Cannabinoids are a diverse group of chemical compounds that function as signaling compounds. They interact with specific receptor systems found throughout the body in humans and nearly all other animals. While most commonly associated with the Cannabis sativa plant, they are not exclusive to it. Their primary role is to modulate how cells communicate, fine-tuning the body’s internal messaging systems. This influences a broad range of biological processes, including mood, memory, appetite, and pain perception.
Classifying Cannabinoids by Origin
Cannabinoids are grouped into three main categories based on their source of origin. This classification provides a framework for understanding where the molecules come from.
Phytocannabinoids are compounds derived directly from plants, such as the cannabis species. Hundreds of these have been isolated, making them the most widely recognized group.
Endocannabinoids are compounds produced naturally within the mammalian body. These internal, lipid-based molecules function as part of a pervasive regulatory system.
Synthetic cannabinoids are laboratory-created compounds. These manufactured molecules mimic the effects of phytocannabinoids, often binding to the same receptors but sometimes having more potent effects.
The Major Plant-Derived Compounds
Phytocannabinoids are the most studied group, with four compounds notable for their abundance and distinct characteristics.
Delta-9-tetrahydrocannabinol (THC) is the most well-known, recognized as the principal psychoactive component. THC achieves its intoxicating effects by binding to receptors in the brain and central nervous system, altering perception and stimulating appetite.
Cannabidiol (CBD) is the second most common phytocannabinoid and is non-intoxicating. Unlike THC, CBD does not produce a “high” and is researched for its anti-inflammatory and anxiety-reducing properties. CBD may work by preventing the breakdown of the body’s own endocannabinoids, allowing them to have a greater effect.
Cannabigerol (CBG) is often referred to as the “mother” or precursor cannabinoid. In the plant, cannabigerolic acid (CBGA) is the compound from which THC, CBD, and other cannabinoids are synthesized. CBG is mild, non-intoxicating, and may offer anti-inflammatory and neuroprotective effects.
Cannabinol (CBN) is a minor cannabinoid and a degradation product of THC. When THC is exposed to heat, oxygen, and light, it converts into CBN. This compound is mildly psychoactive, less potent than THC, and has been researched for its sedative properties.
How Cannabinoids Interact with the Body
The effects of all cannabinoids are mediated by the Endocannabinoid System (ECS). This complex internal network is present in all mammals and maintains biological balance, or homeostasis, across many bodily functions. The ECS comprises three main components: endocannabinoids, the enzymes that process them, and cannabinoid receptors.
Cannabinoid Receptors
The primary targets are the G-protein coupled receptors, specifically Cannabinoid Receptor Type 1 (CB1) and Cannabinoid Receptor Type 2 (CB2). CB1 receptors are found predominantly in the brain and central nervous system, influencing cognitive function, memory, and pain modulation. When activated, CB1 receptors inhibit the release of certain neurotransmitters, regulating activity in the nervous system. CB2 receptors are found mainly in the peripheral nervous system, concentrated in immune cells and tissues. Their activation modulates inflammation and immune response. Phytocannabinoids like THC bind to and activate these receptors, producing their distinct effects.
The Role of Internal Cannabinoids
Endocannabinoids are lipid messengers produced on demand by cells to regulate short-range signaling processes. The two most characterized internal cannabinoids are Anandamide (AEA) and 2-Arachidonoylglycerol (2-AG). These molecules are synthesized from fatty acids and act as natural ligands for the CB1 and CB2 receptors.
Anandamide, sometimes called the “bliss molecule,” is a partial agonist at both receptors. It plays a role in modulating memory consolidation and anxiety responses. AEA also interacts with non-cannabinoid receptors, such as TRPV1, which are involved in pain and temperature regulation.
2-Arachidonoylglycerol (2-AG) is generally present in higher concentrations than anandamide in the brain. It acts as a full agonist at both CB1 and CB2 receptors. 2-AG is thought to be the primary mediator of synaptic plasticity, which is the ability of synapses to strengthen or weaken. The rapid synthesis and breakdown of these compounds ensure their signaling effects are tightly controlled and localized.