The inhibition of MAO-A prevents metabolism of serotonin and catecholamines in the presynaptic terminal, and thus increases the amount of neurotransmitters available for release into the synaptic cleft.
Inhibition of MAO-A prevents the breakdown of serotonin and catecholamines within the presynaptic terminal, thereby enhancing the availability of these neurotransmitters for release into the synaptic cleft.