Cannabis receptor

Carpenter, Siri. The Changing Face of Marijuana Research. Monitor on Psychology, June 2001, pp. 40-42. Some people consider marijuana to be highly addictive and a gateway to harder drugs, while others believe it to be a social drug no more harmful than alcohol. Between these two positions lies the reality that marijuana affects individuals differently, as shown by variation in withdrawal symptoms. The identification of cannabis receptors in the brain has led to the realization that some marijuana users may be motivated to continue use in order to avoid withdrawal symptoms. However, about 40 percent of users seem not to experience drug dependence or withdrawal symptoms. Treatment plans need to take these different responses into account. 

Hopfer CJ, Young SE, Purcell S et al (2006) Cannabis receptor haplotype associated with fewer cannabis dependence symptoms in adolescents. Am J Med Genet B Neuropsychiatr Genet 141B 895-901... 

Cannabinoid receptor Cannabis sativa Canna indica Canned foods... 

There are some specific differences between the cubic and extended ternary complex models in terms of predictions of system and drug behavior. The first is that the receptor, either ligand bound or not bound, can form a complex with the G-protein and that this complex need not signal (i.e., [ARiG] and [RjG]). Under these circumstances an inverse agonist (one that stabilizes the inactive state of the receptor) theoretically can form inactive ternary complexes and thus sequester G-proteins away from signaling pathways. There is evidence that this can occur with cannabi-noid receptor [26]. The cubic ternary complex model also... 

The two G-protein-coupled receptors for Cannabis psychotropic component, A9-tetrahydrocannabinol... 

Group of compounds which naturally occur in the hemp plant, Cannabis saiiva. Most of them are unsoluble in water. The most abundant cannabinoids are A9--tetrahydrocannabinol (THC), its precursor cannabidiol and cannabinol, which is formed spontaneously from THC. Cannabinoids exert their effects through G-protein coupled cannabinoid receptors (CBi/CB2). 

Dronabinol (tetrahydrocannabinol), the active principle from cannabis and synthetic cannabinoids, nabilone and levonantradol are effective in treating nausea and vomiting in cancer chemotherapy. The mode of action is unclear but appears to involve cannabinoid CBi receptors. Cannabinoids have been shown to reduce acetylcholine release in the cortex and hippocampus, and have been suggested to inhibit medullary activity by a cortical action. Inhibition of prostaglandin synthesis and release of endorphins may also be involved in the antiemetic effect. A review of trials of dronabinol, nabilone or levonantradol concluded that while the cannabinoids were superior to placebo or dopamine receptor antagonists in controlling emesis... 

Endocannabinoids. Figure 1 Chemical structures of the two most studied endocannabinoids, anandamide and 2-arachidonoylglycerol, of Cannabis sativa psychoactive principle, A9-tetrahydrocannabinol, and of the CB-i receptor antagonist/inverse agonist, rimonabant. 

Based on the role of endocannabinoids and cannabinoid receptors in several pathological conditions, the pharmacological manipulation of their levels or action is being developed as a therapeutic strategy. Enhancement of endocannabinoid signalling when this plays uniquely a protective role can be effected in a safer way using (i) cannabis extracts in which the presence of non-psychotropic cannabinoids with therapeutic activity per... 

Research on CBl knockout mice demonstrated the pivotal role of CBl receptors in cannabis dependence knockout mice have been shown not to self-administer cannabinoids (Ledent et al. 1999) and also to fail to exhibit symptoms ofSRl417l6A-precipitated withdrawal (Ledent et al. 1999 Lichtman et al. 2001). Although the research summarized earlier is consistent in reporting the occurrence of a variety of withdrawal symptoms following cessation of exposure to cannabinoids (which were injected), precipitated withdrawal in mice following chronic exposure to marijuana smoke was more recently reported (Lichtman and Martin 2002). 

Teesson M, Lynskey M, Manor B, et al The psychometric properties of BSM-IV cannabis use disorders. Brug Alcohol Bepend 68 235—262, 2002 Tsou K, Patrick SL, Walker JM. Physical withdrawal in rats tolerant to delta 9-tetrahydrocannabinol precipitated by a cannabinoid receptor antagonist. Eur J Pharmacol 280 R13-R15, 1995... 

Before the discovery of specific cannabinoid receptors, the term cannabinoid was used to describe the biologically active constituents of the Cannabis sativa plant, including A -THC (67), cannabidiol (68) and their analogues and derivatives, many of which have characteristic pharmacological effects. 

A -THC, the main psychoactive component of cannabis, is a moderately potent partial agonist of the CBi and CB2 receptors, while cannabidiol has little affinity for either receptor (Table 6.7). The term classical cannabinoids is used to describe cannabinoid receptor modulators structurally related to (67), which have a tricyclic dibenzopyran core. While several other structural types of cannabinoid receptor modulators have been discovered in recent years, the classical cannabinoids are still by far the most extensively studied group in terms of SAR and pharmacology. 

Cannabinoid receptors are expressed throughout the cerebral cortex and the hippocampus, and a subpopulation of these cells appear to show an unusually high level of activity. It is possible that cells in these areas modulate the sensory effects of cannabis, particularly the effects on perception, task performance and memory. In addition, the anticonvulsant properties of cannabis are believed to be mediated here. Parts of the hypothalamus show high levels of receptor sites for cannabinoids this may be related to hypothermia effects. High levels in the cerebellum may be related to mediating the property of cannabinoids that produces the reduction in ataxic (muscle co-ordination) symptoms in certain disorders (Herkenham et al., 1991). 

Pertwee RG (1998). Advances in cannabinoid receptor pharmacology. In D Brown (ed.), Cannabis (pp. 125-174). Harwood Academic Publishers, Amsterdam. 

Marijuana and hashish are derivatives of the cannabis sativa plant 919 Cannabinoid effects in the CNS are mediated by the CB1 receptor 919 Endocannabinoids are endogenous ligands for the CB1 receptor 919 Endocannabinoids serve as retrograde messengers 920 There are many similarities between endogenous opioid and cannabinoid systems 921... 

Marijuana and hashish are derivatives of the cannabis sativa plant. Although cannabinoids have been used for centuries for recreational and therapeutic purposes, dramatic advances in cannabinoid neurobiology have occurred since 1990 [34-37]. This is attributable to the cloning of cannabinoid receptors and the discovery of endogenous cannabinoids, termed endocannabinoids. 

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