HTR2A and Parkinson disease: The specific proposal is that psychedelic 5-HT2A agonists act through the 5-HT2AR/mGlu2R heterocomplex and activate Gi/o-dependent signalling as well as Gq/11.30,31 We reasoned that by targeting the Gi/o-dependent pathway (through SRC-kinase inhibition) we could reduce the psychedelic effects of psilocybin in healthy volunteers, conferring the potential to reduce VH in Parkinson's disease (PD).