California Cannabis Research Medical Group


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Autumn 2005
Journal of the California Cannabis Research Medical Group

Cloning the Receptor

The existence of cannabinoid receptors in the brain —proteins on the outside of certain cells to which cannabinoids bind, triggering a cascade of molecular events within the cells— was established in 1988 by Alynn Howlett (right) and William Devane at St. Louis University. Researchers were astonished to find that these receptors, now known as CB1 receptors, are at least 20 times more prevalent in the brain than opioid receptors.

A cell contains hundreds of thousands of protein molecules. The cell membrane is made of fat (lipid). If the cell were as big as a house, a protein would be as big as, say, a scissors or a doorknob.

A receptor is a protein on the surface of a cell that binds to something else. The something else is known as a “ligand” or an “agonist.” Neurotransmitters, hormones, and drugs are smaller than proteins by a factor of 1:5 or 1:10 (they have many fewer atoms than a protein).

The neurotransmitter floats around in the bloodstream and hooks onto receptors that bind to it specifically. The receptor has contact with both the outside and the inside of the cell (like a doorknob that, being twisted on the outside, twists on the inside.) The receptor mediates between the outside signal and what happens inside the cell.

The job of DNA is to store the directions for how to make all the proteins in our cells. To clone a receptor means you’ve located and can copy the gene —the section of DNA— that encodes it.

CB1 receptors are concentrated in the cerebellum and the basal ganglia (regions responsible for motor control, which may explain why marijuana reportedly eases muscle spasticity); in the hippocampus (storage of short-term memory); and in the limbic system (emotional control). Cannabinoids acting through the CB1 receptors seem to play a role in the processes of reward, cognition, and pain perception, as well as motor control.

O'Shaughnessy's is the journal of the CCRMG/SCC. Our primary goals are the same as the stated goals of any reputable scientific publication: to bring out findings that are accurate, duplicable, and useful to the community at large. But in order to do this, we have to pursue parallel goals such as removing the impediments to clinical research created by Prohibition, and educating our colleagues, co-workers and patients as we educate ourselves about the medical uses of cannabis.
The Society of Cannabis Clinicians (SCC) was formed in the Autumn of 2004 by the member physicians of CCRMG to aid in the promulgation of voluntary standards for clinicians engaged in the recommendation and approval of cannabis under California law (HSC §11362.5).

As the collaborative effort continues to move closer to issueing guidelines, this site serves as a public venue for airing and discussing these guidelines.

Visit the SCC Site for more information.