TY - JOUR T1 - Neurobiology of Addiction TT - نوروبیولوژی پاداش و اعتیاد JF - icss JO - icss VL - 4 IS - 1 UR - http://icssjournal.ir/article-1-432-en.html Y1 - 2002 SP - 1 EP - 5 N2 - Human as well as laboratory animals can become dependent on a variety of drugs of abuse. Such as alcohol and opiates. Nevertheless, the ability of drugs to create dependence is poorly underst6od. Some of drugs or stimulation of some parts of brain may cause reward which is a response to a stimulus which causes pleasure. It seems that serotonin in hypothalamus enkephalins and GABA in ventral tegmentum area and nucleus accumbens and noradrenaline (release of noradrenaline in hyppocampus from neuronal fibers that originate in locus ceruleus) involve in biology of rewards but dopaminergic system is the final common pathway. Drugs acting on reward mechanism induce pleasure which is named reinforcement. The reinforcing effect of drugs, reinforcing in the sense that they caused the drugs to be used repeatedly areamatter of interest. The reinforcement causes tolerance and dependence to drug abuse. Alcohol, cocaine, morphine and amphetamine have reinforcement properties. Animal models that, can be used to study drug dependence are based on conditioning such as: Self Administration, Self-Stimulation and Conditioned Place Preference (CPP). Jumping behavior is also a model of opioid dependency. M3 ER -