Science for Potheads: Why People Love to Get High

There's so much misunderstanding around marijuana. Here's what's really happening to people when they smoke weed.

Photo Credit: Shutterstock.com/Atypeek Design

September 12, 2013  |  

  

Drug warriors have long tried to smear marijuana as a dangerous scourge, seeking to criminalize possession of a leaf they clearly do not understand. The key to comprehending its effects is by better grasping our physiology.

Marijuana is not magic. Marijuana (botanical name,  cannabis) affects the human body because the plant-based cannabinoids in marijuana, once ingested, can “plug into” the cannabinoid receptors that are used by the cannabinoids made by our own bodies.

It’s not just people that have cannabinoid systems. All mammals have them. All creatures do, except bugs. Although cannabinoid systems can utilize the plant-based cannabinoids in marijuana, the cultivation and preservation of cannabinoid systems by the evolutionary process has nothing to do with pot.  The cannabinoid receptor appeared on the planet at least 550 million years before marijuana.

Evolution has selected for cannabinoid systems, meaning once they emerged, they were retained, and broadly adopted. A cannabinoid system must make living here on this planet easier, or even possible, for those who have them. That’s why life cultivates and retains certain mutations, such as fins, eyes or bigger brains. They’re useful, or at least once were. Why would the cannabinoid system be any different?

The cannabinoid receptor seems to have first appeared approximately 600 million years agoin sea squirts. Sea squirts also happen to be our closet relatives among the invertebrates.  We share 80 percent of our genes with them.

A sea squirt is a tunicate, and tunicates contain a host of potentially useful chemical compounds that are effective against various types of cancer. In the May 2007 issue of The Federation of American Societies for Experimental Biology (FASEB) Journal, researchers from Stanford University showed that “tunicates can correct [biological] abnormalities over a series of generations… the mechanisms underlying the phenomenon may lead to insights about the potential of cells and tissues to be reprogrammed.”

Could that underlying mechanism allowing for “reprogramming” involve the cannabinoid system?

Tunicates evolved in the early Cambrian period, a period that featured the Cambrian explosion that was characterized by increased diversity and diversification of organisms by an order of magnitude. The Cambrian explosion marked the sudden (in geological terms) emergence of almost every biological type known.

Prior to 580 million years ago, life forms were simple. Over the following 75 million years the rate of evolution accelerated. Charles Darwin considered the Cambrian explosion one of the best arguments against his theory of natural selection. Paleontologists Stephen Jay Gould and Niles Eldridge’s theory of  punctuated equalibria challenged the idea that evolution took place exclusively gradually over the generations and asserted that instead there were eras where rapid change ensued. Gould pointed to stasis in most of the fossil record for evidence.

Could there be a connection between an accelerated rate of evolution 580 million years ago and the emergence of the cannabinoid system 600 million years ago? Is it possible that it is a system involved with evolution itself?

The capacity to change is essential to survival. Grow a fin. Resist bacteria. Accept a new idea. The ability to change can mean the difference between life and death, at the individual level or for a species. We know we can change biochemically. There has to be a biochemical reason for that. Such a biochemical system would be mandatory for most species when it comes to survival in a changing world.

The cannabinoid system seems at least in part to be associated with the capacity to “shift,” i.e., change, dislodge stagnancies and interrupt patterns (“forget”). Memory is not just an act of the mind. The body has memory, too.  Marijuana affects “memory by way of the receptors in the limbic system’s hippocampus, which “gates” information during memory consolidation.”

http://www.alternet.org

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