Cannabinoid receptor type 1, often abbreviated as CB1, is a protein found primarily in the brain and central nervous system. It plays a crucial role in the endocannabinoid system, which helps regulate various physiological processes, including mood, appetite, and pain sensation. CB1 receptors interact with naturally occurring compounds in the body, known as endocannabinoids, as well as with cannabinoids found in the cannabis plant. These receptors are involved in modulating neurotransmitter release, influencing how signals are transmitted between nerve cells. The activation of CB1 receptors can lead to various effects, such as reduced anxiety and increased appetite, making them a target for research in treating conditions like chronic pain and anxiety disorders.