RECENT PROGRESS IN STUDIES OF NEUROTROPIC FACTORS AND THEIR CLINICAL IMPLICATIONS

Neurotrophic factors are endogenous soluble proteins that regulate lon g-term survival and differentia tion of neurons of the peripheral and central nervous systems. These factors play an important role in the s tructural integrity of the nervous system, and therefore are good cand idates as therapeutic agents for neurodegenerative diseases. However, recent studies have revealed some unexpected, novel roles of neurotrop hic factors, Of particular significance is the discovery of the new fu nctions of brain-derived neurotrophic factor (BDNF) and glia-derived n eurotrophic factor (GDNF), Physiological experiments indicate that BDN F may serve as regulatory factors for synaptic transmission as well as for learning and memory. Gene targeting studies demonstrate that GDNF may be essential for development of the enteric nervous system (ENS) and kidney organogenesis. These results not only provide new insights into our understanding of the function of neurotrophic factors but may also have significant implications in the therapeutic usages of neuro trophic factors.