Your Brain Already Makes Its Own Cannabinoids. Here's How the System Works.

The endocannabinoid system (ECS) is one of the most widespread signaling networks in the brain. It operates through two primary endocannabinoids — 2-arachidonoyl glycerol (2-AG) and anandamide — that act as retrograde messengers, meaning they signal backward across synapses to regulate how much neurotransmitter gets released. CB1 receptors, the main targets, are among the most abundant receptors in the brain.

Despite their structural similarities, 2-AG and anandamide are made and broken down by entirely different enzyme pathways, giving them distinct biological roles. THC from cannabis mimics these molecules, binding to the same receptors but without the precise timing and location control that endocannabinoids use. The review also examines how this system appears disrupted in schizophrenia, where altered endocannabinoid signaling may contribute to the condition.

You can't understand what cannabis does to the brain without understanding the system it acts on. This review lays out the machinery: the receptors, the molecules, the enzymes, and the feedback loops. When someone uses cannabis, THC doesn't create new effects from scratch — it takes over an existing system that normally regulates neural communication with precise timing. Cannabis essentially floods a signaling network designed for brief, targeted bursts.

The distinction between 2-AG and anandamide matters because it means the endocannabinoid system isn't one thing — it's at least two overlapping systems with different jobs. Drugs that target one pathway may have very different effects than drugs targeting the other.