This is my thinking along the op's question.
Through my fight to get my diagnosis, I have had symptoms of really high glucose levels (hyperglycaemia), I have had my fair share of low glucose levels (hypoglycaemia), I have had high insulin (hyperinsulinaemia) and am now resident in ketosis, which is where I like to be! Because of my condition I have also been through the rollercoaster ride of fluctuating blood glucose levels.
Through the many, many papers on the subject of what the symptoms are especially concerning the brain and how these highs and lows affect your well being and how you can really suffer as the symptoms take over!
The symptoms of all the above do effect the brain in so many ways, otherwise how do you get symptoms?
Symptoms are the direct result of the brain's response to a change in any of the body's hormones, so many symptoms are similar wether high or low and up and down constantly.
So, yes! High glucose levels (hypoglycaemia) does effect your pathways and how you feel! Emotional response are natural defences against your hormones.
The chemistry of the balance in your blood varies, but too much of any of your hormones will trigger symptoms.
And what you eat will further disrupt the balance because the trigger of your brain, gut, insulin response is essentially important in keeping your blood glucose levels around normal if you have an metabolic condition.
I can assure you, if nitrogen narcosis is anything like my hypo hell, the symptoms are closely related.