1-Does 4-FA increase or decrease synaptic cleft serotonin?

This article seems to say it decreases serotonin http://www.sciencedirect.com/science/article/pii/0028390875900994 "...reduced the activity of tryptophan hydroxylase and lowered the levels of serotonin and 5-hydroxyindoleacetic acid in whole brain initially." and "...lowered serotonin and 5-hydroxyindoleacetic acid levels only for short times (2–6 hr) after drug injection."

Most descriptors of this chemical say its boosts serotonin and that's why it has its entactogenic effects.

2-Also, does the serotonin get broken down more than it normally would since its sitting in the synaptic cleft longer?

3-Similarly, is the lowered response to 4-FA with a second use shortly after an initial use due to serotonin receptor down-regulation AND less of the serotonin being available in the cell?