Models to study the role of neurotrophic factors in neurodegeneration

The physiological functions of neurotrophic factors, such as nerve growth factor (NGF), in supporting the survival and differentiation of specific neurons during early development has in many cases been well established. Recent studies have shown that neurotrophic factors can also protect vulnerable neurons against a variety of mechanical and chemical injuries. The role and the effects of neurotrophic factors in various neurological diseases are however less known. Neurodegenerative diseases such as Parkinson and Alzheimer's diseases as well as amyotrophic lateral sclerosis (ALS) are characterized by an impaired function and ultimate loss of specific populations of neurons. The study of the ethiology and molecular biology of these diseases has for a long time been hampered by the lack of good animal models mimicked part of the human disease in experimental animals. Here we will discuss some of the current approaches taken in these studies as well as address the important question of the possible beneficial effect of neurotrophic factors in alleviating the symptoms and possibly retarding the course of neurodegenerative diseases.