Anandamide

Anandamide, also known as arachidonylethanolamide or arachidonoylethanolamine or AEA, is a naturally occurring endogenous cannabinoid neurotransmitter found in the brain of animals, as well as other organs. It was isolated, and its structure elucidated by William Devane and Lumír Hanuš in the Laboratory of Raphael Mechoulam, at the Hebrew University in Jerusalem in 1992. The name is taken from the Sanskrit word ananda, which means "bliss", and amide.

Anandamide receptors
Anandamide's effects can be either central, in the brain, or peripheral, in other parts of the body. These distinct effects are mediated by the CB1 receptor in the nervous system, and the CB2 receptor in the periphery. The latter is mainly involved in functions of the immune system.

These receptors are part of the largest known family of receptors, the G protein-coupled receptors, which - in this case - has a distinctive pattern in which the receptor molecule spans the cell membrane seven times over. The CB1 receptor is one of the most numerous in the nervous system.

Anandamide receptors were originally discovered as being sensitive to Δ9-tetrahydrocannabinol (Δ9-THC), which is among the psychoactive cannabinoids found in cannabis. The discovery of anandamide came from research into CB1 and CB2, as it was inevitable that a naturally occurring (endogenous) chemical would be found to affect these receptors.

Anandamide receptors have been shown to be involved in the management of short term memory. Studies are under way to explore what role anandamide plays in human behavior, such as eating and sleep patterns, and the part it plays in pain relief.

Anandamide is also important for implantation of the early stage embryo in its blastocyst form into the uterus. Therefore cannabinoids like Δ9-THC might interfere with the earliest stages of human pregnancy.

Moreover, anandamide is thought to be an endogenous ligand for vanilloid receptors (which are involved in the transduction of acute and inflammatory pain signals), activating the receptor in a PKC-dependent (protein kinase C-dependent) manner.

Endogenous and dietary sources
Endogenous cannabinoids occur in minute quantities in cocoa (fermented Theobroma cacao) beans, in sea urchin roe, and in chocolate, though there is some controversy over whether they have any effects on the body in these quantities.

The human body synthesizes anandamide from arachidonic acid (AA) and ethanolamine. Studies of piglets show that dietary levels of AA and other essential fatty acids affect the levels of anandamide and other endocannabinoids in the brain.