Thanks for the link. It's informative to read about others' experience with hypos. I've found that my low threshold is 65 mg/dl. That's when my body start to produce symptoms and counter-regulatory events start.
While most of the body can use a range of fuels to generate energy, breaking down fat or muscle when the food supply is low, our gray matter is picky. “The brain is fundamentally dependent on a continuous supply of glucose,” says McNay. “The brain is unique in that respect—other tissues can use alternative fuel, like fatty acids. The brain can’t do that. It needs that specific sugar.”
It's my understanding that the brain can also run quite nicely on ketones in the absence of glucose. I only mention this because there is a myth in the diabetes professional ranks that says a person needs a minimum of 130 grams of carbohydrates per day to meet the needs of the brain. This is not true. Many people can maintain extended fasts without suffering brain-shut down. I like to fast for 24 hours once per week and if my basal rates are calibrated well, I don't go low. In fact, it's often reported by people when fasting that they feel an elevated sense of brain clarity. The body can also produce some glucose from protein, when needed.
This is an important topic. I appreciate the link.