A randomized clinical trial of high-dosage coenzyme Q10 in early Parkinson disease: no evidence of benefit.

Importance: Coenzyme Q10 (CoQ10), an antioxidant that supports mitochondrial function, has been shown in preclinical Parkinson disease (PD) models to reduce the loss of dopamine neurons, and was safe and well tolerated in early-phase human studies. A previous phase II study suggested possible clinical benefit.

Objective: To examine whether CoQ10 could slow disease progression in early PD.

Respiratory response to activation or disinhibition of the dorsal periaqueductal gray in rats.

The neural substrates mediating autonomic components of the behavioral defense response have been shown to reside in the periaqueductal gray (PAG). The cardiovascular components of the behavioral defense response have been well described and are tonically suppressed by GABAergic input. The ventilatory response associated with disinhibition of the dorsal PAG (dPAG) neurons is unknown.