I frequently hear expressions like "Dopamine flooding the brain" or "X neurotransmitter flooding the brain" used by people when talking to general audiences. For example: "Following [orgasm]? oxytocin floods the brain, causing feeling of deep connectedness between people"
What exactly is meant by "Oxytocin flooding the brain"? I'm interested in where and how it happens. Do they mean that excess neurotransmitters are released in the synaptic cleft? Is it localized to some brain areas, or is it indeed throughout the brain?
If they are indeed talking about the synaptic cleft, then I'm interested in how such "flood" triggers the change in state - the answer to this question suggests that the half life of dopamine is only about 2 seconds in prefrontal cortex. Assuming that the half life of oxytocin is similar, in the "oxytocin floods the brain and produces feeling of connectedness" example, does it mean that a single burst of oxytocin(x seconds in synaptic cleft) is enough to produce such feeling, or are they talking about sustained release or some kind of release loop mechanism?