According to the dynamic developmental behavioral theory proposed by Sagvolden et al, a hypofunctioning mesolimbic dopamine system is largely responsible for producing alterations in behavioral reinforcement and extinction, which, in turn, disrupts learning processes. (behavioralandbrainfunctions.biomedcentral.com)
Thinking about things you enjoy can be almost as effective as actually doing the activity which makes you happy: «the part of the brain responsible for feeling pleasure, the mesolimbic dopamine system, can be activated when merely thinking about something pleasurable, such as drinking one's favorite brand of beer or driving one's favorite type of sports car. (businessinsider.com)
And so the energy - balancing hypothalamus and the mesolimbic dopamine system have become very well connected. (sciencenews.org)