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Cancer presents itself as one of the biggest challenges in public health worldwide due to its high prevalence and mortality rates. It is a very aggressive disease with innumerous evasion mechanisms to treatment, resulting in many cancers still being a death sentence. Research across the globe concerning this disease has made important progress for its treatment, although many gaps and challenges remain. In this context, cannabinoids, chemical substances found in the Cannabis plant, seem to demonstrate desirable therapeutic effects in varying types of cancer, shown in in vitro, in vivo, and some few case studies. Thus, the current research constitutes itself as a systematic review of the literature to gather, evaluate and measure the state of the art and application of Cannabis as a therapeutic option and adjuvant in the treatment of cancer. [ABSTRACT FROM AUTHOR]

Introduction: Cannabidiol (CBD) has become a promising bioactive for the next decades after the recent recognition of the medical potential of Cannabis derivatives by United Nations member countries, as it has no psychotropic potential as your isomer Δ9-tetrahydrocannabinol (Δ9-THC). The differentiation of these isomers has been studied for decades. Recent studies demonstrate that even with more subtle chemical characteristics, such as those of the CBD enantiomers, there are considerable bioactive differences. However, there are still not many studies on their chemical structures. Aim: This work aims to present experimental data obtained by Nuclear Magnetic Resonance (NMR) to better elucidate the three-dimensional structure of this enantiomeric bioactive. Materials and methods: For this, a sample of nonsynthetic high purity CBD was subjected to different one-dimensional (1D-NMR) and two-dimensional (2D-NMR) analyses related to the hydrogen (¹H) and carbon (13C) nuclei. Results and discussion: The 1D-NMR techniques used are sufficient to distinguish the CBD and Δ9-THC isomers, but not to identify the enantiomeric characteristics of the non-synthetic CBD. Conclusions: It is concluded that the two-dimensional homonuclear (¹H,¹H) and heteronuclear (1H,13C) techniques analyzed are suitable to help distinguish CBD enantiomers. [ABSTRACT FROM AUTHOR]

Introduction: Considered the first plant cultivated by man, Cannabis has historical records dating from 4000 B.C. It is believed to have originated in the temperate and tropical regions of Asia. Over time, the plant has stood out due to its high therapeutic potential for various pathologies, thus leading to a need for health professionals to understand its applications, focusing on the quality of care offered to the patient that makes use of its phytotherapics, being they the base of the main cannabinoids of the plant, Cannabidiol (CBD) and Tetrahydrocannabinol (THC). Objective: To review the scientific literature on the knowledge of nursing professionals related to the care of patients who use cannabinoid-based drug therapy. Methods: Integrative literature review, seeking to gather results and develop an explanation on the topic, with the keywords "Cannabis", "Marijuana"or "CBD/THC", combinedwith "Nursing"or "Nurse". Results: The final sample consisted of 13 articles, divided into two topics, the first related to the knowledge of nursing professionals and the second, presenting the professionals' view on the use of Cannabis as a medicinal treatment. Conclusion: There was an agreement between studies reviewed on both topics, mainly related to the need to expand the specific knowledge of professionals about Cannabis for therapeutic purposes. Provide an improvement in the quality of teaching related to medical Cannabis, as well as complementary courses for trained professionals, seeking to ensure an improvement in the quality of care for patients. [ABSTRACT FROM AUTHOR]

