The Science of Cannabinoid Receptors
What are Cannabinoid Receptors
Cannabinoid receptors are one of the most important parts of the endocannabinoid system (ECS), which itself is responsible for regulating an impressive number of important biological functions. Whether you choose to use a Full Spectrum or a THC Free CBD product, its interaction with the ECS is what results in CBD's therapeutic effects.
Put simply, cannabinoid receptors are the part of the ECS that sense the presence of cannabinoids; once they detect cannabinoids, they send a signal to the cell, which provokes a metabolic response specific to the area in which the receptor is located.
Existing research suggests that cannabinoid receptors play a vital role in maintaining homeostasis, the balance of biological functions that promotes overall health. In this sense, cannabinoid receptors are important for ensuring that our blood pressure, hormone levels, and virtually every other metabolic process remains within a narrow, healthy range.
Types of Cannabinoid Receptors
There are currently two known forms of cannabinoid receptor, though existing research indicates that there are likely other types as well. These receptor types play similar roles, but their primary locations and precise functions are distinct.
CB1 receptors are located principally in the central nervous system (CNS). The vast majority of CB1 receptors are located in the brain, but studies have also found them present in the peripheral nervous system (PNS), which governs a wide variety of other bodily systems including the lungs, liver, kidneys, and reproductive organs. Depending on the species in question, the density of CB1 receptors in each system can vary significantly.
CB1 receptors were originally discovered in 1990, and subsequent research has determined that they play a role in memory formation and retention, motor functions, appetite regulation, perception of pain, sleep, and overall mood.
Activation of CB1 receptors has been shown to trigger a neuroprotective response in the body. This suggests that cannabinoids that interact with CB1 receptors may help to prevent or treat several neurodegenerative conditions, including Alzheimer’s disease, Parkinson’s disease, or multiple sclerosis.
CB2 receptors are located principally in the body’s immune and gastrointestinal systems, with the majority located in the immune system. They are also present in the brain, but much less densely than are CB1 receptors.
CB2 receptors were discovered in 1993. Current research into the role and function of CB2 receptors is not as well developed as research focused on CB1 receptors. However, several important CB2 functions have been observed.
Activation of CB2 receptors has been shown to trigger an anti-inflammatory response in the body. Inflammation is an important bodily response, but an over-active inflammatory response can cause profound problems in the body. These findings suggest that cannabinoids that interact with CB2 receptors may be beneficial for treating inflammation-related conditions, including Crohn’s disease, inflammatory bowel syndrome, and arthritis.
How do Cannabinoid Receptors Function
Cannabinoid receptors sit on the surface of many types of cells in the body, “listening” for the presence of cannabinoids. The body produces its own cannabinoids, known as endocannabinoids, which help cells in the body communicate with each other and trigger important reactions for maintaining overall health. However, cannabinoid receptors also react to the presence of other cannabinoids, including CBD, CBG, CBN, and other phytocannabinoids (cannabinoids produced by plants).
When a receptor reacts to the presence of endocannabinoids or phytocannabinoids, it reacts by spurring the cell into action. Depending on the receptor, its location, and the type of cannabinoid detected, the resulting action can vary significantly.
Broadly speaking, endocannabinoid receptors often have the effect of halting or otherwise reducing the activity of overactive cells that are sending problematic signals to other parts of the body. For example, consider the function of brain cells (neurons):
Typically, neurons communicate with each other and with other parts of the body by releasing chemicals, known as neurotransmitters. The neuron that sends the message (the presynaptic cell) releases a neurotransmitter, and the neurotransmitter then travels across a gap (the synapse) towards its target destination (the postsynaptic cell). The postsynaptic cell then receives the message and provokes an additional response.
In general, this communication between neurons is unidirectional, so the presynaptic cell has no way of knowing whether its message was received, or if the postsynaptic cell will respond in the intended way. Under certain circumstances, this lack of feedback can lead to problems; for instance, the presynaptic cell may become over-excited, repeatedly sending out redundant messages that can clog up the works and cause issues for neuronal communication. Resolving issues of this sort is one of the key functions of cannabinoid receptors, and of the ECS generally.
When a postsynaptic cell needs to communicate a message back to a presynaptic cell, it does so by creating and releasing endocannabinoids from lipid precursors (fat cells). These cannabinoids then travel back to the presynaptic cell and attach to a cannabinoid receptor. Depending on the cannabinoid received, this will slow, accelerate, or otherwise alter new signals sent out by the presynaptic cell. Because such signals reverberate out to other cells and body parts, the resulting effects can be wide-ranging, and account for the various differences caused by cannabinoids like CBD or THC.