Psychopharmacology
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Randomized Controlled Trial
Transdermal nicotine attenuates depression symptoms in nonsmokers: a double-blind, placebo-controlled trial.
Despite established links between nicotine dependence and depression, little research has examined the effects of nicotine on depression symptoms. ⋯ These findings suggest a role for nicotinic receptor systems in the pathophysiology of depression and that nicotinic compounds should be evaluated for treating depression symptoms.
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Randomized Controlled Trial
Dose effects of triazolam on brain activity during episodic memory encoding: a PET study.
Although it is well established that acute benzodiazepine administration impairs episodic memory encoding, little is known about the neuroanatomical substrates of this effect. ⋯ Results are consistent with behavioral evidence that benzodiazepines impair prefrontal control processes as well as contextual memory and episodic binding processes thought to be controlled by the medial temporal lobe. In addition to elucidating the brain mechanisms underlying these benzodiazepine-induced behavioral deficits, results of this study also help validate hypotheses generated in nonpharmacological neuroimaging studies regarding the processes controlled by these brain regions.
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Randomized Controlled Trial
Effects of midazolam on explicit vs implicit memory in a pediatric surgery setting.
Placebo-controlled studies show that midazolam impairs explicit memory in children undergoing surgery (Buffett-Jerrott et al., Psychopharmacology 168:377-386, 2003; Kain et al., Anesthesiology 93:676-684, 2000). A recent within-subjects study showed that midazolam impaired explicit memory while leaving implicit memory intact in a sample of older children undergoing painful medical procedures (Pringle et al., Health Psychol 22:263-269, 2003). ⋯ Overall, it appears that midazolam induces a dissociation between explicit and implicit memory in young children in the pediatric surgery setting. Theoretical and clinical implications of the findings are discussed along with directions for future research.
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Chlorpyrifos (CPF) is a common organophosphate (OP) insecticide that has been widely used in extensive agriculture as a pesticide. The primary mechanism of acute toxic action of OPs is inhibition of acetylcholinesterase (AChE). However, targets other than AChE have been proposed to contribute to the acute lethal action and side effects of short- or long-term exposure to these compounds. Bekkedal et al. (Sci Total Environ 274:119-123;2001) showed that chronic administration of the OP trimethylolpropane phosphate (TMPP) reduces the number of schedule-induced polydipsia (SIP) sessions necessary to induce asymptotic drinking level. ⋯ Taken together, our data confirm and extend the long-term behavioral effects of subcutaneous administration of CPF and point to a role for other systems that, besides AChE inhibition, contribute to the long-term neurotoxicity of CPF.
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3, 4-Methylenedioxymethamphetamine (MDMA or "ecstasy") is a popular drug of abuse known to result in depletions of the serotonin (5-HT) system. A number of studies have reported that ecstasy users differ from controls on a variety of measures of cognitive function. However, the literature is not consistent and many negative findings were also reported. One reason for such inconsistency might be interindividual variance in vulnerability to the deleterious effects of ecstasy due to a number of factors, both genetic and environmental. ⋯ The results are consistent with the hypothesis that cognitive impairment in ecstasy users may depend on genetic variation at the 5-HTTLPR.