Long-Term Effects of Cannabis on Brain Structure Giovanni Battistella, Eleonora Fornari, Jean-Marie Annoni, Haithem Chtioui, Kim Dao, Marie Fabritius, Bernard Favrat, Jean-Frederic Mall, Philippe Maeder and Christian Giroud Neuropsychopharmacology, 2014, 39, 2041–2048. doi:10.1038/npp.2014.67 Abstract The dose-dependent toxicity of the main psychoactive component of cannabis in brain regions rich in cannabinoid CB1 receptors is well known in animal studies. However, research in humans does not show common findings across studies regarding the brain regions that are affected after long-term exposure to cannabis. In the present study, we investigate (using Voxel-based Morphometry) gray matter changes in a group of regular cannabis smokers in comparison with a group of [...]
Lire la suiteHippocampal Neurotoxicity of D9-Tetrahydrocannabinol Guy Chiu-Kai Chan, Thomas R. Hinds, Soren Impey, and Daniel R. Storm The Journal of Neuroscience, 1998, 18, (14), 5322–5332 Marijuana consumption elicits diverse physiological and psychological effects in humans, including memory loss. Here we report that D9-tetrahydrocannabinol (THC), the major psychoactive component of marijuana, is toxic for hippocampal neurons. Treatment of cultured neurons or hippocampal slices with THC caused shrinkage of neuronal cell bodies and nuclei as well as genomic DNA strand breaks, hallmarks of neuronal apoptosis. Neuron death induced by THC was inhibited by nonsteroidal anti-inflammatory drugs, including indomethacin and aspirin, as well as vitamin E and [...]
Lire la suiteCannabinoids, Neurogenesis and Antidepressant Drugs : Is there a Link ? Manoela Viar Fogaça, Ismael Galve-Roperh, Francisco Silveira Guimarães and Alline Cristina Campos Current Neuropharmacology, 2013, 11, 263-275 Abstract Similar to clinically used antidepressants, cannabinoids can also regulate anxiety and depressive symptoms. Although the mechanisms of these effects are not completely understood, recent evidence suggests that changes in endocannabinoid system could be involved in some actions of antidepressants. Chronic antidepressant treatment modifies the expression of CB1 receptors and endocannabinoid (EC) content in brain regions related to mood and anxiety control. Moreover, both antidepressant and cannabinoids activate mitogen-activated protein (MAP) kinase and phosphoinositide 3- kinase(PI3 [...]
Lire la suiteConsideration of Ayahuasca for the Treatment of Post-traumatic Stress Disorder Jessica L. NIELSON, & Julie D. MEGLER MAPS Bulletin Annual Report, Winter 2012, 29-31. THERE IS A GROWING AMOUNT OF RESEARCH on the development of PTSD and its various treatments. The fact that many people who su!er from PTSD struggle with the currently approved therapeutic options that are available to them suggests that we need to start exploring alternative strategies to treat this disorder.1 With the large number of veterans returning home from war that may have or will develop PTSD, we must have a diverse framework of therapy and integration in place [...]
Lire la suiteEffects of psilocybin on hippocampal neurogenesis and extinction of trace fear conditionning CATLOW B.J., SONG S., PAREDES D.A., KIRSTEIN C.L., SANCHEZ-RAMOS J. Experimental Brain Research, 2013, 228, 481-491. Doi : 10.1007/s00221-013-3579-0 Abstract Drugs that modulate serotonin (5-HT) synaptic concentrations impact neurogenesis and hippocampal (HPC)-dependent learning. The primary objective is to determine the extent to which psilocybin (PSOP) modulates neurogenesis and thereby affects acquisition and extinction of HPC-dependent trace fear conditioning. PSOP, the 5-HT2A agonist 25I-NBMeO and the 5-HT2A/C antagonist ketanserin were administered via an acute intraperitoneal injection to mice. Trace fear conditioning was measured as the amount of time spent immobile in the presence of the conditioned [...]
