This hyperactivity participates in mechanical pain by promoting nociceptive transmission in the spinal cord at least involving 5-HT2AR and 5-HT3R. These results suggest that therapeutic approaches aiming at downregulating the activity of NRM 5-HT neurons or pharmacologically blockade of spinal 5-HT2AR and 5-HT3R would be pertinent in the treatment of pain in PD. The gene discussed is HTR3A; the disease is Parkinson disease.