Pharmacological treatment with 3-iodo-tyrosine (3IY) (Sigma, St. Louise, MO) and alpha-methoxytryptophan ∝MTP (Sigma, St. Louis, MO) was carried out as described previously15. 10 mg/mL 3IY or 20 mM ∝MTP were dissolved in a heated aqueous 5% sucrose, 5% yeast solution. 2 mL of cooled drug solution was added to a Kimwipe in a training vial. 1 day old males were kept in these vials for 40–48 h at 25°C and 70% relative humidity prior to training.
