Therapeutic potential of nerve growth factors in Parkinson's disease

Parkinson's disease (PD) is a neurodegenerative syndrome which primarily af fects dopamine-producing neurons of the substantia nigra, resulting in pove rty and slowness of movement, instability of gait and posture, and tremor a t rest in individuals with the disease. While symptoms of the disease can b e effectively managed for several years with available drugs, the syndrome is progressive and the efficacy of standard drugs wanes with time. One expe rimental approach to therapy is to use natural and synthetic molecules whic h promote survival and growth of dopaminergic neurons, so-called 'neurotrop hic factors', to stabilise the diminishing population of dopaminergic neuro ns and stimulate compensation and growth in these cells. In this review, we examine the available evidence on 29 molecules with neurotrophic propertie s for dopaminergic neurons. The properties of these molecules provide ample reasons for optimism that a neurotrophic strategy can be developed that wo uld provide a significant treatment option for patients with PD. While the search continues for even more specific, potent aad long-lasting agents, th e single greatest challenge is the development of techniques for targeted d elivery of these molecules.