It is neurochemically diverse (e.g., [144]), with glucocorticoid, insulin, leptin, ghrelin, and incretin receptors, which in normal operation are neuroprotective, but when dysregulated, as with chronic stress (e.g., PTSD and AN, with excessive glucocorticoid exposure) or metabolic disturbances (e.g., insulin or leptin in obesity for example), can dispose to injury. Here, INS is linked to post-traumatic stress disorder.