Fifty years ago the reward system would be called pleasure center or reward center. Scientific research and progressive trends in neuroscience have relatively soon resulted in understanding, that the reward can not be the matter of specified neuronal population or well-defined center. Instead of that, scientists started talking about so-called reward system, which include dopaminergic projection from area ventralis tegmenti Tsai (VTA) towards nucleus accumbens (NAC). Nucleus accumbens later become a kind of substitute for the previous pleasure center. Nowadays we know, that in this projection plays the role not only dopamine, but also endocannabinoids, endoopioids, neuropeptides and various monoaminergic influences. Reward system is therefore not only dopaminergic system. And it is not only the circuit between VTA and nucleus accumbens, because the reward is not only non-specific vague feeling of pleasure, but it has it s own contexts, specific types and reinforcers. Thus reward processing requires inter-connected areas of dopaminergic midbrain, striatum, thalamus, prefrontal cortex, amygdala and hippocampus. This article is an integrative attempt to map problems on the various definitions of reward circuitry and to link them with the problems of addiction, especially on the model of pathological gambling.

Key words: reward system – mesolimbic dopaminergic system – neurobiology of addiction – pathological gambling