Introdução: Considerada a segunda doença neurodegenerativa de maior prevalência no mundo, a Doença de Parkinson (DP) carece de tratamentos neuroprotetores eficazes. Os fármacos disponíveis atuam principalmente no alívio de sintomas motores, com pouco ou nenhum efeito sobre os sintomas não-motores. Evidências apontam que o sistema endocanabinoide modula indiretamente a neurotransmissão dopaminérgica, tornando-se um alvo farmacológico potencial para a DP. Objetivo: O presente trabalho avaliou os efeitos do tratamento com beta-cariofileno (BCP), um agonista dos receptores canabinoides do tipo 2, nas alterações comportamentais não-motoras causadas por um modelo de DP induzido por 6-hidroxidopamina (6-OHDA) em ratos. Método: Foram utilizados 45 ratos Wistar machos adultos (250-350 g), divididos em 4 grupos: SHAM, BCP (100 mg/Kg/dia; intraperitoneal), 6-OHDA (10 Îg/hem) e 6-OHDA+BCP. A 6-OHDA foi administrada bilateralmente no dia 0, através de cirurgia estereotáxica, no estriado dorsolateral (AP, +0,2 mm; ML, ±3.5 mm; DV, â'4.8 mm a partir do bregma) dos animais. Animais dos grupos SHAM e BCP receberam apenas veículo (0.01% de metabissulfito de sódio em salina). A partir do dia 1, os animais foram tratados com BCP diariamente e submetidos a avaliação comportamental para mensuração de parâmetros olfatórios (dia 3), mnemônicos (dias 5 a 7) e comportamento tipo-anedônico (dia 8). Para avaliação da função olfatória, foi utilizado o teste de discriminação olfativa (TDO); as memórias de curto prazo (MCD) e de longo prazo (MLD) foram avaliadas no teste de reconhecimento de objetos (TRO) e o comportamento tipo-anedônico foi avaliado pelo teste do esguicho. Resultados: A análise de variância (ANOVA) de duas vias demonstrou um efeito principal da 6-OHDA no tempo de exploração do compartimento familiar (p=0,034), indicando um déficit na capacidade de discriminar odores nos animais que receberam a neurotoxina. Este prejuízo olfatório foi atenuado pelo tratamento diário com BCP. Em relação ao TRO, não houve diferença no tempo de exploração dos objetos na sessão de treinamento, demonstrando que os animais não tiveram preferência por algum deles. Por outro lado, a análise de teste t mostrou que o grupo 6-OHDA não apresentou diferença estatística entre o índice de reconhecimento apresentado e o valor teórico de 50% nas sessões de MCD (p=0.953) e MLD (p=0.548), indicando prejuízo cognitivo. De importância, o tratamento diário com BCP foi capaz de reverter ambos os comprometimentos cognitivos induzidos pela 6-OHDA (MCD: p=0.003 e MLD: p=0.0004 vs. o valor teórico de 50%). Quanto ao comportamento tipo-anedônico, a ANOVA de duas vias mostrou um efeito da interação entre as variáveis 6-OHDA e BCP (p=0.030). De fato, o teste de Tukey indicou que os animais do grupo 6-OHDA apresentaram uma redução no tempo total de autolimpeza quando comparados ao grupo SHAM (p=0.047), inferindo um comportamento do tipo-anedônico, que foi revertido pelo tratamento diário com BCP (p=0,0001). Conclusão: Ao todo, os resultados obtidos demonstram que a administração diária de BCP atenuou e/ou reverteu os prejuízos olfatórios, cognitivos e tipo-anedônico causados pelo modelo de DP induzido por 6-OHDA em ratos. Portanto, nossos dados sugerem um possível papel neuroprotetor do BCP no tratamento dos sintomas não-motores associados à DP. [ABSTRACT FROM AUTHOR]

Backgroung: Cannabis sativa has a fascinating history and has been used by mankind for millennia. Many societies such as Greek, Roman, Chinese, African, Indian and Arabic take advantage of the plant's qualities, which are consumed as food, medicine, fuel, fibers or tobacco. The first reference found related to the therapeutic use of the plant data from 2700 B.C. and is present in the pharmacopoeia of the Chinese Emperor Shen-Nung, where this plant was recommended in the treatment of malaria, rheumatic pain, in irregular and painful menstrual cycles. The book "De Matéria Médica", written by the doctor Pedânio Dioscórides considered thefounder of pharmacology, exposes Cannabis as one of the natural substances that can relieve inflammatory pain. In Brazil, African slaves brought a cannabis during the colonial period, around 1549. Then, its use spread quickly among black slaves and Indians, who started to cultivate it. Once the plant was popularized among French intellectuals and English doctors in the Indian imperial army, it started to be considered in our country as an excellent medicine for men, until it was suppressed by the police authorities in the 1930s. Only 60 years later important findings were highlighted around Cannabis with the System Endocannabinoid and its receptors, neurotransmitters such as anandamide and 2-AG, revolutionizing the understanding of molecular signaling that modulates pain and analgesia, inflammation, appetite, gastrointestinal motility and sleep cycles, immune cell activity and hormones among others. We are in front of a huge revolution in the therapeutic area, in which phytocabinoids represent one of the great therapeutic options of the century. We need a widespread disclosure that CBD is not marijuana and that its use for recreational purpose has nothing to do with the use of medical cannabis. Scientific research is seriously committed to the use of the substance in various pathologies. The role of information is absolute, being the main tool to clarify a society. [ABSTRACT FROM AUTHOR]

