Effects of Brain-Derived Neurotrophic Factor on Injured Dopaminergic Neurons

Publisher Summary This chapter discusses the effects of brain-derived neurotrophic factor (BDNF) on injured dopaminergic neurons. The degeneration of dopaminergic neurons of the substantia nigra is characteristic for Parkinson's disease and the loss of dopaminergic function is most likely responsible for the majority of behavioral deficits of the disease. The identification of a trophic factor able to promote survival and function of dopaminergic neurons and to protect them from degeneration after injury could have significant impact on the future treatment of Parkinson's disease. BDNF, a growth factor belonging to the neurotrophin protein family, which includes nerve growth factor (NGF), stimulates developmental growth and differentiation of dopaminergic neurons in culture. The pretreatment of cultured dopaminergic neurons with BDNF diminishes the susceptibility of these cells to intermediate concentrations of the selective dopaminergic neurotoxin MPP+. In contrast to these actions in vitro, it is found that intraventricular BDNF administration is unable to protect axotomized dopaminergic neurons from degeneration in a similar way as NGF offers protection for axotomized cholinergic neurons. However, these findings do not generally exclude that adult dopaminergic neurons are responsive to BDNF.