Cocaine withdrawal in Planaria

Cocaine-exposed planarians displayed abstinence-induced withdrawal behavior when placed into cocaine-free, but not cocaine-containing, water. The effect, manifested and quantified using a new spontaneous locomotor velocity metric, was dose-dependently related to cocaine exposure (8x10(-9) to 8x10(-5) M). Ultraviolet light (254 nm=7.83x10(-19) J), which was previously shown to interfere with drug-receptor interactions in Planaria, enhanced the abstinence-induced decreased locomotor velocity.