#astrocytes

#astrocytes

"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."

She imagined colleagues thinking, "Oh, that's the weird one who works on astrocytes," says Goshen, whose laboratory is at the Hebrew University of Jerusalem. A lot of people were sceptical, she says. But not any more. A rush of studies from labs in many subfields are revealing just how important these cells are in shaping our behaviour, mood and memory. Long thought of as support cells, astrocytes are emerging as key players in health and disease.

Astrocytes - brain cells once thought of as supporting players to neurons - have a principal role in stabilizing memories for long-term recall. In mice, researchers found that Fos, a gene associated with cell activity, was highly expressed in the astrocytes of mice that re-entered cages they'd been conditioned to associate with fear. The team also found that highly-active astrocytes produce more receptors that respond to the neurotransmitter noradrenaline, which allows them to communicate with neurons.

Recall transiently destabilizes memories, which require re-stabilization to become long-lasting. Despite its importance in human cognition and neuropsychiatric disorders6,7, the mechanisms that specifically stabilize memories of critical experiences-those that are essential for survival and frequently marked by emotional salience and repetition-remain incompletely understood. Memory traces are linked to specialized neuronal ensembles (neuronal engrams), which include neuronal populations that become Fos+ during both initial and repeated experiences8.