Neural Tube Defect (NTD)

A birth defect caused by abnormal development of the neural tube, the structure which gives rise to the central nervous system. Neural tube defects include the absence of most/all of the brain (anencephaly) and a lack of protection of the spinal cord (spina bifida).

Neurodegenerative disease

A condition in which cells (neurons) of the brain and spinal cord are destroyed. Over time this leads to dysfunction in controlling movements, processing sensory information, and making decisions.


A chemical that is released from a nerve cell and results in the transmission of an impulse to another nerve cell or organ (e.g., a muscle). Acetylcholine, dopamine, and serotonin are neurotransmitters.

Nucleic acids

DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) are long polymers of “nucleotides” composed of a nitrogen-containing base (adenine, guanine, cytosine, uracil or thymine), a sugar (ribose or deoxyribose), and one or more phosphate groups.


A repeating unit of chromosomes that consists of DNA coiled around histones.