How does repeated activation of synapses affect reflex responses?

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Repeated activation of synapses can lead to changes in the strength of reflex responses, a phenomenon known as neuroplasticity. Depending on the nature of the stimulation, this can result in two distinct outcomes:

Habituation: When a stimulus is repeated many times, the postsynaptic potentials decrease in size, causing the behavioral response to weaken. This reduction occurs because fewer neurotransmitters are released, often due to the closing of calcium channels in the presynaptic terminals. In cases of long-term habituation, the number of active zones at nerve terminals may also be reduced.1
Sensitization: In this paradigm, the reflex activity increases in strength with added stimulation. This is driven by presynaptic facilitation, which involves an increase in the second messenger cAMP in the sensory neuron terminals. Long-term sensitization can lead to an increase in the number of active zones at the synapse.1