The Cannabis sativa is the most common plant of the genus Cannabis being cultivated in almost all the world. Among the cannabinoids, the most important are the Δ9 - THC and the CBD which has won prominence due anticonvulsant, anti - inflammatory effects, among others. Although Δ9 -THC induces a number of undesirable effects, it also exhibits therapeutic properties, such as anti-emetic and analgesic activities. Therefore, this study aims to approach the possibilities of therapeutic use of cannabinoids. To do this, a search was performed in the PubMed database, selecting articles published after 2015. Studies are found in which Δ9 - THC demonstrated positive results for the treatment of chronic pain, neuropathic pain, NCCP, PTSD and anorexia nervosa. CBD, on the other hand, has shown therapeutic potential for seizures. The oromucosal spray THC: CBD has been shown to be effective in peripheral neuropathic pain, MS and ADHD. Finally, THCV, an antagonist of CB1 receptors, has been shown to act to suppress appetite and reduce glycemia in type 2 diabetics. The studies found allow us to conclude that the Δ9 - THC and CBD have several pharmacological properties, being an alternative to the use of other drugs. [ABSTRACT FROM AUTHOR]

Chronic Historical records report the use of cannabis for pain treatments since around 3000 B.C. However, only in the 1960’s, the active components of Cannabis (CBD, THC, among others 100) were described by scientists and, finally, in 1980, the first Cannabinoid endogenous, anandamide (AEA), was identified, which reiterated the significances of the cannabinoid receptor and its endogenous binders in the control of a wide variety of biological activities. The Sanskrit name "Anandamide" ("Ananda" means bliss), is given to N-arachidonoylethanolamine, for its cannabinomimetic effects. Subsequently, another endogenous cannabinoid compound known as 2-Arachidonoylglycerol (2-AG) was identified. Considering that these compounds are endogenous and cannabinomimetics, acting on cannabinoid receptors, they were termed as endocannabinoids (EC), which together with enzymes of synthesis and degradation, compose the endocannabinoid system (SEC). Nowadays, among the therapeutic options aimed at the best quality of life of patients, the use of cannabinoids, as adjuvant in the treatment, has gained great prominence in scientific studies that evidence its therapeutic potential in pain and chronic pain. PURPOSE: This article aims to review the compassionate use of cannabinoids in the control of chronic pain. METHODS: Bibliographic review on the use of cannabinoids in the treatment of chronic pain. We’ve selected 50 articles: reviews, double-blind randomized controlled clinical trials, cohorts, studies with patients and rats, book chapters and governmental and international released documents (FDA, WHO), in the main databases available (PubMed, Google Scholar). LITERATURE REVIEW and DISCUSSION: The positive relationships between the use of cannabinoids and the control of symptoms observed in patients in treatment of chronic diseases and in other forms of symptoms were verified in controlled studies and laboratory cohorts. Tolerance and side effects of cannabinoids are considerably lower when compared to opioids and no deaths from cannabis overdose were reported. CONCLUSION: This current review has confirmed the beneficial and less deleterious effect of cannabinoids in adjuvant pain and inflammation treatments, among other symptoms related to the treatment of various pathologies that are associated with chronic pain. Evidence based plant medications should be widely encouraged to be researched and developed due to its low cost of production and vast availability. The pain control of the adjuvant therapy with cannabinoids leads to an improvement in the quality of life of patients, caretakers and their families. It is necessary governmental, private and society motivation for the development of research and innovations that benefit and focus on the patient and improve their quality of life while looking at the patient as a complete and integral human being as in the definitions of Health by World Health Associations (WHO). [ABSTRACT FROM AUTHOR]

