Trouble Ahead, Hole in the Road

You’re driving your car on the motorway until all at once you see an enormous hole in the road. It’s not possible to drive any further. You stop the car in annoyance and phone the Highways Department. The telephone rings a few times and then a friendly receptionist picks up the call. She listens patiently to your story and promises that someone will come out to where you are as soon as possible. She hangs up.

You wait patiently for the repair worker. And guess what, within a few seconds a repair worker drives up. He gets out in a hurry, grabs his tools and starts to repair the hole. You monitor in the meantime. As soon as the hole is repaired, you proudly continue on your way. No (serious) accidents have happened. No one drove into the hole, went off the road or had to take a diversion. The consequences of this could have been quite dramatic. So you drive on keeping an eye out for any other abnormalities along the way.

The Signalling Device in our Body

This situation is actually a simplified representation of what the endocannabinoid system does in our body. In this example you are the Endocannabinoid system; the signalling device for the hole in the road. The road in this case is our body at cellular level and the road patrol is our brain - the coordinating organisation which keeps a close eye on everything and keeps it under control. Because you - the endocannabinoid system - fire off a signal, the hole can be repaired. The hole in our body could be anything; something which has gone slightly wrong or doesn’t belong there. So this system controls certain processes in the body, such as pain, thoughts, inflammation, the immune system and cellular controls.

The endocannabinoid system does not itself repair any defects but signals the brain. This results in the required substances and reinforcements arriving at the defect on time. Before the damage is too much for the body itself to repair. The monitoring of possible defects happens very accurately, right down to cell level.

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How does the endocannabinoid system work?

The endocannabinoid system consists of endocannabinoids. Endo means internal to the body; the system consists of internal body signalling agents (neurotransmitters) which bind to a pair of receptors - CB1 and CB2 - in our body. Important endocannabinoids include Anandamide and Serotonin.

‘Key in the hole’ principle

Our body is constructed from cells. These cells have an interior and an exterior. The cell membrane separates the interior from the exterior. Receptors are proteins in the cell membrane where specific molecules can bind themselves. A familiar comparison is the ‘key in the hole’ principle. The signal molecules (keys) fit a number of receptors (keyholes).

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CB1 and CB2 Receptors

Because the signal molecules (keys) bind themselves to a receptor (the keyholes), the receptor can initiate a cellular response; information is transmitted from the one cell to the other cell.

Within our bodies there are a pair of receptors to which the endocannabinoids of the endocannabinoid system bind themselves:

  • CB1 receptors. These occur chiefly in our central nervous system and a number of organs. In this context, think of pain, nausea, memory, fine motor control, etc.
  • CB2 receptors. These occur chiefly in our immune system cells and peripheral organs.

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CBD and THC

The best-known substances which bind onto the CB1 and CB2 receptors are THC and CBD. These are the same substances which occur in cannabis and hemp plants. Note: each has a different effect. You get stoned or high from THC, whereas this is not the case with CBD. CBD reduces the psychoactive effects of THC.

All of Us Have It

A beautiful system: the endocannabinoid system. Every living creature - mammals, birds, fishes, certain molluscs, humans - enjoys such a system in his or her body. Even so, despite all of us having this, we still know very little about its existence.

Only Discovered in 1992

The scientists Allyn Howlet and William Devane discovered the very first cannabinoid receptors in a rat’s brain in 1988. After much follow-up research, it was only revealed at the beginning of the ‘90s that we - humans - had an entire network of cannabinoid receptors in our bodies: the endocannabinoid system. Consequently, our knowledge about this system is rather new and incomplete, and so there still remains a lot to learn about how it functions.