INVOLVEMENT OF GLUTAMATE RECEPTORS, LIPASES, AND PHOSPHOLIPASES IN LONG-TERM POTENTIATION AND NEURODEGENERATION

Glutamate is the primary excitatory amino acid in the mammalian centra l nervous system. Normal excitation of glutamate receptors initiates t he stimulation of phospholipases and lipases with the generation of se cond messengers that are necessary for normal cell function. The overs timulation of glutamate receptors can initiate a cascade of biochemica l events including stimulation of membrane phospholipid turnover, exce ssive calcium entry, abnormal phosphorylation, and proteolysis. These events may be responsible for neuronal injury and degeneration found i n Alzheimer disease, ischemia, spinal cord trauma, epilepsy, and Hunti ngton disease.