Pain in the cancer patient is an important clinical manifestation that results in low life expectancy and poor prognosis. Pain may be related to tumor type, invasion of adjacent tissues, metastasis, and diagnostic and therapeutic procedures with variable response to analgesic therapy. Many studies have called attention due to their potential therapeutic effect in the modulation of pain and inflammation. Cannabinoid derivatives are chemical compounds obtained from Cannabis that act on specific receptors.Several commercial products have already been approved in Europe and the USA for use in human patients. The present study aimed to review articles on the use of cannabinoids in the control of pain contributing to the well-being and quality of life in cancer patients undergoing palliative care. Although, there are few reports in the veterinary medical literature on the use of cannabinoids in the control of pain in dogs, it is believed that such patients can benefit from this therapeutic modality. [ABSTRACT FROM AUTHOR]

A Cannabis sativa, popularmente conhecido como maconha, é considerada a droga ilícita mais popular e consumida no mundo. Arbusto do gênero Cannabis, possui mais de quatrocentas substâncias em sua composição, sendo as principais o THC (tetrahidrocanabinol) e CBD (canabidiol), capazes de ligar-se aos receptores endocanabinóides do organismo humano, alterando a resposta dada pelo sistema nervoso central e periférico, não elucidados por completo, por se tratar de substâncias ilegal no Brasil, o qual dificulta os estudos científicos. Durante a década de 70, inúmeros estudos foram desenvolvidos após a descoberta do sistema endocanabinóide, visto que deveriam haver ligantes naturais para os sítios de ação no qual o princípio ativo da Cannabis tem afinidade, sendo, principalmente, eficaz em tratamentos neurológicos. [ABSTRACT FROM AUTHOR]

Objective: To understand the process of regulating the use of marijuana for medicinal purposes. Materials and Methods: Hermeneutical method with qualitative approach, using the interview technique, applied to fifteen experts in October 2015. Interpretation was performed from categorical system and support of Atlas.ti bar program. Results: The debate on the regulation of marijuana for therapeutic purposes continuous sweeping the globe, particularly in relation to health benefits. With the use of some cannabinoids there is some evidence, but experts consulted recognize that they are not sufficient in these cases: further investigation is recommended. The interviewed experts from different disciplines support the arguments that the ban imposed over marijuana little has achieved and that public health approaches bring a non-repressive scientific openness to the situation, placing the debate on the potential benefits it can bring for the treatment of some diseases. These regulatory processes must consider control over the production, manufacture, export, distribution, sale and use of cannabis for medical and research purposes, other than the legalization of recreational use process. Conclusion: For the Colombian case, the regulation of cannabis for medicinal purposes, until a few months ago was just an argument with radicalized positions for and against. Today it is reality as it was approved by decree on which progress in terms of legislation is being done, but with little debate, research and information to the population. [ABSTRACT FROM AUTHOR]

This article reviews the effectiveness of cannabinoid therapy in the treatment of orofacial pain. Cannabinoid therapy aims to stimulate the activity of the endocannabinoid system (ECS), which is involved in physiological and pathological functions such as immunomodulation, inflammation, and analgesia. The review included 5 articles from clinical studies conducted in the last 5 years, which showed that cannabinoid therapy reduced orofacial allodynia and hyperalgesia in experimental animal models, with different responses according to gender. Furthermore, evidence shows that the ECS is involved in modulating pain signals from the dental pulp and in exercise-induced hypoalgesia. However, most studies are still in the laboratory spectrum, and further translational studies and clinical trials are needed to better investigate the treatment of orofacial pain with cannabinoid therapy. [Extracted from the article]

The Marijuana, hashish, charas, bhang and sinsemilia are some designation given to the Cannabis sativa, a bush Moraceae Family, with more 100 products identified from her resin glands. This products are called of cannabinoids. The two cannabinoids main are, the Δ9-tetrahydrocannabinol (Δ9-THC) and the cannabidiol (CBD). After this discovery another products were isolated, such as for example, the annandamida (N-arachidonoyl-ethanolamide, AEA), that make part endocannabinoids, in other words are cannabinoids that occur endogenously. For 4.000 before Christ already there was report of the use medical of Cannabis sativa and in the nowadays this plant come having very purpose, as by effects derive from Δ9-THC, like, euphoria, hallucinations, among others, as to use therapeutic, the which CBD is responsible. As the CBD as the Δ9-THC bind the receptors that are coupleds the G-protein, in the several organ, the receptors are denominated as CB1 e CB2. Moreover this two receptors the CBD bind the another kind of receptors as, TRPV, 5-HT1A, GPR55 e PPARγ, taking the several therapeutics effects. [ABSTRACT FROM AUTHOR]

