SeraBella (Formerly Phosphatidyl Serine)Item Description Phosphatidylserine is the most abundant phospholipid in the human brain and is made by the body in small amounts. This important phospholipid supports neuronal cell integrity by providing the building blocks needed for cell membrane structure and function.* Cell membranes not only act as a barrier between the inside and outside of a cell, but also play an important role in cellular communication and normal cellular responses.