Nerve growth factor in brain diseases

The nerve growth factor (NGF) belongs to a family of proteins termed neurotrophins, consisting of NGF, brain-derived neuro- trophic factor (BDNF), neurotrophin-3 (NT-3), NT-4/5 and NT-6. Today, NGF is well recognized to mediate a large number of trophobiological actions resulting in neurotrophic, immunotrophic and/or metabotrophic effects. The pathobiology of neurode- generative diseases, including Alzheimer disease, psychiatric disorders (e.g. depression and schizophrenia) and brain parasitic infection have in common the effect of altering the brain levels of neurotrophins and in particular NGF. The involvement of NGF and its TrkA receptor in these pathologies and the recent promising results of NGF therapies are presented and discussed.