REGIONAL LEVELS OF BRAIN PHOSPHOLIPASE C-GAMMA IN ALZHEIMERS-DISEASE

The levels of PLC gamma, a phospholipase C (PLC) isozyme, were higher in the cytosol fraction than in the membrane fraction in several contr ol brain regions. The levels of PLC gamma were significantly elevated in the membrane, but not in the cytosolic fraction of the hippocampus of AD subjects. In the superior and middle temporal gyri (SMTG) of AD subjects, the levels of PLC gamma were significantly elevated in both the membrane and cytosolic fractions. In the inferior parietal lobule and cerebellum of AD subjects, no significant changes were found in th e PLC gamma levels of either cytosolic or membrane fractions. These re sults suggest that the increased levels of PLC gamma, by increasing th e hydrolysis of PIP2 in the hippocampus and SMTG, may contribute to pa thophysiology of AD. These results also support a role for excitatory neurotransmitters and their receptors in AD. (C) 1998 Published by Els evier Science B.V. All rights reserved.