Illuminating the brain
There are about 100 billion neurons in the human brain, and each one belongs to elaborate networks that control our behavior, thoughts and emotions. A message from a single neuron can have far-reaching consequences in other brain areas, but those connections are difficult to decipher with current technology.To help map those networks, a team of researchers from MIT, Harvard, Boston University and Tufts University has now developed a way to selectively activate neurons in the awake mouse brain with light and then track the resulting activity in other brain regions, using a brain-scanning technique called functional magnetic resonance imaging (fMRI). By comparing this data to human fMRI brain scans, researchers could learn a great deal about the underlying brain circuits involved in disorders such as epilepsy, schizophrenia, autism and post-traumatic stress disorder. “In all of these cases, being able to link the human neuroimaging data to the actual circuit elements...