Glycerophospholipids in brain: their metabolism, incorporation into membranes, functions, and involvement in neurological disorders

Neural membranes contain several classes of glycerophospholipids which turn over at different rates with respect to their structure and localization in different cells and membranes. The glycerophospholipid composition of neur al membranes greatly alters their functional efficacy. The length of glycer ophospholipid acyl chain and the degree of saturation are important determi nants of many membrane characteristics including the formation of lateral d omains that are rich in polyunsaturated fatty acids. Receptor-mediated degr adation of glycerophospholipids by phospholipases A(1), A(2), C, and D resu lts in generation of second messengers such as arachidonic acid, eicosanoid s, platelet activating factor and diacylglycerol. Thus, neural membrane pho spholipids are a reservoir for second messengers. They are also involved in apoptosis, modulation of activities of transporters, and membrane-bound en zymes. Marked alterations in neural membrane glycerophospholipid compositio n have been reported to occur in neurological disorders. These alterations result in changes in membrane fluidity and permeability. These processes al ong with the accumulation of lipid peroxides and compromised energy metabol ism may be responsible for the neurodegeneration observed in neurological d isorders. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.