The neurons of the mesolimbic dopamine system originate in the midbrain and extend axons towards the limbic system of the forebrain. These neurons are associated with the reward pathways and behaviour. Stimulation of rewarding pathways makes an individual “feel good.”
Intracranial self-stimulation is a phenomenon, in which animals learn to initiate a stimulating electric current in their brains. It occurs because the electric current stimulate the neural system that is involved in reward pathway.