Serotonin Receptor Is Reduced in Panic Disorder
June 03, 2004
Brain scans have revealed to researchers that in patients with panic disorder, a type of serontonin receptor is reduced by almost one-third in three structures straddling the center of the brain. The findings were reported in the January 21, 2004, issue of the Journal of Neuroscience.
In the current study, researchers used positron emission tomography (PET) scans to visualize serotonin receptors in brain areas of interest in 16 panic disorder patients, seven of whom also suffered from major depression, and 15 matching controls. A radioactive tracer binds to the receptors, revealing their location and a numerical count by brain region. Subjects also underwent structural magnetic resonance imaging (MRI) scans, which were overlaid with their PET scans to precisely match it with brain structure. The new finding of serotonin receptor reduction is the first to show that the receptor may be abnormal in the disorder and may help to explain how genes might influence vulnerability. Genes, for example, might increase risk for the disorder by coding for decreased expression of the receptors.
In a related study, recent experiments with knockout mice showed that a popular serotonin selective reuptake inhibitor (SSRI) drug produces its anti-anxiety effects by stimulating the formation of new neurons in the hippocampus via the serotonin receptor.
The study was conducted by Drs. Alexander Neumeister and Wayne Drevets and colleagues, of the U.S. National Institute of Mental Health (NIMH, Bethesda, MD, USA).