I've been doing a bit of armchair biology lately, and have been interested in the metabolic flexibility of neurons. My understanding is that, besides glucose, many neurons can metabolize lactic acid or ketones. However, some reports point out that some neurons can only metabolize glucose, without ever indicating which, or in what regions of the brain. (It may be that the following exert is suggesting that each individual neuron is using a mix of fuel sources. I have not been able to find much via the Google.)
From the linked book:
When changing slowly from a carbohydrate diet to an almost completely fat diet, a person's body adapts to use far more acetoacetic acid than usual, and in this instance, ketosis normally does not occur. For instance, the Inuit (Eskimos), who sometimes live almost entirely on a fat diet, do not develop ketosis. Undoubtdly, several factors, none of which is clear, enhance the rate of acetoacetic acid metabolism by the cells. After a few weeks, even the brain cells, which normally derive almost all of their energy from glucose, can derive 50 to 75 percent of their energy from fats.
Which neurons and regions of the brain can only burn glucose?