HD Glossary

Note: Some words can have differing definitions depending on the context in which they are used. The definitions presented here are the ones that best apply to the words as they are used. HDSA is grateful to the Stanford Hopes website for their contribution and maintenance of this glossary.



  • validation [To validate a protein as a biological target it must be proven that the potential target is relevant to the disease and that it is drugable - that is, can it be targeted and that its function can be changed by treatment with a drug
  • vascular - Pertaining to or made up of blood vessels.
  • vasodilation - The stretching and shrinking of blood vessels as blood is pumped by the heart.
  • vector - A method for delivering gene therapy. Modified viruses are common vectors for transmitting genetic material.
  • ventral horn - Another term for anterior horn.
  • ventricles - Openings in the brain that are common to all humans. In people with HD, the ventricles may become enlarged due to the decay of neurons in the surrounding area. A picture of some enlarged ventricles can be seen in Figure D-2 (the ventricles are called "openings" in this figure)
  • vertebrate - An animal whose nerve cord is surrounded by a backbone. The main groups of vertebrate animals are the fishes, amphibians, reptiles, birds, and mammals.
  • vesicles - Vesicles are created when part of the cell membrane pinches off and surrounds some kind of cellular product in an enclosed compartment. Vesicles store, transport, or digest cellular products and wastes.
  • virus - An intracellular parasite that depends on the host cell machinery to manufacture copies of itself. Viruses are not living organisms.
  • visual cortex - The part of the cerebral cortex that processes visual information. The visual cortex is where we actually see the images before our eyes.
  • vitamin A - A lipid-soluble vitamin with antioxidant properties that may also play an important role in learning and memory.
  • vitamin B3 - Another term for nicotinamide.
  • vitamin B11 - Another name for folic acid.
  • vitamin C - A vitamin with antioxidant properties that may help protect nerve cells from free radical damage and glutamate toxicity. Also known as ascorbic acid.
  • vitamin D - A hormone, synthesized from cholesterol, which promotes the uptake of calcium.
  • vitamin E - A lipid-soluble antioxidant that protects cell membranes and other lipid cell components from free radical damage.
  • voltage - A force caused by a difference in electric charge between two areas.