The scans that show how caffeine takes over your brain and stops you getting tired

So with my other major post on caffeine good vs. bad here; ask your doctor.
I however am going to continue to drink coffee.

The scans that show how caffeine takes over your brain and stops you getting tired

Last paragraphs but read the whole thing at the link;
Several investigations show that moderate coffee consumption of 3 to 5 cups per day at mid-life is linked to a reduced risk of dementia in late life.'

The team found that the repeated intake of caffeine can occupy up to 50 per cent of the brain's A1 adenosine receptors, stopping these from receiving the sleep-promoting neurotransmitter they were intended to absorb.
It is likely that this blockage of a substantial amount of cerebral A1 adenosine receptors will result in adaptive changes and lead to chronic alterations of receptor express and availability, they said.
They determined that it was this structure that may offer some insight as to why coffee drinkers were at lesser risk of dementia.
'The present study provides evidence that typical caffeine doses result in a high A1 adenosine receptor occupancy and supports the view that the A1 adenosine receptor deserves broader attention in the context of neurodegenerative disorders,' said Dr Elmenhorst, lead author of the study published in The Journal of Nuclear Medicine.