This report was recently a news item on this website, on which I made a post about how these cells have an effect on how much glucose or sugar needs to process information to our brain.
I have also read that we don't need too many carbs as our liver would supplement the lack of glucose unless you have a metabolic imbalance.
And how insulinoma or hyperinsulinaemia, having hypos, too much glucose, would effect how we think and the symptoms that occur such as anxiety, forgetfulness, lethargy and many , many more. And why depression in prevalent in T1.
Can someone find the news link?