Lire la suiteImplications for psychedelic-assisted psychotherapy : a functional magnetic resonance imaging study with psilocybin R. L. Carhart-Harris, R. Leech, T. M. Williams, D. Erritzoe, N. Abbasi, T. Bargiotas, P. Hobden, D. J. Sharp, J. Evans, A. Feilding, R. G. Wise and D. J. Nutt British Journal of Psychiatry, 2012, 200, 238-244. Doi : 10.1192/bjp.bp.111.103309 Background Psilocybin is a classic psychedelic drug that has a history of use in psychotherapy. One of the rationales for its use was that it aids emotional insight by lowering psychological defences. Aims To test the hypothesis that psilocybin facilitates access to personal memories and emotions by comparing subjective and neural responses to positive [...]
Lire la suiteDose-related Effects of Salvinorin A in Humans : Dissociative, Hallucinogenic, and Memory Effects MacLEAN K.A., JOHNSON M.W., REISSIG C.J., PRISINZANO T.E., GRIFFITHS R.R. : Psychopharmacology (Berl), 2013, 226, (2), 381–392. doi: 10.1007/s00213-012-2912-9 Abstract Rationale—Salvinorin A is a kappa opioid agonist and the principal psychoactive constituent of the plant Salvia divinorum, which has increased in popularity as a recreational drug over the past decade. Few human studies have examined salvinorin A. Objective—This double-blind, placebo-controlled study evaluated the dose-related effects of inhaled salvinorin A in individuals with histories of hallucinogen use. Methods—Eight healthy hallucinogen-using adults inhaled up to 16 doses of salvinorin A (0.375 - 21 μg/kg) in ascending order. Physiological, behavioral, [...]
Lire la suiteRole of the Serotonin 5-HT2A Receptor in Learning John A. Harvey Learning & Memory, 2003, 355-362 www.learnmem.org http://www.learnmem.org/cgi/doi/10.1101/lm.60803. This study reviews the role of the serotonin 5-HT2A receptor in learning as measured by the acquisition of the rabbit’s classically conditioning nictitating membrane response, a component of the eyeblink response. Agonists at the 5-HT2A receptor including LSD (d-lysergic acid diethylamide) enhanced associative learning at doses that produce cognitive effects in humans. Some antagonists such as BOL (d-bromolysergic acid diethylamide), LY53,857, and ketanserin acted as neutral antagonists in that they had no effect on learning, whereas others (MDL11,939, ritanserin, and mianserin) acted as inverse agonists in that [...]
Lire la suitePsychological variables implied in the therapeutic effect of ayahuasca : a contextual approach. Alba Franquesa, Alberto Sainz-Cort, Sam Gandy, Joaquim Soler, Miguel Ángel Alcázar-Córcoles, José Carlos Bouso Psychiatry Research, 2017 PII: S0165-1781(17)31377-X DOI: 10.1016/j.psychres.2018.04.012 Abstract Ayahuasca is a psychedelic decoction originating from Amazonia. The ayahuasca-induced introspective experience has been shown to have potential benefits in the treatment of several pathologies, to protect mental health and to improve neuropsychological functions and creativity, and boost mindfulness. The underlying psychological processes related to the use of ayahuasca in a psychotherapeutic context are not yet well described in the scientific literature, but there is some evidence to suggest that psychological [...]
Lire la suiteCannabidiol regulation of emotion and emotional memory processing : relevance for treating anxiety-related and substance abuse disorders Jonathan L.C. Lee, Leandro J. Bertoglio, Francisco S. Guimarães and Carl W. Stevenson British Journal of Pharmacology, 2017, 174, 3242–3256 DOI : 10.1111/bph.13724 Abstract Learning to associate cues or contexts with potential threats or rewards is adaptive and enhances survival. Both aversive and appetitive memories are therefore powerful drivers of behaviour, but the inappropriate expression of conditioned responding to fear- and drug-related stimuli can develop into anxiety-related and substance abuse disorders respectively. These disorders are associated with abnormally persistent emotionalmemories and inadequate treatment, often leading to symptom relapse. [...]
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