The brain plays a major role in homeostatic processes ranging from control of body temperature and fat mass to blood pressure and volume. Tight regulation of the circulating glucose level is similarly crucial for survival, and since the brain relies almost exclusively on glucose as a fuel source, it seems counterintuitive to think that the brain does not also play an important role in glucose homeostasis. Based on overwhelming evidence supporting the endocrine pancreas as the primary controller of the blood glucose (BG) level, however, the notion of a key role for the brain was discounted decades ago.
Yet recent findings are beginning to chip away at the foundation of the prevailing, islet-centered view of glucose homeostasis. This perceptual shift is being driven not by evidence against a role for the endocrine pancreas in glucose homeostasis, but by evidence that the endocrine pancreas is part of a larger regulatory system, the activity of which is integrated with other critical homeostatic control systems governed by the brain.
