If I overdose on caffiene, will it damage the part of the brain that lets me go to sleep?

Caffiene. Od on caffiene can cause seizues and heart attack or other causes.
Caffeine. Before it would affect your brain, caffeine overdose will affect her heart and blood pressure and this is the real issue with this drug. In general caffeine blocks Adenosine production in the brain but does not damage your sleep centers. Hope this helps.