ABSTRACT
I. Introduction .....................................................................................................355 II. Transport of Folate in the Central Nervous System ..................................... 356 III. Folate Metabolism in the Central Nervous System .......................................358 IV. Basic Mechanisms of Folate De ciency ....................................................... 359
A. Impaired Methylation-Dependent Pathways in the Central Nervous System ..........................................................................360 1. Studies on Cerebrospinal Fluid Folate
and Methylation Metabolites ............................................................... 362 2. Protein Methylation in the Central Nervous System ............................363 3. DNA Methylation and Transcription ...................................................364 4. Methylation of Phospholipids ................................................................366
