Related Experiment Videos
Scanning electron microscopy and electron probe microanalysis studies of human pineal concretions
1Department of Oral Anatomy, School of Dentistry, Showa University, Tokyo, Japan.
Journal of Electron Microscopy
|October 1, 1994
Summary
Human pineal gland concretions, or brain sand, form through calcification of pinealocytes. These structures, primarily calcium and phosphate, exhibit hydroxyapatite crystal composition.
Area of Science:
- Mineralogy
- Human Anatomy
- Biomineralization
Background:
- Human pineal bodies contain calcareous concretions, commonly known as brain sand.
- The formation and composition of these concretions are not fully understood.
Purpose of the Study:
- To investigate the morphological development and elemental composition of human pineal concretions.
- To elucidate the calcification and crystallization processes within these structures.
Main Methods:
- Scanning electron microscopy (SEM) for morphological analysis.
- Electron probe microanalysis (EPMA) for elemental composition determination.
Main Results:
- Concretions originate from calcified pinealocytes, growing appositionally with concentric laminations.
- Morphological variations include simple calcospherulites, aggregated spherulites, and lobated structures.
- Major elements are Calcium (Ca) and Phosphorus (P); traces of Sulfur (S), Magnesium (Mg), and Sodium (Na) were detected.
- Higher calcification and crystallization values were observed in the center of larger concretions (>50 microns).
- Elemental analysis suggests sand-grain-shaped crystals are nearly hydroxyapatite (Ca/P molar ratio ~1.68).
Conclusions:
- Pineal concretions exhibit a complex developmental pathway involving cellular calcification and aggregation.
- The elemental composition and crystalline structure indicate a hydroxyapatite-like mineral phase.
- Further research may clarify the physiological role of these biogenic minerals.