Related Experiment Videos
Fatty acid composition of human brain phospholipids during normal development
1Center for Research in Biochemistry and Molecular Biology, Maternity-Children's Hospital Vall d'Hebron, Barcelona, Spain.
Insights
Human brain development shows significant changes in fatty acid composition of key lipids like PE and PC, with docosahexaenoic acid increasing with age. Sphingomyelin composition also dramatically changes postnatally, highlighting lipid dynamics during brain maturation.
Area of Science:
- Neuroscience
- Biochemistry
- Developmental Biology
Background:
- The human brain undergoes extensive lipid remodeling during development.
- Understanding the dynamic changes in phospholipid and sphingolipid fatty acid composition is crucial for brain maturation.
Purpose of the Study:
- To investigate the developmental changes in the fatty acid composition of major phospholipids and sphingomyelin in the human forebrain.
- To correlate these changes with specific developmental stages, from prenatal to early postnatal years.
Main Methods:
- Analysis of phospholipid classes including phosphatidylethanolamine (PE), ethanolamine plasmalogens (EPs), phosphatidylserine (PS), phosphatidylcholine (PC), and sphingomyelin.
- Separation of phospholipids using two-dimensional thin-layer chromatography (2D-TLC).
- Quantification of fatty acid methyl esters (FAMEs) via capillary column gas-liquid chromatography (GLC).
Main Results:
- Docosahexaenoic acid (22:6n-3) increased with age in PE and PC; arachidonic acid (20:4n-6) remained relatively constant.
- In EPs, oleic acid (18:1n-9) and adrenic acid (22:4n-6) predominated postnatally.
- Sphingomyelin showed dramatic accretion of very long-chain fatty acids, particularly nervonic acid (24:1n-9), with advancing myelination.
Conclusions:
- Human brain lipid composition, especially fatty acid profiles in phospholipids and sphingomyelin, undergoes significant, age-dependent changes.
- These alterations reflect distinct developmental processes, including myelination and neuronal maturation.
- Specific fatty acids like 22:6n-3 and 18:1n-9 play critical roles in different lipid classes during brain development.
Abstract:
The fatty acid composition of phosphatidylethanolamine (PE), ethanolamine plasmalogens (EPs), phosphatidylserine (PS), phosphatidylcholine (PC), and sphingomyelin was studied in 22 human forebrains, ranging in age from 26 prenatal weeks to 8 postnatal years. Phospholipids were separated by two-dimensional TLC, and the fatty acid methyl esters studied by capillary column GLC. Docosahexaenoic acid (22:6n-3) increased with age in PE and PC, whereas arachidonic acid (20:4n-6) remained quite constant. In EP, 22:6n-3 increased less markedly than 20:4n-6, adrenic (22:4n-6) and oleic (18:1n-9) acids being the predominant fatty acids during postnatal age. In PS, 18:1n-9 increased dramatically throughout development, and 20:4n-6 and 22:4n-6 increased only until approximately 6 months of age. Although 22:6n-3 kept quite constant during development in PS, its percentage decreased due to the accretion of other polyunsaturated fatty acids (PUFAs). As a characteristic myelin lipid, sphingomyelin was mainly constituted by very long chain saturated and monounsaturated fatty acids. Among them, nervonic acid (24:1n-9) was the major very long chain fatty acid in Sp, followed by 24:0, 26:1n-9, and 26:0, and its accretion after birth was dramatic. As myelination advanced, 18:1n-9 increased markedly in all four glycerophospholipids, predominating in EP, PS, and PC. In contrast, 22:6n-3 was the most important PUFA in PE in the mature forebrain.