The control exerted by 5-HT1B receptors at the terminals might not be fully functional by itself because the stimulation of these receptors alone does not reduce L-DOPA-stimulated striatal DA release (Kannari et al., 2001) but ameliorates dyskinesia when co-administered together with 5-HT1A agonists (Muñoz et al., 2009). Here, HTR1A is linked to drug-induced dyskinesia.