Which of the following correctly lists the steps of synaptic transmission in the proper order?

• A. 1. Voltage-gated Ca^{2+} channels open → 2. Action potential arrives at axon terminal → 3. Synaptic vesicles release neurotransmitter → 4. Neurotransmitter binds to postsynaptic receptors
• B. 1. Action potential arrives at axon terminal → 2. Voltage-gated Ca^{2+} channels open → 3. Synaptic vesicles release neurotransmitter → 4. Neurotransmitter binds to postsynaptic receptors
• C. 1. Synaptic vesicles release neurotransmitter → 2. Action potential arrives at axon terminal → 3. Neurotransmitter binds to postsynaptic receptors → 4. Voltage-gated Ca^{2+} channels open
• D. 1. Neurotransmitter binds to postsynaptic receptors → 2. Action potential arrives at axon terminal → 3. Voltage-gated Ca^{2+} channels open → 4. Synaptic vesicles release neurotransmitter

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the process of synaptic transmission, which involves the transfer of a signal from one neuron to another across a synapse.
2. Step 2: Recognize that synaptic transmission begins when an action potential arrives at the axon terminal of the presynaptic neuron. This is the initial trigger for the sequence of events.
3. Step 3: Learn that the arrival of the action potential causes voltage-gated calcium (Ca^{2+}) channels in the axon terminal membrane to open, allowing Ca^{2+} ions to flow into the cell.
4. Step 4: Understand that the influx of Ca^{2+} ions prompts synaptic vesicles containing neurotransmitters to fuse with the presynaptic membrane, releasing the neurotransmitters into the synaptic cleft.
5. Step 5: Finally, the neurotransmitters diffuse across the synaptic cleft and bind to specific receptors on the postsynaptic neuron, initiating a response in the postsynaptic cell.