Brain Derived Neurotrophic Factor (BDNF) is a protein produced by your body that has the special function of growing and fixing neurons. BDNF is active primarily in the parts of your brain that mediate learning, complex thinking, and memory. Some research also shows that BDNF plays a vital role in the formation of long-term memories.
BDNF acts on a specific set of receptors in the brain to either grow new neurons or protect neurons that are being stressed, or have been damaged previously. Damage to your neurons can be perpetuated by daily offenses such as poor diet, lack of activity, lack of sleep, etc.
People suffering from diseases of the brain that are associated with aging, usually present with lower levels of BDNF. The role of BDNF in these various conditions is not completely understood, as science is just beginning to scratch the surface in understanding all of the different areas of brain health and function that BDNF affects.