This invention provides methods of increasing or enhancing the synthesis and levels of phospholipids, synapses, synaptic proteins, and synaptic membranes by a neural cell or brain cell; methods of treating a subject with a memory disorder, memory impairment, neurological disorder, or brain disease or disorder, comprising administering to the subject a composition comprising an omega-3 fatty acid, an omega-6 fatty acid, uridine, a metabolic precursor thereof, or a combination thereof.