Those interested in medical cannabis will remember that the CB1 receptors, discovered less than 20 years ago, are activated by THC and other cannabinoids in cannabis. This activation provides the psychoactive effects of cannabis and also some of its other health enhancing properties. CB receptors also respond to endocannabinoids produced by own bodies, primarily in our nerve cells. The receptors are part of the endocannabinoid receptor (or regulatory) system, now seen as a major physiological system, with important roles in pain relief, neuroprotection and anti-inflammation, even digestion and vision.
Such CB1 activation by THC from the plant world or anandamide from our own cells, along with other cannabinoids produced by the cannabis plant or our own bodies, can provide profound health benefits. Cannabinoids also work by activating CB2 receptors (primarily found on immune cells). Independent of their actions on receptors, cannabinoids are anti-oxidants, protecting nerve cells and other tissue from oxidation stress.
In the photo below, the CB1 receptors are being marked by the inverse agonist, 18F]MK-9470, a positron emission tomography (PET) tracer for in vivo human PET brain imaging of the cannabinoid-1 receptor. Inverse agonists tend to cause receptors to respond in ways opposite their response to agonists such as THC and anandamide. In the case of cannabinoid receptors, hope that inverse agonists might serve as obesity control agents has faded with problems from nausea and mood disturbances.
The physics of what goes on during such as PET scan it astounding. The process would appear to be highly hazardous to health, yet the procedure is commonplace and apparently without risk. Markers with affinities for certain cell types, such as the compounds used above, MK-9470, emit anti-matter. A positron is the anti-matter equivalent of an electron. When it is emitted from the source, in this case on a CB1 receptor in the brain, it travels only a short distance, a millimeter or so, before encountering its matter equivalent, an electron.
When matter electron and antimatter positron meet, the result is annihilation. Such an encounter releases a short burst of highly energetic photons in the form of gamma rays. Why matter/antimatter annihilation with accompanying gamma ray burst inside the brain is not fatal is not exactly clear. Perhaps a high-energy physicist could comment. Or even a low-energy physicist after coffee.
During this positron emission tomography, sensors detect where the gamma rays are coming from and map these in a 3D representation of brain anatomy and activity. In the images above the patterns of gamma rays being emitted from this matter/antimatter annihilation show the relative distributions of CB1 receptors in various parts of the human brain. See the original research for more detail. Although they are most highly concentrated in the brain, CB1 receptors are also found throughout the entire human body, mainly on nerve cell membranes.
Tags:
Anandamide, antimatter, cannabinoids, cannabis, CB1, CB2, endocannabinoid receptor, endocannabinoid receptor system, phytocannabinoids, positron, THC
In Jerusalem in the year 1992, Ananda, the Sanskrit word for bliss, named a newly identified molecule. Anandamide was given as name to the cannabinoid molecule first discovered being produced in the human body, that is, the first endocannabinoid. This revelation solved a decade’s old mystery. The discovery of anandamide and the receptor system it stimulates has greatly changed and grown our knowledge of the structure and functioning of our human bodies. What has been learned already offers to better our health and well-being.
A mystery and a great discovery.
The great discovery begins wrapped in a mystery: In the mid 1960’s researchers in Israel identified the active component of the plant Cannabis Sativa. Then, over a quarter century later, in 1990, researchers indentified natural receptors activated by this plant cannabinoid. The discovery of these receptors found them first in the brain, then throughout the human body.
The mystery: Why should human beings have a natural receptor system triggered by molecules from the flowers of a plant?
The discovery of the human cannabinoid receptor system and the natural substances that activate this system extends our knowledge of human body and its workings. The beneficial properties associated with the activation and modulation of this newly found system are profound: They offer a whole host of beneficial physiological functions including preventative and curative effects for many commonly afflicting diseases. Medicine in the 21st century will be fundamentally altered by the discovery of this system and the natural molecules we produce to manage it.
Jerusalem Journey
Jerusalem is sacred ground in many ways. It is central to three of the world’s most influential religions, and home to many of their key relics, both present and long past. The Wailing Wall, The Dome of the Rock and the Garden Tomb keep uneasy company with each other and with the ghosts of ancient structures, such as the Second Temple, twenty centuries ago burned to ash by the legions of Rome.
During all these thousands of years of Jerusalem history, back 1,000 years to the Crusades, back 2.000 years to the time Christ walked the city’s streets, and much further back, thousands of more years back, something else was constant in the land. Down these long centuries, humans were cultivating, trading and using a weedy plant across the Middle East of which Jerusalem is the center. The fast growing cannabis sativa provided its cultivators with useful fiber, nutritious seeds, potent medications and perhaps even helped stoke their spirituality.
Dr. Raphael Mechoulam’s discoveries began when he undertook the investigation of the active components of cannabis sativa, the plant so long used in the Middle East for relieving aches and pains, inflammation and a score of other ails, and for enjoying its bliss-giving properties. He began by securing a chunk of hashish, concentrated products of the flowering female plant. In 1964 at the Weissmann Institute of Science at the Rehovoth campus of Hebrew University, he and his team discovered the major active ingredient in cannabis, THC.[i]
But that is the story of a later post.
[i] Gaoni, Y.; Mechoulam, R.
Isolation, structure, and partial synthesis of an active constituent of hashish. J. Am. Chem. Soc. 1964,
86, 1646-1650.
