Brain: Embryology
The brain is encased in the skull and surrounded by three meningeal layers (dura mater, arachnoid, pia mater) and cerebrospinal fluid (CSF). The cerebrum (left and right hemispheres) handles higher cognition. The cerebellum coordinates movement. The brainstem controls vital autonomic functions.
Normal Function
Embryology perspective: Central processing of all sensory inputs, coordination of motor outputs, consciousness, cognition, memory, emotion, and autonomic regulation. Composed of approximately 86 billion neurons with trillions of synaptic connections.
Lunar Adaptations
On Arrival (First Weeks)
Cephalad fluid shift increases CSF volume in the cranial compartment, potentially raising intracranial pressure. Cognitive effects of the novel environment: heightened alertness initially, followed by adaptation. Sensory deprivation from altered environment (no wind, no outdoor sounds, artificial lighting) begins to affect perception.
6-Month Resident
Some residents show detectable structural brain changes on MRI: pituitary flattening, optic nerve sheath dilation (from ICP elevation), narrowing of the central sulcus (brain swelling). Cognitive performance on standardized tests shows mild changes in spatial processing tasks, likely from vestibular re-referencing.
Long-Term Resident (2+ Years)
Long-term structural changes documented: ventricular volume changes, white matter changes in certain tracts. Individual variability is large. Cognitive adaptations appear: lunar residents perform better on tasks relevant to lunar environment while losing some Earth-environment cognitive automaticity. Radiation effects on brain: increased risk of white matter lesions and potentially accelerated cognitive aging with cumulative doses.