Recent advances in knowledge about cannabinoid receptor function have renewed interest in the association between cannabis and psychosis. Converging lines of evidence suggest that cannabinoids can produce a full range of transient schizophrenia-like positive, negative and cognitive symptoms. Cannabinoids also produce some psychophysiological deficits also known to be present in schizophrenia. Also clear is that in individuals with an established psychotic disorder, cannabinoids can exacerbate symptoms, trigger relapse, and have negative consequences on the course of the illness. Increasing evidence suggests that early and heavy cannabis exposure may increase the risk of developing a psychotic disorder such as schizophrenia. The relationship between cannabis exposure and schizophrenia fulfills some, but not all, of the usual criteria for causality. However, most people who use cannabis do not develop schizophrenia, and many people diagnosed with schizophrenia have never used cannabis. Therefore, it is likely that cannabis exposure is a "component cause" that interacts with other factors to "cause" schizophrenia or other psychotic disorder, but is neither necessary nor sufficient to do so alone. In the absence of known causes of schizophrenia, however, and the implications for public health policy should such a link be established the role of component causes such as cannabinoid exposure should remain a focus of further study. Finally, further work is necessary to identify the factors that underlie individual vulnerability to cannabinoid-related psychosis and to elucidate the biological mechanisms underlying this risk. [ABSTRACT FROM AUTHOR]

Objective: The present review provides a brief introduction into the endocannabinoid system and discusses main strategies of pharmacological interventions. Method: We have reviewed the literature relating to the endocannabinoid system and its pharmacology; both original and review articles written in English were considered. Discussion: Cannabinoids are a group of compounds present in Cannabis Sativa (hemp), such as Δ9-tetrahydrocannabinol, and their synthetic analogues. Research on their pharmacological profile led to the discovery of the endocannabinoid system in the mammalian brain. This system comprises at least two G-protein coupled receptors, CB1 and CB2, their endogenous ligands (endocannabinoids; e.g. the fatty acid derivatives anandamide and 2-arachydonoyl glycerol), and the enzymes responsible for endocannabinoid synthesis and catabolism. Endocannabinoids represent a class of neuromessengers, which are synthesized on demand and released from post-synaptic neurons to restrain the release of classical neurotransmitters from pre-synaptic terminals. This retrograde signalling modulates a variety of brain functions, including anxiety, fear and mood, whereby activation of CB1 receptors was shown to exert anxiolytic- and antidepressant-like effects in preclinical studies. Conclusion: Animal experiments suggest that drugs promoting endocannabinoid action may represent a novel strategy for the treatment of depression and anxiety disorders. [ABSTRACT FROM AUTHOR]

Objective: To review the main advances related to the potential therapeutic use of cannabinoid compounds in psychiatry. Method. A search was performed in the online databases PubMed, ScieELO, and Lilacs for studies and literature reviews concerning therapeutic applications of cannabinoids in psychiatry, especially cannabidiol, rimonabant, Δ9-tetrahydrocannabinol, and their analogues. Results: Cannabidiol was found to have therapeutic potential with antipsychotic, anxiolytic, and antidepressant properties, in addition to being effective in other conditions. Δ9-tetrahydrocannabinol and its analogues were shown to have anxiolytic effects in the treatment of cannabis dependence and to function as an adjuvant in the treatment of schizophrenia, although additional studies are necessary to support this finding. Rimonabant was effective in the treatment of the subjective and physiological symptoms of cannabis intoxication and functioned as an adjuvant in the treatment of tobacco addiction. The potential to induce adverse reactions such as depression and anxiety restrained the clinical use of this CB1 antagonist. Conclusion: Cannabinoids may be of great therapeutic interest to psychiatry; however, further controlled trials are necessary to confirm the existing findings and to establish the safety of such compounds. [ABSTRACT FROM AUTHOR]

