What are CB1 and CB2 Receptors? Where are they located?
CB1 and CB2 Receptors are found within the human body.
In general. they form part of the endocannabinoid system (ECS). This system is responsible for regulating many functions in our body e.g. sleep, temperature, memory, learning, immune responses etc.
What do Receptors Do and How Do They Do it?
By and large receptors send and receive ‘signals’. Thereby they help modulate and balance numerous bodily systems.
Interestingly the ‘signals’ used are known as Neurotransmitters. Notably, these are the ‘messengers’, that send different signals around the body.
As a matter of fact, there are two important endocannabinoids both naturally produced within the human body: AEA – Anandamide (arachidonoyl ethanolamide) and 2-AG – 2-archidonoyl glycerol.
These ‘messengers’ interact with the CB1 and CB2 receptors, creating specific responses within different cells.
CB2 = Cannabinoid receptor type 2
Note: Cannabinoids interact with specific receptors, namely: CB1 and CB2
Receptor located on the Cell Membrane
Movement of endocannabinoids, at the receptor site. These 'messengers' interact with receptors. Resulting in different specific responses within different cells.
Locations of CB1 and CB2 Receptors
(Above) CB2 is mainly focused on anti-inflammatory and immunosuppressive actions. Whereas CB1 helps control and regulate transmission of neurones and a range of processes, including memory, pain, inflammation etc.
CB1
For the most part, CB1 receptors are located in the: brain, central nervous system, lungs, liver, kidneys and even skin.
As such, CB1 receptors include regulation of a range of brain functions via neurotransmitters.
What is the impact of CBD on CB1 Receptors?
Firstly a couple of definitions to help you:
Agonist – A substance that not only binds to a receptor, but also activates the receptor, producing the intended response.
Antagonist – A substance that binds to the receptor, preventing the receptor from sending out a response.
To note: CBDs do not activate CB1 receptors. Interestingly, CBDs have been shown to block cannabinoid receptors and help slow down activities. In a word – they are ‘antagonist’.
How do the body’s naturally-produced cannabinoids interact with CB1 Receptors?
In fact, anandamide (AEA – a naturally produced cannabinoid in the human body), happens to be a partial agonist for cannabinoid CB1 receptors.
In other words, it only partially activates receptors, depending on various molecular mechanisms at exist that time and location.
In contrast, 2-archidonoyl glyerol (2-AG – another naturally produced cannabinoid in the human body), is a full agonist.
To clarify, it activates the CB1 receptor.
Example: When Inflammation Occurs
(Above) CB2 Receptors are located in immune related tissues. Once activated, signals are sent out to help regulate inflammation
What is the resulting effect of THC on CB1 Receptors?
Interestingly, THC targets CB1 receptors, that can result in euphoric and psychotropic effects.
Dopamine transmission occurs when THC comes into contact with the receptor, often resulting in a ‘high’ feeling.
(Note: Dopamine is a neurotransmitter that creates a feeling of pleasure).
CB2
In contrast CB2 receptors can be found in immune-related tissues. Interestingly they appear in the brain when an injury or inflammation occurs. CB2 receptors are mostly located on immune cells that move around the blood stream. Once the CB2 is activated it will send out signals that help regulate inflammation, as well as help repair cells.
Another key point, is that when an injury occurs, or resulting inflammation kicks-in, CB2 receptors can be found in the brain. It is worthy of note that the presence of CB2 helps reduce inflammation ‘signals’. In turn, this may help return the body back to its normal state.
Being that CBDs are antagonistic by nature, they’re more likely to limit responses from CB2 receptors.
Are there any other cannabinoid receptors in the human body?
Now that’s an interesting question! There may well be another, third receptor, however, it’s still early days in the land of cannabinoid research. We hold our breath in anticipation of new discoveries.
