Circadian regulation and its disorders in Parkinson’s disease patients. Part 1: The role of dopamine in circadian dysfunction

Circadian disturbances related to Parkinson’s disease are reviewed, and possible pathogenetic mechanisms are discussed. The role of dopaminergic system degeneration in the development of circadian dysfunction is emphasized. The accumulation of α-synuclein in the suprachiasmatic nucleus is considered as a possible mechanism of circadian dysfunction unrelated to dopamine deficiency. Data on the disbalance of dopamine and melatonin levels in Parkinson’s disease patients and its role in disturbances of circadian rhythms of physiological processes are analyzed.