GLOSSARY

BDNF (brain-derived neurotrophic factor) is the most abundant neurotrophin in the brain; acting through the TrkB receptor, it promotes neuronal survival, synaptic growth, synaptic plasticity (LTP), learning, and memory, and is sometimes called “fertiliser for the brain”.

Sites of Production

• Brain: especially the hippocampus, cortex, and hypothalamus.
• Outside the brain: skeletal muscle (as a myokine), platelets (which store most blood BDNF), and the endothelium.

Functions

• Synaptic strengthening and memory consolidation.
• Neurogenesis and dendritic growth.
• Mood regulation: low BDNF is linked to depression, and some antidepressants raise its levels.
• Regulation of energy and appetite.

Genetics

The Val66Met polymorphism (in about 20–50 percent of people, depending on the population) reduces activity-dependent BDNF secretion and may affect