ABSTRACT
Research suggests that fundamental aspects of brain function depend on the adequate consumption and thus membrane levels of polyunsaturated fatty acids (PUFAs), particularly, eicosapentaenoic acid [EPA, 20:5(n-3)], docosahexaenoic acid [DHA, 22:6(n-3)] and also arachidonic acid [AA, 20:4(n-6)]. It has been shown that by increasing the incorporation of these fatty acids into membrane phospholipids several basic properties of the membrane are improved. PUFAs are integral
I. Introduction ........................................................................................................................ 1229 II. Schizophrenia .................................................................................................................... 1230 A. Membrane Lipid Defects .............................................................................................. 1230 a. Erythrocytes and Platelets ........................................................................................ 1230 b. Brain ......................................................................................................................... 1232 B. Pathological Consequences of Impaired Membrane Dynamics ................................... 1236 a. Decreased Membrane Fluidity ................................................................................. 1236 b. Increased Free Radical Production ........................................................................... 1236 c. Decreased Dopamine Transporter Receptor (DATR) ............................................... 1237 d. Serotonin Dysfunction .............................................................................................. 1238 C. Biochemical Mechanisms Underlying Decreased Membrane PUFAs ......................... 1238 a. Low Intake or Synthesis of Arachidonic Acid .......................................................... 1238 b. Decreased Fatty Acid Incorporation ......................................................................... 1239 c. Increased Phospholipids Degradation ...................................................................... 1239 d. Increased Lipid Peroxidation .................................................................................... 1239 D. Therapeutic Effects ....................................................................................................... 1240 a. Dietary Essential Fatty Acid Supplementation ......................................................... 1240 b. Atypical Antipsychotic Drugs ................................................................................... 1241 E. Summary ....................................................................................................................... 1242 III. Major Depression ............................................................................................................... 1243 A. Reduced Membrane PUFAs ......................................................................................... 1244 B. Pathological Consequence of Reduced Membrane n-3 PUFAs ................................... 1245 C. PUFAs and Immune Function ...................................................................................... 1246 D. Dietary Effects of PUFAs Supplementation ................................................................. 1247 IV. Other Psychiatric Disorders ............................................................................................... 1247 V. Conclusions ........................................................................................................................ 1248 References ................................................................................................................................. 1248
components of cell membrane lipids, primarily phospholipids such as phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine (PS), and phosphatidylinositol comprising 80% of total membrane phospholipids. The central nervous system is highly enriched in PUFAs, primarily AA and DHA (Salem et al., 2001). In addition to helping maintain normal membrane structure and function, PUFAs also are critical in all aspects of normal brain development and neurotransmission (Das, 2003; Casper, 2004).
