Rodent Model of ParkinsonâÂÂs Disease: Unilateral or Bilateral?

Parkinson’s disease (PD) is one of the most common neurodegenerative diseases affecting the aging population worldwide. Levodopa (L-DOPA) is the gold standard of PD therapy, which is administrated for symptomatic treatment. However, long-term application of L-DOPA leads to less effectiveness and a dose-dependent side effect of dyskinesia. Therefore, to help understand the pathogenesis and clarify potential therapeutic strategies, a great effort is made for the preclinical research on experimental PD models. Since the variety of the animal models is employed in the research work of PD, a controversy has arisen over the reproducibility of experimental models to clinical Parkinsonism. The experimental paradigms are diverse, with which partial Parkinsonism features can be induced in rodents, while others may be limited. Rodent models need to be validated for further use in pathophysiological and therapeutic investigations. This review summarizes the characteristics of the commonly used experimental PD models on rodents, including both unilateral and bilateral models, which may provide useful ideas on selection the most applicable animal model on specific aims of PD research. In conclusion, bilateral models are more consistent with the natural pathogenic process of PD, although there currently exists no model completely reproducing the clinical characteristics of human patients.