Final answer:
Presynaptic inhibition can be caused by the inactivation of Ca2+ channels, reduction in neurotransmitter release due to modulation by a second neuron, or the removal of SNARE complexes, all contributing to a decrease in signaling to the postsynaptic neuron. The answer is D) All of the choices are correct.
Step-by-step explanation:
What event(s) could cause presynaptic inhibition? The answer is D) All of the choices are correct. Presynaptic inhibition can indeed occur through multiple mechanisms such as:
- Inactivation of Ca2+ channels, which are essential for the vesicle release mechanism.
- A second neuron causing a reduction in neurotransmitter release from another neuron through modulatory effects.
- Removal of SNARE complexes, which are necessary for the fusion of neurotransmitter vesicles with the presynaptic membrane.
Each of these events can interfere with the normal process of neurotransmitter release at the synapse, leading to a decrease in signaling to the postsynaptic neuron.