Astrocytes—star-shaped glial cells long cast mainly as support staff for neurons—appear to actively shape how fear memories are learned, recalled and weakened, according to a mouse study published in Nature. The work suggests these cells help sustain the neural activity patterns that underlie fear expression, a finding that researchers say could eventually inform new approaches to anxiety-related disorders.
A multi-institutional research team led by Andrew Holmes and Olena Bukalo of the National Institutes of Health’s Laboratory of Behavioral and Genomic Neuroscience, working with University of Arizona neuroscientist Lindsay Halladay, reports evidence that astrocytes in the amygdala help regulate fear memories in mice.
In experiments focused on the amygdala—a brain region central to fear processing—the researchers tracked astrocyte activity using fluorescent calcium sensors. Astrocyte activity increased during fear learning and during recall, and declined as fear responses were extinguished, according to a University of Arizona account of the work.
The team then tested whether changing astrocyte signaling could alter behavior. By experimentally strengthening or weakening astrocyte activity, the researchers were able to increase or reduce the strength of learned fear responses in mice, the report said.
Halladay described the results as evidence that astrocytes participate directly in the brain’s fear circuitry. “For the first time, we found that astrocytes encode and maintain neural fear signaling,” she said.
The study also links astrocyte activity to the stability of neuron population patterns associated with fear. When astrocyte signaling was disrupted, neurons were less able to form normal fear-related activity patterns, and communication across the broader fear-related circuit was impaired, the researchers reported.
The authors said the findings add to growing evidence that fear and memory processes are not driven by neurons alone. While the work was conducted in mice and does not by itself establish new treatments, the researchers argued that understanding how astrocytes influence fear expression and extinction could eventually help inform strategies for conditions marked by persistent or inappropriate fear, including anxiety disorders.
The study was published in Nature and is associated with DOI: 10.1038/s41586-025-10068-0.
