Specifically, it is also reported that stimulation of 5-HT1A receptors is effective for multiple PD symptoms including Parkinsonism, levodopa-induced dyskinesia (LID), cognitive impairment, mood disorders and neuro-degeneration of dopamine neurons (Ohno et al., 2015; Carta and Tronci, 2014). This evidence concerns the gene HTR1A and Parkinson disease.