Glucose homeostasis is tightly regulated by neural and hormonal signals. The pancreas secretes insulin and glucagon to control blood glucose levels [1][4]. Insulin secretion is stimulated by rising blood glucose levels as well as neural signals from the vagus nerve [2][3]. Insulin signals the liver, muscle and adipose tissue to take up glucose from the bloodstream. Glucagon secretion is stimulated by falling glucose levels and signals the liver to break down glycogen into glucose [1][5].

The brain, particularly the hypothalamus, also helps regulate glucose homeostasis. Glucose-sensing neurons in the hypothalamus monitor blood glucose levels and modulate pancreatic hormone secretion as well as feeding behavior [3][6]. For example, low glucose levels activate sympathetic output from the hypothalamus to inhibit insulin secretion from the pancreas [2][4]. The brain integrates neural and hormonal signals related to glucose homeostasis to maintain blood glucose within a narrow range [1][6]. Disruptions in this regulation can lead to hyperglycemia or hypoglycemia.