Objective: Evidence that cannabis use impairs cognitive function in humans has been accumulating in recent decades. The purpose of this overview is to update knowledge in this area with new findings from the most recent literature. Method: Literature searches were conducted using the Web of Science database up to February 2010. The terms searched were: "cannabi" or "marijuana", and "cogniti" or "memory" or "attention" or "executive function", and human studies were reviewed preferentially over the animal literature. Discussion: Cannabis use impairs memory, attention, inhibitory control, executive functions and decision making, both during the period of acute intoxication and beyond, persisting for hours, days, weeks or more after the last use of cannabis. Pharmacological challenge studies in humans are elucidating the nature and neural substrates of cognitive changes associated with various cannabinoids. Long-term or heavy cannabis use appears to result in longer-lasting cognitive abnormalities and possibly structural brain alterations. Greater adverse cognitive effects are associated with cannabis use commencing in early adolescence. Conclusion: The endogenous cannabinoid system is involved in regulatory neural mechanisms that modulate processes underlying a range of cognitive functions that are impaired by cannabis. Deficits in human users most likely therefore reflect neuroadaptations and altered functioning of the endogenous cannabinoid system. [ABSTRACT FROM AUTHOR]

Cannabinoids are natural or synthetic derivatives of marihuana which activate the CB1 and CB2 receptors in cell membranes. The normal ligands of these receptors, known as endocannabinoids, are lipids synthetized by our cells from arachidonic acid. Endocannabinoids produced by excited neurons retrogradely act upon axonal terminals that synapse on them, thus depressing release of excitatory or inhibitory neurotransmitters. Both (exo)cannabinoids and endocannabinoids attenuate pain sensitivity when they act upon the spinal cord. Here endocannabinoids normally mantain a certain level of "analgesia", and intrathecal administration of cannabinoids diminishes the transmission of pain messages in cases of inflammatory or neuropathic pain. The nonsteroidal anti-inflammatory drugs (NSAIDs) cause analgesia not only by inhibiting prostaglandin synthesis but also by inhibiting the degradation of endocannabinoids. [ABSTRACT FROM AUTHOR]

Objective: Experimental evidence has suggested that drugs that enhance cannabinoid type-1 (CB1) receptor activity may induce anxiolytic and antidepressant effects, whilst the opposite has been reported with antagonists. Thus, the objective of the present review is to discuss the potential psychiatric side-effects of CB1 receptor antagonists, such as rimonabant, which has been recently marketed in several countries for the treatment of smoking cessation, obesity and associated metabolic disorders. Method: Literature searches were performed in PubMed and SciELO databases up to February 2009. The terms searched were "obesity", "rimonabant", "cannabinoids", "unwanted effects", "diabetes", "smoking cessation" and "side-effects". Results: Clinical trials have revealed that rimonabant may promote weight loss in obese patients, although it may also induce symptoms of anxiety and depression. Discussion: Patients taking CB1 receptor antagonists should be carefully investigated for psychiatric side-effects. These drugs should not be prescribed for those already suffering from mental disorders. Nevertheless, the development of new compounds targeting the endocannabinoid system for the treatment of several conditions would be necessary and opportune. [ABSTRACT FROM AUTHOR]

Objective: The aim of this review is to describe the historical development of research on cannabidiol. Method: This review was carried out on reports drawn from Medline, Web of Science and SciELO. Discussion: After the elucidation of the chemical structure of cannabidiol in 1963, the initial studies showed that cannabidiol was unable to mimic the effects of Cannabis. In the 1970's the number of publications on cannabidiol reached a first peak, having the research focused mainly on the interaction with delta9-THC and its antiepileptic and sedative effects. The following two decades showed lower degree of interest, and the potential therapeutic properties of cannabidiol investigated were mainly the anxiolytic, antipsychotic and on motor diseases effects. The last five years have shown a remarkable increase in publications on cannabidiol mainly stimulated by the discovery of its anti-inflammatory, anti-oxidative and neuroprotective effects. These studies have suggested a wide range of possible therapeutic effects of cannabidiol on several conditions, including Parkinson's disease, Alzheimer's disease, cerebralischemia, diabetes, rheumatoid arthritis, other inflammatory diseases, nausea and cancer. Conclusion: In the last 45 years it has been possible to demonstrate that CBD has a wide range of pharmacological effects, many of which being of great therapeutic interest, but still waiting to be confirmed by clinical trials. [ABSTRACT FROM AUTHOR]

