First of all, I'm sorry if this question doesn't suit this subreddit, but I find difficult to find more information about this matter on google.

As I have seen so far, when you do an activity your brain has to work, it has to focus on how to do it and learn the solutions, and for that it uses hormones which are not limitless. The result is new conections between the neurons which strengthen during sleep.

If this is correct, is the work and learning limitted by the production of this hormone? And then, how long does it take to get it back to regular levels? I have read that a night of sleep is enought, but maybe it can be less, or more.