Dietary uridine enhances the improvement in learning and memory produced by administering DHA to gerbils.
This study examined the effects on cognitive behaviors of giving normal adult gerbils three compounds, normally in the circulation, which interact to increase brain phosphatides, synaptic proteins, dendritic spines, and neurotransmitter release. Animals received supplemental uridine (as its monophosphate, UMP; 0.5%) and choline (0.1%) via the diet, and docosahexaenoic acid (DHA; 300 mg/kg/day) by gavage, for 4 wk, and then throughout the subsequent period of behavioral training and testing. As shown previously, giving all three compounds caused highly significant (P<0.001) increases in total brain phospholipids and in each major phosphatide; giving DHA or UMP (plus choline) produced smaller increases in some of the phosphatides. DHA plus choline improved performance on the four-arm radial maze, T-maze, and Y-maze tests; coadministering UMP further enhanced these increases. (Uridine probably acts by generating both CTP, which can be limiting in phosphatide synthesis, and UTP, which activates P2Y receptors coupled to neurite outgrowth and protein synthesis. All three compounds also act by enhancing the substrate-saturation of phosphatide-synthesizing enzymes.) These findings demonstrate that a treatment that increases synaptic membrane content can enhance cognitive functions in normal animals.
Holguin
Sarah
S
Massachusetts Institute of Technology, 43 Vassar St., 46-5023, Cambridge, MA 02139, USA.
Martinez
Joseph
J
Chow
Camille
C
Wurtman
Richard
R
D000818:Animals; D001522:Behavior, Animal; D001923:Brain Chemistry / Q000187:drug effects*; D002794:Choline / Q000494:pharmacology; D003570:Cytidine Triphosphate / Q000096:biosynthesis; D004032:Diet; D004281:Docosahexaenoic Acids / Q000494:pharmacology*; D005849:Gerbillinae; D008082:Lipotropic Agents / Q000494:pharmacology; D008297:Male; D018782:Maze Learning / Q000187:drug effects*; D008568:Memory; D009419:Nerve Tissue Proteins / Q000096:biosynthesis*; D016501:Neurites / Q000378:metabolism; D014176:Protein Biosynthesis / Q000187:drug effects; D058910:Purinergic P2 Receptor Agonists; D018048:Receptors, Purinergic P2 / Q000378:metabolism; D013570:Synaptic Membranes / Q000378:metabolism; D013997:Time Factors; D014542:Uridine Monophosphate / Q000494:pharmacology*; D014544:Uridine Triphosphate / Q000096:biosynthesis
D008082:Lipotropic Agents; D009419:Nerve Tissue Proteins; D058910:Purinergic P2 Receptor Agonists; D018048:Receptors, Purinergic P2; D004281:Docosahexaenoic Acids; D003570:Cytidine Triphosphate; D014542:Uridine Monophosphate; D002794:Choline; D014544:Uridine Triphosphate