A single rat astrocyte is splayed on a specialized nanowire structure. In its native environment, the cell would envelop hundreds of thousands of synapses, enabling it to monitor and adjust neuronal signaling. Image Credit: Johns Hopkins University
Health USABrain Science Reveals Overlooked Cells May Help Control Mood and Behaviour
Scientists have discovered that astrocytes, once thought to merely support neurons, actively regulate brain activity and influence mental and emotional states.
“These findings show that understanding connections between neurons alone is not enough to explain how the brain works,” said Marc Freeman, Director of the Vollum Institute at Oregon Health & Science University in the United States.
Experiments in fruit flies, zebrafish, and mice have demonstrated that astrocytes modulate brain signalling by releasing molecules that fine-tune neural circuits and regulate behavioural shifts, including alertness, sleep patterns, and persistence during challenges. The findings, published in 2025, show astrocytes outnumber neurons in many brain regions and can influence millions of synapses, suggesting new avenues for understanding psychiatric disorders, sleep regulation and potential treatments for brain conditions that have resisted therapies for decades.
