Discovery of the [11C]JHU75528 radioligand, a radioactive biochemical substance that is used to study the receptor systems of the brain, "opens an avenue for noninvasive study of central cannabinoid (CB1) receptors in the human and animal brain," explained Andrew Horti, assistant professor of radiology at Johns Hopkins Medicine, Baltimore, Md. He explained that there is evidence that CB1 receptors play an essential role in many disorders including schizophrenia, depression and motor function disorders. "Quantitative imaging of the central CB1 using PET could provide a great opportunity for the development of cannabinergic medications and for studying the role of CB1 in these disorders," added the co-author of "PET Imaging of Cerebral Cannabinoid CB1 Receptors with [11C]JHU75528."
Cannabinoid receptors are proteins on the surface of brain cells; they are most dense in brain regions involved with thinking and memory, attention and control of movement. The effects of tetrahydrocannabinol (THC), the primary psychoactive compound in marijuana, are due to its binding to specific cannabinoid receptors located on the surface of brain cells. "Blocking CB1 receptors presents the possibility of developing new, emerging medications for treatment of obesity and drug dependence including alcoholism, tobacco and marijuana smoking," said Horti.
The usefulness of in vivo (in the body) radioligands for studying cerebral receptors by PET depends on the image quality, and a good PET radiotracer must display a high level of specific receptor binding and low non-specif
Contact: Maryann Verrillo
Society of Nuclear Medicine