Phosphatidylserine (PS) is a phospholipid found in neuronal cell membranes that helps to support cognitive function. PS helps to maintain optimal levels of membrane fluidity, which is necessary for proper enzyme and receptor activities.  It also mediates the activity of several neurotransmitters, including norepinephrine, dopamine and serotonin.  In a randomized, placebo-controlled trial involving 73 elderly participants with mild memory impairment, daily supplementation with 300 mg of PS for 6 months significantly improved word recall rates.The improvement in cognitive function extended three months after the treatment period ended. PS can be metabolized into the choline-containing neurotransmitter acetylcholine, which can influence synaptic plasticity, the ability to strengthen the transmission at a synapse. Increases in synaptic plasticity are central to improving memory and learning. PS supplementation may increase brain-derived neurotropic factor, a protein that may influence the survival of neurons and may also have a role in enhancing memory and learning.