As you start across the street, out of the corner of your eye, you spot something moving toward you. Instantly, your brain shifts its focus to assess the potential threat, which you quickly determine to be a slow-moving bicycle – not a car – which will pass behind you as you complete your crossing.
The brain’s ability to quickly focus on life-or-death, yes-or-no decisions, then immediately shift to detailed analytical processing, is believed to be the work of the thalamus, a small section of the midbrain through which most sensory inputs from the body flow. When cells in the thalamus detect something that requires urgent attention from the rest of the brain, they begin “bursting” – many cells firing off simultaneous signals to get the attention of the cortex. Once the threat passes, the cells quickly switch back to quieter activity.
Using optogenetics and other technology, researchers have for the first time precisely manipulated this bursting activity of the thalamus, tying it to the sense of touch. The work, done in animal models, was reported January 14th in the journal Cell Reports. The research is supported by the National Institutes of Health’s National Institute of Neurological Disorders and Stroke.