Impact of Spaceflight on Brain Fluid Dynamics

• 19 Jun 2023

Why in News?

Recently, a study was published in Scientific Reports, which sheds light on the effects of Spaceflight on the Brain, particularly concerning Longer Missions and the recovery period between flights.

• The study involved MRI (Magnetic Resonance Imaging) scans of 30 astronauts before and after spaceflight. These participants encompassed various mission durations, including two-week missions, six-month missions, and longer expeditions.

What are the Key Highlights of the Study?

• Spaceflight-Induced Brain Changes:
  • The extended stays in space lead to fluid changes in the brain, with ventricles—cavities filled with cerebrospinal fluid—expanding progressively.
    • Cerebrospinal fluid is a clear, colorless fluid that surrounds and protects the brain and spinal cord. It is produced in the ventricles of the brain and circulates throughout the central nervous system.
• Recovery Time between Missions:
  • Astronauts who had over three years of recovery time experienced an increase in ventricular volume after their most recent mission.
  • Conversely, those with shorter recovery periods demonstrated minimal to no ventricular enlargement after spaceflight.
• Association between Inter-Mission Delay and Brain Changes:
  • Longer inter-mission delays were linked to greater increases in left and right lateral and third ventricle volumes following spaceflight.
  • However, the fourth ventricle exhibited the opposite pattern, with longer inter-mission intervals correlating with greater volumetric decreases after space travel.

What is the Significance of the Study?

• Understanding the influence of both previous and current spaceflight experiences on brain changes is crucial for safeguarding astronauts' health.
• There is a need to consider adequate recovery periods between missions, exceeding three years, to enable the brain's compensatory mechanisms to normalize intracranial fluid levels.
• By addressing these factors, future space missions can better protect astronauts from potential long-term neurological implications and enhance their overall well-being.

What are Brain Ventricles?

• About:
  • Brain ventricles are cavities within the brain that produce and store Cerebrospinal Fluid (CSF), which surrounds the brain and spinal cord, cushioning them and protecting them from trauma.
  • They are also responsible for removing waste and delivering nutrients to your brain.
  • There are Four Brain Ventricles:
    • The first and second ventricles are lateral ventricles. These C-shaped structures are located on each side of the cerebral cortex, the wrinkly outer layer of Brain.
    • The third ventricle is a narrow, funnel-shaped structure situated between the right and left thalamus, just above your brain stem.
    • The fourth ventricle is a diamond-shaped structure that runs alongside the brain stem.
      • It has four openings through which cerebrospinal fluid drains into an area surrounding the brain (subarachnoid space) and the central canal of the spinal cord.

• Functions:
  • CSF Circulation: The ventricles, specifically the lateral ventricles, are interconnected with the third ventricle in the midline of the brain. CSF flows through these ventricles and circulates around the brain and spinal cord, helping to remove waste products and regulate the extracellular environment.
  • Maintenance of Intracranial Pressure: The ventricles help maintain the appropriate pressure within the brain. Any disruption in the production, circulation, or absorption of CSF can lead to an imbalance in intracranial pressure, which may result in conditions like hydrocephalus.

Source: TH