Cannabinoid type 1 receptors in astrocytes

Published on December 2, 2014   37 min

A selection of talks on Biochemistry

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My name is Giovanni Marsicano. I'm group leader of the group EndoCannabinoids and NeuroAdaptation at the NeuroCentre Magendie in Bordeaux. And I'm very happy today to present you some ideas and some recent data on the role of cannabinoid receptor type 1 in astrocytes in the brain.
So first, a little introduction about endocannabinoid system and cannabinoid receptors. As many people know in the world, the plant Cannabis sativa, or marijuana, has profound effects on the brain, on the body, and this is been known by human beings since many thousands of years. And actually, this plant has many records because it is the first plant that has been likely cultivated for reasons independent from food intake, from eating. And also, it's been considered one of the first, let's say, sacred drugs because of its psychotropic effects. However, this long history of a relationship between the plant Cannabis sativa and human beings has not been clarified from the scientific point of view until the middle of the '60s when the group of Raphael Mechoulam, in 1964, identified the compounds present in the plant and identified about 60 compounds that are all, more or less, biologically active. The most psychoactive compound of the plant is the famous delta-9 tetrahydrocannabinoid or so-called THC. However, how THC is acting in the brain and in the body was still a mystery for a couple of decades until the late '80s and beginning of the '90s when the first cannabinoid receptor, called CB1 for cannabinoid receptor type 1, was identified and cloned and identified as seven transmembrane G-protein coupled receptor. At this point, as you can see here, we have an exogenous ligand, THC, and an endogenous receptor. Of course, we miss a part of the puzzle. That is, what is physiologically activating CB1 receptors? And for this, we just needed to wait a couple of years, until 1992, when the same group of Raphael Mechoulam in Israel identified the first endocannabinoid, so called anandamide. The name is derived from the Sanskrit word "ananda," which means bliss. So they called it an amide of bliss. And as you see, both THC and endocannabinoids are lipid compounds, which is also an interesting aspect of this system, a system that at this point we can identify with an endogenous receptors and endogenous ligands. And we have a so-called endocannabinoid system which is involved, really, in a plethora of functions. This is a very limited list of functions of the endocannabinoid system has been implicated in. There are many more.