Journal of psychopharmacology
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J. Psychopharmacol. (Oxford) · Feb 2013
Chronic treatment with selective I2-imidazoline receptor ligands decreases the content of pro-apoptotic markers in rat brain.
Selective I(2)-imidazoline receptor ligands induce neuroprotection through various molecular mechanisms including blockade of N-methyl-D-aspartate (NMDA) receptors. To investigate new neuroprotective mechanisms associated with I(2)-imidazoline receptors, the effects of selective (2-styryl-2-imidazoline (LSL 61122), 2-(2-benzofuranyl)-2-imidazoline (2-BFI), 2-(4,5-dihydroimidazol-2-yl) quinoline hydrochloride (BU-224)) and non-selective (idazoxan) I(2)-drugs on canonical apoptotic pathways were assessed in rat brain cortex. ⋯ Similar chronic treatments with LSL 60101 (the imidazole analogue of 2-BFI) and idazoxan (a mixed I(2)/α(2)-ligand) did not induce significant alterations of pro- or anti-apoptotic proteins. The disclosed anti-apoptotic mechanisms of selective I(2)-imidazoline drugs may work in concert with other molecular mechanisms of neuroprotection (e.g. blockade of NMDA receptors) that are engaged by I(2)-ligands.
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J. Psychopharmacol. (Oxford) · Jan 2013
Randomized Controlled TrialCannabidiol inhibits THC-elicited paranoid symptoms and hippocampal-dependent memory impairment.
Community-based studies suggest that cannabis products that are high in Δ⁹-tetrahydrocannabinol (THC) but low in cannabidiol (CBD) are particularly hazardous for mental health. Laboratory-based studies are ideal for clarifying this issue because THC and CBD can be administered in pure form, under controlled conditions. In a between-subjects design, we tested the hypothesis that pre-treatment with CBD inhibited THC-elicited psychosis and cognitive impairment. ⋯ In agreement, post-THC paranoia, as rated with the State Social Paranoia Scale (SSPS), was less in the CBD group compared with the placebo group (t=2.28, p<0.05). Episodic memory, indexed by scores on the Hopkins Verbal Learning Task-revised (HVLT-R), was poorer, relative to baseline, in the placebo pre-treated group (-10.6 ± 18.9%) compared with the CBD group (-0.4% ± 9.7 %) (t=2.39, p<0.05). These findings support the idea that high-THC/low-CBD cannabis products are associated with increased risks for mental health.
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J. Psychopharmacol. (Oxford) · Jan 2013
A flicker change blindness task employing eye tracking reveals an association with levels of craving not consumption.
We investigated attentional biases with a flicker paradigm, examining the proportion of alcohol relative to neutral changes detected. Furthermore, we examined how measures of the participants initial orienting of attention and of their maintained attention relate to levels of alcohol consumption and subjective craving in social drinkers. The eye movements of 58 participants (24 male) were monitored whilst they completed a flicker-induced change blindness task using both simple stimuli and real world scenes, with both an alcohol and neutral change competing for detection. ⋯ Thus we conclude that processing biases in the orienting of attention to alcohol related stimuli were demonstrated in higher craving compared to lower craving social users in real world scenes. However, this was not related to the level of consumption as would be expected. These results highlight various methodological and conceptual issues to be considered in future research.
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Many patients with psychiatric disorders do not obtain remission from available pharmacological and psychotherapeutic treatments. Recent studies have demonstrated that there is a role for the rational use of 'combination therapy' when treating patients with serious and treatment-resistant mental illnesses. ⋯ When using combination therapy, clinicians should consider: (a) pharmadynamic redundancy; (b) pharmacodynamic interactions; (c) pharmacokinetic interactions; and (d) avoid inadequate dosing of medications. Clinicians should also (e) regularly reassess the need for and benefit of continued combination therapy.
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J. Psychopharmacol. (Oxford) · Oct 2012
Δ⁹Tetrahydrocannabinol impairs visuo-spatial associative learning and spatial working memory in rhesus macaques.
Cannabis remains the most commonly abused illicit drug and is rapidly expanding in quasi-licit use in some jurisdictions under medical marijuana laws. Effects of the psychoactive constituent Δ⁹tetrahydrocannabinol (Δ⁹THC) on cognitive function remain of pressing concern. Prior studies in monkeys have not shown consistent evidence of memory-specific effects of Δ⁹THC on recognition tasks, and it remains unclear to what extent Δ⁹THC causes sedative versus specific cognitive effects. ⋯ It is concluded that Δ⁹THC disrupts cognition in a way that is consistent with a direct effect on memory. There was evidence for interference with spatial working memory, visuo-spatial associative memory and incremental learning in the latter task. These results and the lack of specific effect of Δ⁹THC in prior visual recognition studies imply a sensitivity of spatial memory processing and/or working memory to endocannabinoid perturbation.