The extracellular DA metabolite 3-Methoxytyramine hydrochloride (3-MT) induces significant behavioral activation in DDD mice. This activity however, is mostly presented as a set of disorganized abnormal movements that includes tremor, head bobbing, straub tail, grooming and abnormal orofacial movements rather than normal forward activity. No effect is observed when 3-Methoxytyramine hydrochloride is infused at doses below 9 µg, at 9 µg and higher doses 3-Methoxytyramine hydrochloride dose-dependently causes transient behavioral activation with a complex set of behaviors. In particular, transient hyperactivity and stereotypy, sniffing, grooming, rearing and mild abnormal involuntary movements (AIMs) at the level of limbs is observed after infusion of 9 µg of 3-Methoxytyramine hydrochloride. Similar behaviors are also observed after 18 µg of 3-Methoxytyramine hydrochloride with the additional appearance of tremor as well as oral and whole body AIMs.