ABSTRACT
Parkinson’s disease (PD), the second most common age-related progressive neurodegenerative disorder, is characterized by the loss of dopaminergic (DA) neurons, intracellular inclusions of aggregated proteins and neuroinfl ammation (Bjorklund, 2005). The most prominent symptoms of PD are tremor, rigidity, bradykinesia, and postural instability (Arenas, 2010). As symptoms progresses, patients will develop diffi culties in walking, talking, or completing simple tasks. Moreover, later symptoms could include psychiatric, autonomic and cognitive disorders (Beck, 1995; Weisman and McKeith, 2007). The pathologic hallmark of PD is primarily the progressive degeneration of dopaminergic neurons in the substantia nigra pars compacta of the ventral midbrain, resulting in a dopamine defi ciency in the nigrostriatal pathway (Arias-Carrion et al., 2007). Currently there is no cure or effective treatment for PD and numerous approaches to slow the neuronal loss or stop the disease progression have failed (Yokochi, 2009). Dopamine agonists, levodopa, enzyme inhibitors, and deep brain stimulation are being routinely used for treating PD patients, but their effi cacy is very limited (Lindvall and Kokaia, 2010).
