What is the result of calcium ions (Ca++) entering a neuron during neurotransmitter release?

What is the result of calcium ions (Ca++) entering a neuron during neurotransmitter release?

• A. Inhibition of neurotransmitter synthesis
• B. Promotion of neuroinflammation
• C. Triggering exocytosis of neurotransmitter vesicles
• D. Alteration of the membrane potential

Answer: (C)

The entry of calcium ions (Ca++) into a neuron plays a pivotal role in the process of neurotransmitter release. When an action potential reaches the terminal of a neuron, voltage-gated calcium channels open, allowing Ca++ to flow into the neuron. The increase in intracellular calcium concentration is a critical signal that triggers the exocytosis of neurotransmitter vesicles. During exocytosis, synaptic vesicles that contain neurotransmitters fuse with the presynaptic membrane. This fusion is facilitated by various proteins, including synaptotagmin, which binds calcium ions and induces a conformational change that leads to the fusion of the vesicle membrane with the plasma membrane. As a result, neurotransmitters are released into the synaptic cleft, where they can then bind to receptors on the postsynaptic neuron, continuing the signal transmission. In this context, the other options do not relate directly to the immediate effects of calcium ion influx during neurotransmitter release. The process emphasizes the critical role of Ca++ in initiating the cascade that leads to the release of neurotransmitters, thereby facilitating communication between neurons.

The entry of calcium ions (Ca++) into a neuron plays a pivotal role in the process of neurotransmitter release. When an action potential reaches the terminal of a neuron, voltage-gated calcium channels open, allowing Ca++ to flow into the neuron. The increase in intracellular calcium concentration is a critical signal that triggers the exocytosis of neurotransmitter vesicles.

During exocytosis, synaptic vesicles that contain neurotransmitters fuse with the presynaptic membrane. This fusion is facilitated by various proteins, including synaptotagmin, which binds calcium ions and induces a conformational change that leads to the fusion of the vesicle membrane with the plasma membrane. As a result, neurotransmitters are released into the synaptic cleft, where they can then bind to receptors on the postsynaptic neuron, continuing the signal transmission.

In this context, the other options do not relate directly to the immediate effects of calcium ion influx during neurotransmitter release. The process emphasizes the critical role of Ca++ in initiating the cascade that leads to the release of neurotransmitters, thereby facilitating communication between neurons.