ADCYAP1 and Parkinson disease: More recently, we examined the basal ganglia of macaques and found that the PAC1R protein content is markedly reduced in an MPTP-induced parkinsonism-like state, which was partially reversed by benserazide/levodopa (B/L) treatment [14]; however, in this study we did not examine whether the PACAP mRNA (Adcyap1) was affected.