NTS and Parkinson disease: Our findings reveal the importance of ATP-dependent viscoadaptation in PD and ALS pathologies (Figs. 5 and 6 and table S1), as well as the rescue of normal axoplasmic viscosity and decondensation of pathological aggregates by chronic NMN treatment in PD and ALS neurons (Figs. 7 and 8 and table S1).