title: Behavioral pharmacology of cannabinoids with a focus on preclinical models for studying reinforcing and dependence-producing properties.
abstract: Cannabis preparations as recreational drugs are the most widely used illicit drugs in the world. Although cannabis derivatives produce clear subjective motivational responses in humans leading to drug-seeking behavior and in a specific proportion in repeated drug use, the reinforcing/rewarding attributes of these subjective effects are difficult to define in experimental animals. This led to the notion of cannabinoids being considered as "atypical" or "anomalous" drugs of abuse. To this end, our knowledge and understanding of the way cannabis and its main psychoactive constituent, Delta(9)-tetrahydrocannabinol (Delta(9)-THC), act in the central nervous system to exert their reinforcing/rewarding effects is far from complete. The aim of the present article is to review from a preclinical perspective the current status of what is known about the behavioral pharmacology of cannabinoids including the recently identified cannabinoid neurotransmission modifiers with a particular emphasis on their motivational/reinforcing and dependence-producing properties. We conclude that cannabinoids exhibit reinforcing/rewarding properties in experimental animals mostly under particular experimental conditions, which is not the case for other drugs of abuse, such as opiates, psychostimulants, alcohol and nicotine. The paper will discuss these findings critically and also point to open questions that should be addressed in the future in order to improve our understanding of these specific actions of cannabinoids that will also impact drug discovery and development efforts of related compounds as therapeutics in the clinic.
authors.affiliation: Laboratory of Behavioral Neuroscience, Department of Psychology, School of Social Sciences, University of Crete, Crete, Greece. panagis@psy.soc.uoc.gr
authors.forename: George
authors.initials: G
authors.lastname: Panagis
authors.forename: Styliani
authors.initials: S
authors.lastname: Vlachou
authors.forename: George G
authors.initials: GG
authors.lastname: Nomikos
mesh_terms: D000818:Animals; D001095:Arachidonic Acids / Q000494:pharmacology; D001921:Brain / Q000187:drug effects; D002186:Cannabinoids / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D003214:Conditioning, Classical / Q000187:drug effects; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D013759:Dronabinol / Q000494:pharmacology; D004334:Drug Administration Schedule; D004361:Drug Tolerance; D063388:Endocannabinoids; D006801:Humans; D008253:Macaca mulatta; D002189:Marijuana Abuse / Q000523:psychology*; D051379:Mice; D009042:Motivation; D053284:Polyunsaturated Alkamides / Q000494:pharmacology; D051381:Rats; D043884:Receptor, Cannabinoid, CB1 / Q000819:agonists; D012201:Reward; D012646:Self Administration; D013375:Substance Withdrawal Syndrome / Q000175:diagnosis; D009435:Synaptic Transmission / Q000187:drug effects
chemical_list: D001095:Arachidonic Acids; D002186:Cannabinoids; D063388:Endocannabinoids; D053284:Polyunsaturated Alkamides; D043884:Receptor, Cannabinoid, CB1; D013759:Dronabinol; C078814:anandamide