Social Factors and Animal Models of Cannabis Use

Cannabis, or the dried leaves, stems, and seeds of the hemp plant Cannabis sativa, is the most widely used illicit drug in America. Typically smoked, vaporized or ingested orally, cannabis is used primarily for recreational purposes, though a few synthetic cannabinoids have been approved for medicinal treatments. Psychoactive cannabinoids, or the pharmacologically active compounds within cannabis, are responsible for producing the infamous "high" sensation, characterized by feelings of euphoria and relaxation, though can also provoke hallucinations, paranoia and anxiety. Cannabinoids act on G-protein coupled receptors in the brain, primarilyCB1 receptors, that typically decrease neural activity and modulate transmitter release. Compared to other drugs of abuse, cannabis use has minimal health risks and almost no potential for fatal overdose, though the trademark method of administration (smoking) has detrimental consequences. Chronic heavy use can also lead to changes in memory, cognitive deficits, psychosis and dependence. Up to 9% of users can develop a cannabis dependence, characterized by a characteristic withdrawal syndrome. The growing prevalence of cannabis use has spurred the development of animals models to research the neurobehavioral basis of cannabis use. Traditional animal models of drug abuse (i.e., conditioned place preference (CPP) and self-administration) have historically struggled to establish rewarding or reinforcing effects of individual cannabinoid molecules. Decades of research have been needed to reveal the appropriate dosage and conditions to promote reward and reinforcement in animal models. While the field has made great strides in elucidating the mechanisms involved in behavioral pharmacology cannabinoids, the social aspects of cannabis use remains underrepresented in animal models. Social interactions are vital to the initiation and continuation of cannabis use in humans, and this component has yet to be accurately captured in current animal models.