with three trains of stimuli (1 sec at 100 Hz; 5 min between the trains). Short-term potentiation (STP) and LTP were evaluated at 1–15 min and 30–60 min after the tetanus respectively. Fluoxetine hydrochloride (Sigma-Aldrich, cat. # F-132) was dissolved in distilled water to a concentration of 2 mM, aliquoted, and stored at −30 °C. Fluoxetine was bath applied, at a final concentration of 10 μM, for 15 min before and 15 min after the tetanus.