Brain-derived neurotrophic factor (BDNF) is a protein that plays a crucial role in the growth, maintenance, and survival of neurons in the brain. It supports the development of new neurons and synapses, which are essential for learning, memory, and overall brain health. BDNF is often referred to as a "neurotrophin" because it helps nourish and protect nerve cells. Research has shown that levels of BDNF can be influenced by various factors, including physical exercise, diet, and mental stimulation. Low levels of BDNF have been associated with several neurological disorders, such as Alzheimer's disease and depression, highlighting its importance in maintaining cognitive function and emotional well-being.