Dopaminergic Transmitter Up-regulation of Brain-derived Neurotrophic Factor (BDNF) and Nerve Growth Factor (NGF) Synthesis in Mouse Astrocytes in Culture

We developed a highly sensitive enzyme immunoassay (EIA) system for brain-derived neurotrophic factor (BDNF) based on a biotin-streptavidin detection system capable of measuring concentrations as low as 1.0 pg/ml with high reproducibility. Using this EIA system, we examined the effect of dopaminergic transmitters such as dopamine and epinephrine on BDNF synthesis in mouse astrocytes in culture. These drugs had a stimulating effect on BDNF synthesis and showed a stronger promoting activity toward BDNF synthesis than toward nerve growth factor (NGF) synthesis. This is the first reported study in which BDNF synthesis was shown to be strongly stimulated by dopaminergic transmitter in mouse astrocytes. Then, we measured BDNF levels in the developing rat brain (striatum and midbrain). BDNF levels were relatively higher than NGF and NT-3 levels in these tissues. The BDNF level was high at the early stage in which neurons were proliferating, migrating, and differentiating, and it generally decreased as these cells matured.