Final answer:
Terminating neurotransmitter action involves reuptake, enzymatic degradation, and diffusion. Failure in these processes results in continuous postsynaptic stimulation, possibly leading to disorders or signal disruption.
Step-by-step explanation:
To terminate neurotransmitter action, three steps are needed: reuptake by the presynaptic neuron, enzymatic degradation, and diffusion away from the synaptic cleft. Reuptake involves the neurotransmitter being absorbed back into the neuron that released it. Enzymatic degradation, as seen with acetylcholine being broken down by acetylcholinesterase, inactivates neurotransmitters, and diffusion simply allows neurotransmitters to drift out of the synaptic cleft.
If these steps fail, the postsynaptic membrane could be constantly stimulated by neurotransmitters, making the neuron less likely to fire an action potential appropriately. This could result in continuous, unregulated signaling that can lead to disorders or signal disruption within neural circuits.