Final answer:
Blocking calcium (Ca2+) from entering the axon terminal inhibits neurotransmitter release because calcium influx through voltage-gated channels is necessary for this process. Both ligand-gated and voltage-gated ion channels are integral to neuronal function for initiating and propagating electrical signals.
Step-by-step explanation:
Blocking the ion calcium (Ca2+) from entering the axon terminal would inhibit neurotransmitter release. Voltage-gated calcium channels are critical for the process as they open in response to the electrical change from the arriving action potential, allowing Ca2+ ions to enter the axon terminal. This influx of calcium triggers synaptic vesicles to release neurotransmitters into the synaptic cleft.
Ligand-gated and voltage-gated channels both play key roles in axon and axon terminal function. Ligand-gated channels open in response to the binding of neurotransmitters, allowing ions like Na+ and Cl− to flow across the membrane, resulting in changes in the postsynaptic potential. Voltage-gated channels, including sodium (Na+) and potassium (K+) channels, propagate the action potential along the axon and participate in resetting the membrane potential after an action potential has occurred.