CB2 Receptors in the Brain
It is commonly believed that CB1 receptors are expressed in the nerves and brain, while CB2 receptors are found on other types of cells (immune and somatic). This belief is somewhat true, but can be misleading.
The nerves and brain do have more CB1 receptors than CB2. But CB2 receptors are not entirely absent from the brain. A 2006 study from William Patterson University found that CB2 receptors are widely distributed in the brain, but only in association with glial cells. The glial cells are speciallized macrophages, immune cells that are sometimes seen as support cells. The study suggested that their presence might present new possibilities for treating conditions like depression and substance abuse. 1
The Glia serve a number of functions:
- Physical support
- The supply of nutrients and oxygen
- Separation - physical barriers
- Engulfing invaders
- Removal of dead neurons
- Modulating the activity of nerve cells
A variety of chronic neurological conditions (Alzheimer's disease, Parkinson's disease, ALS, depression, schizophrenia, etc) might benefit from stimulation of CB2 receptors attached to nerve cells.
- Discovery of the presence and functional expression of cannabinoid CB2 receptors in brain.
- Brain cannabinoid receptor 2: expression, function and modulation.
- Cannabinoid CB2 receptors modulate midbrain dopamine neuronal activity and dopamine-related behavior in mice.
- Progress in brain cannabinoid CB 2 receptor research: From genes to behavior.