Scientists are improving the way PET scans work to detect diseases as early as possible with a new imaging agent. Focusing on PET scans used to detect neurological diseases, researchers from a new study show how PET radioligand “11C-Me-NB1” can improve imaging with PET technology.
Positron emission tomography (PET) scans use low levels of radioactive materials, also known as radioligands, to assess organ and tissue functions. The role of this test is to identify changes in the body at the cellular level to allow for early disease detection. During the PET scan, the radioligand is injected into the part of the body where researchers are testing for disease. It binds to a specific protein in the body and decays, a process which can be detected by the PET technology.
The new radioligand being investigated in the new study is designed to bind nerve cell proteins in the brain linked to learning and memory. Scientists believe this type of agent could improve detection, and ultimately treatment, of neurological diseases like Alzheimer’s, Parkinson’s, and multiple sclerosis.
When specific nerve cell proteins, called GluN1/GluN2B-containing N-methyl-D-aspartate (NMDA), are activated, levels of calcium in cells increases, often to a dangerous, potentially lethal point. This is why there are current treatments for neurological diseases that block NMDA receptors. The new 11C-Me-NB1 PET radioligand from the present study is the first to be able to facilitate imaging of the GluN2B receptor subunit of the NMDA receptor complex in humans.
"The availability of such a PET radioligand would not only help to better understand the role of NMDA receptors in the pathophysiology of the many brain diseases in which the NMDA receptor is implicated, but it would also help to select appropriate doses of clinically relevant GluN2B receptor candidate drugs,” explained Simon M. Ametamey, PhD. “Administering the right dose of the drugs to patients will help minimize side-effects and lead to improvement in the efficacy of the drugs."
Researchers tested the ability of 11C-Me-NB1 in a study with rats given a drug called eliprodil, which blocks the NMDA GluN2B receptor. Using PET scans, researchers hoped to use 1C-Me-NB1 to evaluate the dose and effectiveness of the drug.
They found that applying 11C-Me-NB1 with PET technology was able to identify “neuroprotective doses” of eliprodil.
"These results mean that a new radiopharmaceutical tool is now available for studying brain disorders such as Alzheimer's disease, Parkinson's disease and multiple sclerosis, among others,” Ametamey explained. “It joins the list of existing PET radiopharmaceuticals used in imaging studies to investigate and understand underlying causes of these brain disorders."
The present study was published in The Journal of Nuclear Medicine.