Parkinson's disease (PD) is a common neurodegenerative disorder caused by the progressive degeneration of the nigrostriatal dopaminergic pathway. The resulting loss of dopamine neurotransmission is responsible for the symptoms of the disease. Available treatments are initially successful in treating PD symptoms; however, their long-term use is associated with complications and they cannot stop the neurodegeneration. Current research aims at developing new therapies to
halt/reverse the neurodegenerative process, rather than treating
symptoms. Neurotrophic factors are proteins critical for maintenance and
protection of neurones in the developing and adult brain. Several
neurotrophic factors have been investigated for their protective effects
on dopaminergic neurones. Here we review some of the most promising
factors and provide an update on their status in clinical trials.