Release and reuptake. The time course of extracellular 5-HT is shown for a model experiment where the neuron was stimulated for 1/5 of a second (blue curve). In the presence of fluoxetine, the time course goes slightly higher and the decay time back to baseline doubles (green curve). We modeled the presence of fluoxetine by blocking half the SERTs. The curves are very similar to those in Figure six of .