HTR1A and drug-induced dyskinesia: For example (i) 5-HT1A receptor agonists reverse catalepsy induced by blockade of dopamine receptors with neuroleptics (McMillen et al., 1988; Wadenberg, 1996); (ii) (+)-8-OH-DPAT and sarizotan reduced L-DOPA-induced dyskinesia in monkeys with lesioned dopaminergic neurons in the substantia nigra (Iravani et al., 2006; Gregoire et al., 2009; Marin et al., 2009); and (iii) in clinical trials, sarizotan, buspirone, and tandospirone alleviated dyskinesia in PD patients (Bonifati et al., 1994; Kannari et al., 2002).