Desperately seeking sugar: Glial cells as hypoglycemia sensors

A life-saving response to hypoglycemia requires rapid sensing of decreases in glycemia and consequent brisk glucagon secretion. Preceding studies have shown that mice lacking glucose transporter type 2 (GLUT2) lose this response. In this issue of the JCI, Marty et al. report that glucose sensing and consequent pancreatic glucagon secretion are restored by re-expression of GLUT2 in glial but not neuronal cells (see the related article beginning on page 3545). A new, glucose-sensing role is ascribed to GLUT2-expressing glial cells.