Consistently, a reduction of the number of OT-immunoreactive neurons in the hypothalamus of PD patients [97], and the ability of OT to influence locomotor activity at the level of the substantia nigra [98], possibly suggest that a decrease of OT levels in the brain areas receiving oxytocinergic projections may play a role in the motor disabilities in PD patients [98]. Here, OXT is linked to Parkinson disease.