Settings: In a wide number of diseases, the presence of pain is a frequent complains, and nowadays pain is considered a public health problem. During the last decade diverse drugs for pain control had been introduced in the Mexican market. In the last five years studies which evaluate the usefulness of cannabinoids in pain management had been performed. For that reason the objective of this document is to evaluate the available medical literature regarding the usefulness of cannabinoids for pain management. Method: A search of available medical literature of studies which evaluate the usefulness of cannabinoids in pain management was made using the Pubmed/Medline database. Studies which documented that association were considered for analysis. Results: 208 documents were identified and only 41 met the criteria for possible analysis. From those studies only 24 documented the administration of a cannabinoid and the presence or absence of analgesia or pain relief. In the 24 documents 31 interventions were identified, and 23 interventions showed a favorable analgesia. Conclusions: These results suggest that the administration of cannabinoids for pain relief might have a possible therapeutic benefice. However, more studies which document this association are needed. [ABSTRACT FROM AUTHOR]

Action of GABA agonists and antagonists on memory. The θ rhythm. Muscimol may directly alter memory. Recently, a modified matching to position (MTP) paradigm was employed aimed at influencing the type of associations a rat may use to solve the task. The main behavioral manipulation was the application of a differential outcomes procedure (DOP). DOP implies correlating each event to be remembered with a different reward condition. This procedure will result in the development of specific reward expectations which will in turn increase and guide choice behavior. Such different reward expectations will not be present when the reward assignation used is either common or random (non-differential outcomes procedure, NOP). Intraventricular infusion of muscimol or CSF in rats carrying out a delayed MTP using either a MOP or an NOP protocol will affect both groups of rats, but the nature of the deficit will differ depending on the reinforcement contingencies. Rats trained in DOP will show general non-mnemonic damage independent of delay, i.e., performance will be affected at all delay intervals employed. On the contrary, rats trained in NOP will show delay-dependent damage. This appears to demonstrate that muscimol may also have untoward memory effects, which further indicates that activation of GABA receptors will affect a set of memory associations and functions. Difficulties experienced in the past regarding LTP induction at the level of the CA3-CA1 synapse using time-based spike presentation protocols have been disconcerting given the preeminence of these synapses as a model system for the study of synaptic plasticity. Results previously discussed in experiments using picrotoxin as a GABA inhibitor have suggested that such difficulties arise from the requirement that, for LTP to be induced, CA1 dendrites must be persistently and totally activated. Doublets used in this case represent a minimal burst, or level of post-synaptic stimulation for LTP induction that subsumes greater depolarizations. In vitro, synaptically induced bursts would correspond to regenerative electrical events in apical dendrites of pyramidal neurons. The same requirements for dendritic activation would be satisfied in vivo during the θ rhythm, which is present during active exploration. Therefore, GABA might serve as an engram modulator through the activation of the hippocampal θ rhythm. Effect of μ-opioid receptors on hippocampal memory activity. Hippocampal μ-opioid receptors (MOR) have been involved in the formation of memory associated with the abuse of opioid drugs. When chronically activated, and during programmed drug abstinence, MORs acutely modulate hippocampal synaptic plasticity. At the level of neuronal networks, MORs increase excitability of area CA1 by means of a disinhibition of pyramidal cells. The specific inhibitory interneuronal subtypes which become affected by activation of MORs are not known. Nevertheless, not all subtypes are inhibited and some subtypes preferentially express these receptors. In one study, the effect of activation of MORs on inhibitory patterns and propagation of excitatory activity in CA1 of rat hippocampus was investigated through cortical images created using voltage-sensitive dyes. MOR activation increased excitatory activity originated by the increased stimulating input to stratum oriens (i.e., Schäffer collateral and commissural [SCC] fibers, as well as the retrograde pathway), to stratum radiatum (i.e., SCC fibers) and to stratum lacunosum-moleculare (i.e., the perforant pathway and the thalamus). Increased excitatory activity was additionally facilitated by propagation through the neural network of area CA1. This was observed as a proportionally greater increment of amplitudes of excitatory activity in sites distant from the originally evoked activity.… [ABSTRACT FROM AUTHOR]