Brain-Derived Neurotrophic Factor (BDNF) is a member of the neurotrophin family. Along with other structurally related neurotrophic factors NGF, NT-3 and NT-4, BDNF binds with high affinity to the TrkB kinase receptor. It also binds with the LNGFR (for low-affinity nerve growth factor receptor, also known as p75). BDNF promotes the survival, growth and differentiation of neurons. It serves as a major regulator of synaptic transmission and plasticity at adult synapses in many regions of the CNS. BDNF expression is altered in neurodegenerative disorders such as Parkinson's and Alzheimer's disease.