Final answer:
Ca²+ ions are most directly responsible for exocytosis of synaptic vesicles. Ca²⁺ ions are the key players in mediating the exocytosis of synaptic vesicles, which occurs when voltage-gated Ca²⁺ channels open due to an action potential reaching the axon terminals, leading to neurotransmitter release.
Step-by-step explanation:
The most directly responsible for exocytosis of synaptic vesicles is Ca²+ ions. When Ca²+ ions enter the presynaptic membrane, they cause synaptic vesicles to fuse with the membrane and release neurotransmitter molecules into the synaptic cleft through exocytosis.
Ca²⁺ ions are the key players in mediating the exocytosis of synaptic vesicles, which occurs when voltage-gated Ca²⁺ channels open due to an action potential reaching the axon terminals, leading to neurotransmitter release.
The Ca²⁺ ions are most directly responsible for the exocytosis of synaptic vesicles. When an action potential reaches the axon terminals, voltage-gated Ca²⁺ channels open, allowing an influx of Ca²⁺ into the synaptic end bulb. This increase in Ca²⁺ concentration inside the end bulb causes the Ca²⁺ ions to interact with proteins on the outer surface of neurotransmitter vesicles, facilitating their fusion with the presynaptic membrane. Consequently, neurotransmitters are released into the synaptic cleft through exocytosis. The most directly responsible for exocytosis of synaptic vesicles is Ca²+ ions. When Ca²+ ions enter the presynaptic membrane, they cause synaptic vesicles to fuse with the membrane and release neurotransmitter molecules into the synaptic cleft through exocytosis. Ca²⁺ ions are the key players in mediating the exocytosis of synaptic vesicles, which occurs when voltage-gated Ca²⁺ channels open due to an action potential reaching the axon terminals, leading to neurotransmitter release.