When blood sugar levels fall dangerously low, the brain doesn’t sit idle — it springs into action. A new study published in Cell Metabolism reveals that a specific group of brain cells, known as Galnt2 neurons, act as the body’s built-in safety switch against hypoglycemia, sending emergency signals to the liver to restore normal glucose levels.
Understanding this circuit gives us a new way to think about blood-sugar regulation — not just from the pancreas, but from the brain itself
the authors concluded
Researchers from the China Pharmaceutical University and collaborating institutes discovered that these neurons, located deep in the brain’s ventromedial hypothalamus (VMH), form part of a powerful brain-to-liver circuit. When the brain senses a lack of glucose — its main energy source — these neurons trigger a response that instructs the liver to produce and release sugar into the bloodstream.“It’s like a biological alarm system,” explained lead author Dr. Haiping Hao.
When the brain detects low sugar, it communicates directly with the liver to prevent the body from running out of fuel.”
The study also uncovered a two-phase process that helps the body fine-tune its reaction to fasting or energy shortage. In the first stage, the body quietly monitors falling sugar levels. In the second stage, when glucose drops below a critical threshold, the VMH neurons rapidly activate the liver’s glucose-production machinery.
Crucially, the researchers found that the Galnt2 gene acts as a molecular “brake” — adjusting how sensitive these neurons are to low blood sugar. In other words, Galnt2 helps set the “trigger point” for when the brain decides to intervene.
This discovery offers new insight into how the brain keeps blood sugar stable and could open doors to future diabetes therapies. By targeting this brain-liver circuit, scientists may be able to help people who struggle to sense or recover from hypoglycemia — a common and dangerous complication of diabetes treatment.
