Picture a star-shaped cell in the brain, stretching its spindly arms out to cradle the neurons around it. That’s an astrocyte, and for a long time, scientists thought its job was caretaking the brain, gluing together neurons, and maintaining neural circuits. But now, a new study reveals that these supposed support cells that are spread all over the brain are as important as neurons in fear memory.

“Astrocytes are interwoven among neurons in the brain, and it seemed unlikely they were there just for housekeeping. We wanted to understand what they’re actually doing—and how they’re shaping neural activity in the process,” said Lindsay Halladay, assistant professor at the University of Arizona Department of Neuroscience and one of the study’s senior authors.

Halladay’s lab collaborated with researchers from the National Institutes of Health for this multi-institutional study, led by Andrew Holmes and Olena Bukalo of the Laboratory of Behavioral and Genomic Neuroscience.