Additionally, serotonin also seems to play a significant role in the regulation of alcohol consumption. The serotonin transporter (5-HTT) intercedes to the presynaptic serotonin reuptake and thus serotoninergic neurotransmission is concluded. The gene that codes the 5-HTT protein shows a polymorphism having two common allelic genes that are different in length, L (long) and S (short). Various conditions related to addiction such as tolerance, sensitivity, dependence and so on, are the results of a molecular and cellular adaptation which takes place in specific brain areas as a results of repeated exposure to alcohol [24,25]. The exact neurobiological changes at the pharmacological level all the above-named actions provoke, and how they are related to the compulsive substance-seeking phenomenon (craving) are unknown.
