Extracellular matrix molecules, long-term potentiation, memory consolidation and the brain angiotensin system.
Considerable evidence now suggests an interrelationship among long-term potentiation (LTP), extracellular matrix (ECM) reconfiguration, synaptogenesis, and memory consolidation within the mammalian central nervous system. Extracellular matrix molecules provide the scaffolding necessary to permit synaptic remodeling and contribute to the regulation of ionic and nutritional homeostasis of surrounding cells. These molecules also facilitate cellular proliferation, movement, differentiation, and apoptosis. The present review initially focuses on characterizing the ECM and the roles of cell adhesion molecules (CAMs), matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs), in the maintenance and degradation of the ECM. The induction and maintenance of LTP is described. Debate continues over whether LTP results in some form of synaptic strengthening and in turn promotes memory consolidation. Next, the contribution of CAMs and TIMPs to the facilitation of LTP and memory consolidation is discussed. Finally, possible roles for angiotensins, MMPs, and tissue plasminogen activators in the facilitation of LTP and memory consolidation are described. These enzymatic pathways appear to be very important to an understanding of dysfunctional memory diseases such as Alzheimer's disease, multiple sclerosis, brain tumors, and infections.
Wright
John W
JW
Department of Psychology, Washington State University, PO Box 644820, Pullman, WA 99164-4820, USA. wrightjw@wsu.ed
Kramár
Enikö A
EA
Meighan
Starla E
SE
Harding
Joseph W
JW
D000809:Angiotensins / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000378:metabolism*; D002448:Cell Adhesion; D005109:Extracellular Matrix / Q000378:metabolism*; D006023:Glycoproteins / Q000378:metabolism; D006801:Humans; D007858:Learning; D017774:Long-Term Potentiation; D020782:Matrix Metalloproteinases / Q000378:metabolism; D008568:Memory; D008954:Models, Biological; D009420:Nervous System / Q000378:metabolism; D011509:Proteoglycans / Q000378:metabolism; D013997:Time Factors; D019714:Tissue Inhibitor of Metalloproteinases / Q000378:metabolism
D000809:Angiotensins; D006023:Glycoproteins; D011509:Proteoglycans; D019714:Tissue Inhibitor of Metalloproteinases; D020782:Matrix Metalloproteinases