Sustained concentration (also known as a sustained state of vigilance) will generate a different type of memory than a momentary startle, and these differences are linked to distinct signaling molecules in the brains of mice. Researchers at the RIKEN Center for Brain Science (CBS) used optogenetics to help visualize these dynamics in the living mouse brain, observing fast and slow molecular pathways that support memory function. These processes take place in brain cells called astrocytes, revealing another important way in which these cells help neurons.
Norepinephrine, also called noradrenaline, is a dual hormone and neurotransmitter that prepares the body for action. Previous research has shown that norepinephrine release is important for modifying synapses, the connections between neurons that form and consolidate memories. Astrocytes are the crucial mediators of these changes, and the researchers were interested in observing, in real time, what happens in these cells when mice are learning.