Fig. 7
From: The onset of motor learning impairments in Parkinson’s disease: a computational investigation
Schematic representation of the pathogenesis of PD in patients and animal models. A The manifestation of progressive degradation of the nigrostriatal DAergic system in patients with PD as a loss of DA in the striatum to a threshold level of dopamine, which is associated with the onset of motor disorders. B Progressive loss of DAergic neurons in the substantia nigra when modeling preclinical and clinical stages of PD in mice by subcutaneous injections. Reproduced from Ugrumov [40, Fig. 1A,D]