptic transmission.