Alcohol abuse and substance abuse in general is related to the immediate reward the substance offers, as well as the reinforcement caused by the repeated substance use. The mesolimbic pathway is considered crucial for the reward procedure. This pathway starts from the ventricular area, which is an area rich in dopamine in the midbrain (the ventral tegmental area (VTA)) [1,22]. The stimulating addictive substances act directly on the metasynaptic dopamine receptors, whilst non-stimulating ones, such as alcohol, act via the mesolimbic pathway through various receptor systems. Alcohol acts on the mesolimbic pathway modifying neuronal stimulation by interacting with ion channels and ionic receptors, affecting polarisation [26]. Alcohol increases the sensitivity of 5-HT3 serotonin receptors and this seems to be implicated in alcohol abuse/dependency development. Chronic alcohol use does not influence just one neurotransmitter but almost all neurotransmitter systems [27,28]. These actions can be categorised as following:
