How does a nerve cell adjust if O2 diffusion is interrupted?
If Oxygen diffusion is interrupted, there is a serious problem. Neurons inside of the brain slowly start to die, many other things like change in personality or the inability to process pain impulses occur if the brain is deprived of oxygen.If this is not fixed within 15 minutes it is impossible to survive.

The actual effects on the neurons are as follows:
Like in most cells the first solution to this kind of circumstance is anaerobic metabolism, the same happens in neurons but it does not last long and it is inefficient. As far as i'm concerned nerve conductance decreases in this kind of scenario and the receptors shrivel.

Well if the receptors are shriveling, they shouldn't be able to transfer impulses meaning that nerve conductance should stop.

This link to an article on the effects on the brain from oxygen deprivation.
https://www.livestrong.com/article/106179-effects-lack-oxygen-brain/