Mouse study suggests caution in interpreting functional MRI results
K. Roberts et al/BMC Anesthesiol. 2008/Open-I (CC BY 2.0)
A mainstay of many neuroscience labs, functional MRI relies on blood flow changes in the brain to serve as proxies for active nerve cells. But a new study on mice finds that neurons can be busy with no hint of blood-flow changes.
Many researchers assume that fMRI signals reflect neural activity, says study coauthor Patrick Drew, a neuroscientist at Penn State, “that when neural activity goes up, you should see increases in blood flow.” But recently, that cozy relationship has come under increasing scrutiny.
The results, published in the Aug. 13 Journal of Neuroscience, emphasize the need for caution when interpreting brain-scan results, says neuroscientist Shella Keilholz of Georgia Tech and Emory University School of Medicine in Atlanta.
Functional MRI detects tiny changes in the brain’s amount of oxygenated blood, which researchers often interpret as signs of neurons sending