"People tend to immediately think of neurons when they think about how the brain works. But we're finding that astrocytes, what we used to think of as just secondary support cells, are also participating in how our brains regulate how much we eat."
It might come as a surprise to learn that the brain responds to training in much the same way as our muscles, even though most of us never think about it that way. Clear thinking, focus, creativity, and good judgment are built through challenge, when the brain is asked to stretch beyond routine rather than run on autopilot. That slight mental discomfort is often the sign that the brain is actually being trained, a lot like that good workout burn in your muscles.
Neuroscientists have a name for the brain network that fires up when you're not focused on an external task: the default mode network, or DMN. It's the constellation of regions - the medial prefrontal cortex, posterior cingulate cortex, and angular gyrus among them - that hums to life when you daydream, reflect on yourself, or think about other people's mental states.