Endogenous cannabinoids are naturally produced signaling molecules within the human body. These compounds resemble those found in the cannabis plant but are generated internally as part of a complex communication network that helps maintain the body’s stability.
Understanding the Endocannabinoid System
The effects of endogenous cannabinoids are exerted through the endocannabinoid system (ECS). This biological system’s primary role is to maintain homeostasis, which is the state of steady internal conditions required by living systems. Discovered in the early 1990s, the ECS regulates numerous bodily functions to maintain this balance.
The ECS is comprised of three core components that work together. The first are the endocannabinoids themselves, which act as the chemical messengers of the system. The second component is a series of receptors located on the surface of cells. The final part consists of enzymes, which create endocannabinoids when needed and break them down once their task is complete.
Major Endogenous Cannabinoids
Endogenous cannabinoids are lipid-based neurotransmitters, or fatty molecules that transmit signals between nerve cells. Unlike many other signaling molecules, they are not stored for later use. They are synthesized on-demand from lipid precursors within cell membranes, allowing for a rapid and localized response to physiological needs.
The two most studied endogenous cannabinoids are anandamide (AEA) and 2-arachidonoylglycerol (2-AG). Anandamide, discovered in the early 1990s, gets its name from the Sanskrit word for “bliss,” reflecting its role in mood regulation. 2-AG is more abundant in the brain than anandamide and is also a primary component of endocannabinoid signaling.
How Endocannabinoid Receptors Work
Endocannabinoids exert their influence by binding to specific cannabinoid receptors on the surface of cells. The two primary types are cannabinoid receptor type 1 (CB1) and cannabinoid receptor type 2 (CB2). This binding is like a key fitting into a lock, an action that initiates a response within the cell.
CB1 receptors are one of the most abundant receptor types in the brain and central nervous system. Their activation influences processes like memory, mood, motor control, and pain perception.
CB2 receptors are found predominantly on cells of the immune system and in peripheral tissues. When endocannabinoids bind to CB2 receptors, they modulate inflammatory responses and immune function.
The specific effect of an endocannabinoid depends on which receptor it binds to and its location in the body.
Enzymes: Regulating Endocannabinoid Activity
The activity of endogenous cannabinoids is controlled by enzymes that manage their synthesis and degradation. The degradation process is important because it ensures signals are terminated promptly. This prevents receptors from being overstimulated and maintains the precision of the system.
Two primary enzymes are responsible for breaking down endocannabinoids. Fatty Acid Amide Hydrolase (FAAH) is the main enzyme that degrades anandamide. Monoacylglycerol Lipase (MAGL) is primarily responsible for breaking down 2-AG. The activity of these enzymes influences the concentration and duration of endocannabinoids, making them a target for therapeutic research.
Impact on Bodily Functions and Health
The integrated action of endocannabinoids, receptors, and enzymes allows the ECS to influence many physiological processes. This system helps regulate sleep, appetite, pain, mood, memory, and immune responses. When the body is disrupted by injury or illness, the ECS works to bring it back to a state of balance. For example, endocannabinoids might be released in a spinal nerve to relieve pain or in immune cells to reduce inflammation.
Dysregulation in the ECS can contribute to various health issues. The theory of Clinical Endocannabinoid Deficiency (CECD) proposes that insufficient endocannabinoid levels may cause conditions like migraine, fibromyalgia, and irritable bowel syndrome. Reduced levels of anandamide have also been associated with post-traumatic stress disorder, suggesting that targeting the ECS to restore balance holds potential for addressing a range of health problems.