text: In addition, by comparing the combined administration of (+/-)pindolol with either WAY100635, GR127935 or isamoltane, we have determined that << (+/-)pindolol >> produces much of its acute potentiation of fluoxetine-induced increases in extracellular 5-HT via its action at the 5-HT(1B/D) receptor in addition to any activity it has at the presynaptic [[ 5-HT(1A) ]] receptor.