Neuronal Membrane Lipids – Their Role in the Synaptic Vesicle Cycle

Abstract

Endocannabinoids are amides, esters, and ethers of long-chain polyunsaturated fatty acids, which act as endogenous agonists of cannabinoid receptors. Thus, they are able to mimic several pharmacological effects of Δ9-tetrahydrocannabinol, the psychoactive principle of Cannabis sativa preparations like hashish and marijuana. Anandamide (N-arachidonoylethanolamine) and 2-arachidonoylglycerol are the best-studied members of this new class of lipid mediators. It is now widely accepted that the biological activity of endocannabinoids is largely dependent on a “metabolic control,” which modulates the effects of these substances by modulating their in vivo concentration. Therefore, the metabolic routes that allow synthesis, transport, and degradation of endocannabinoids, and that altogether form the so-called “endocannabinoid system,” are the focus of intense research. This new system will be reviewed in the chapter, along with the molecular targets of endocannabinoids, and the signal transduction pathways triggered thereof. The aim of this update is also to put in a better perspective the cross-talks of endocannabinoids with other signaling molecules, and their implications for the manifold biological activities of these lipids within the central nervous system.