- Autophagy
- The cell’s recycling process for damaged proteins and organelles. Its decline with age is one of the twelve hallmarks of aging; the removal of damaged mitochondria specifically is called mitophagy.
- Alpha-synuclein
- A protein abundant in neurons that misfolds and clumps into Lewy bodies in Parkinson’s disease and related conditions.
- Amyloid beta (Aβ)
- A peptide that accumulates into plaques between neurons in Alzheimer’s disease. One of the first waste products shown to travel the glymphatic route.
- Aquaporin-4 (AQP4)
- A water channel concentrated on astrocyte endfeet around blood vessels. Removing it in mice slows CSF influx and cuts solute clearance by roughly 70 percent.
- Astrocyte
- A star-shaped support cell of the brain. Astrocyte endfeet form the outer wall of perivascular spaces and regulate water movement.
- Blood–brain barrier (BBB)
- The tightly sealed lining of brain blood vessels that controls what passes from blood into brain tissue. It protects the brain but also blocks most drugs; focused ultrasound can open it briefly.
- Cerebral blood flow (CBF)
- The volume of blood passing through the brain per unit time. Tightly regulated to match the brain’s demand, and influenced by blood pressure, neural activity and blood chemistry.
- Cerebrospinal fluid (CSF)
- The clear fluid produced in the brain’s ventricles that surrounds and flows through the brain and spinal cord, cushioning them and carrying nutrients and waste.
- GFAP
- Glial fibrillary acidic protein, a structural protein in astrocytes. Its level in blood is used as a marker of astrocyte activity or injury.
- Glymphatic system
- The brain-wide pathway, described in 2012, by which CSF flows into brain tissue along arteries, exchanges with interstitial fluid and leaves along veins, clearing waste. Named for its dependence on glial cells and its lymphatic-like function.
- Interstitial fluid (ISF)
- The fluid in the narrow spaces between brain cells.
- Meningeal lymphatics
- Lymphatic vessels in the membranes surrounding the brain, rediscovered in 2015, that drain CSF and interstitial fluid toward the lymph nodes of the neck.
- Mitochondria
- The structures inside cells that convert nutrients into usable energy. Neurons depend on them heavily, and mitochondrial dysfunction is a recognised hallmark of aging and a feature of Parkinson’s and Alzheimer’s disease.
- Microglia
- The brain’s resident immune cells, responsible for surveillance, debris clearance and pruning of connections.
- Neurofilament light (NfL)
- A structural protein of neurons. Its level in blood or CSF rises when neurons are injured and is used as a general marker of neuronal damage.
- Non-REM sleep
- The stages of sleep without rapid eye movements, including deep slow-wave sleep, when CSF pulsation and clearance are strongest.
- Neuroplasticity
- The brain’s ability to change its structure and connections in response to experience, learning, injury or training, at any age.
- p-tau217
- A form of the tau protein, phosphorylated at position 217, whose level in blood tracks Alzheimer’s pathology closely. The basis of the first FDA-cleared blood test for Alzheimer’s in 2025.
- Perivascular space
- The thin, fluid-filled sleeve surrounding blood vessels as they enter the brain; the highway of the glymphatic system.
- SANS
- Spaceflight-associated neuro-ocular syndrome: changes to the eye and optic nerve seen in astronauts after long missions, linked to headward fluid shift.
- Senescent cell
- A cell that has permanently stopped dividing but remains metabolically active, releasing inflammatory signals. Senescent cells accumulate with age.
- Tau
- A protein that stabilises the internal skeleton of neurons. In Alzheimer’s disease it becomes abnormally modified and forms tangles inside cells.
- Vasomotion
- Slow, rhythmic constriction and dilation of blood-vessel walls, independent of the heartbeat. One of the forces that moves fluid through the glymphatic system.
How to read this page
This is general educational background drawn from the sources below. It is not medical advice, and it is not evidence that any NeuroClearance system works. Where a finding comes from animals or from a small human study, the text says so.