Final answer:
When neurotransmitters bind to receptors at the axon terminal, they typically cause ion channels to open, leading to depolarization of the receiving end of an interneuron. The correct answer to the student's question is option 1.
Step-by-step explanation:
At the axon terminal, each action potential leads to the release of neurotransmitter molecules. These molecules then diffuse across the synaptic cleft and bind to receptors on the postsynaptic neuron.
When neurotransmitters bind to these receptors, it typically results in ion channels opening, through which ions can enter or leave the neuron. This process can cause a change in the electric potential of the receiving end of an interneuron, commonly resulting in depolarization.
The most accurate description of what happens when neurotransmitter binds to receptors and causes ion channels to open on the receiving end of an interneuron is option 1) ion channels to open, so that the receiving end of the interneuron depolarizes. This is because binding of the neurotransmitter to its receptor commonly causes a change in the balance of ions across the neuron's membrane, which alters its membrane potential and can lead to a new action potential if the change is sufficient.