Psychopharmacology
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Impulsive behavior is categorically differentiated between impulsive action, the inability to withhold from acting out a response, and impulsive choice, the greater preference for an immediate and smaller reward over a delayed but more advantageous reward. While the effects of N-methyl-D-aspartic acid (NMDA) receptor antagonists on impulsive action have been extensively characterized, there are very few and conflicting reports on the effects of this class of drugs on impulsive choice. ⋯ NMDA receptor uncompetitive, but not competitive, antagonists significantly increased impulsive choice, preferentially in low-impulsive rats. These findings demonstrate that the effects of NMDA receptor blockade on impulsive choice are not generalizable and depend on the specific mechanism of action of the antagonist used.
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Clinical Trial
Cognitive effects of intramuscular ketamine and oral triazolam in healthy volunteers.
Several studies have documented impairments in memory processes as a result of ketamine administration; however, few studies have compared the profile of cognitive effects of ketamine to other drugs. ⋯ Ketamine produces less cognitive impairment than triazolam at doses that produced greater subjective effects. Thus ketamine does not produce the underestimation of cognitive impairment typically seen with triazolam.
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Behavioral-economic demand curve analysis offers several useful measures of drug self-administration. Although generation of demand curves previously required multiple days, recent within-session procedures allow curve construction from a single 110-min cocaine self-administration session, making behavioral-economic analyses available to a broad range of self-administration experiments. However, a mathematical approach of curve fitting has not been reported for the within-session threshold procedure. ⋯ The exponential demand equation can be fit to single-session data using the threshold procedure for cocaine self-administration. Removing data points that occur during relatively unstable brain cocaine concentrations resulted in more accurate estimates of demand curve slope than graphical methods, permitting a more comprehensive analysis of drug self-administration via a behavioral-economic framework.
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Randomized Controlled Trial
Docosahexaenoic acid-concentrated fish oil supplementation in subjects with mild cognitive impairment (MCI): a 12-month randomised, double-blind, placebo-controlled trial.
Epidemiological studies have suggested a beneficial effect of fish oil supplementation in halting the initial progression of Alzheimer's disease. However, it remains unclear whether fish oil affects cognitive function in older people with mild cognitive impairment (MCI). ⋯ This study suggested the potential role of fish oil to improve memory function in MCI subjects. Studies with larger sample sizes, longer intervention periods, different fish oil dosages and genetic determinations should be investigated before definite recommendations can be made.
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An increasing number of herbal products has been introduced to treat anxiety and depression. Gelsemium elegans Benth (G. elegans) is a well-known herbal plant in Asia. Four major alkaloids (gelsemine, koumine, gelsevirine, and gelsenicine) have been isolated from G. elegans. Recently, interest has arisen to investigate the pharmaceutical potential of G. elegans alkaloids in the context of neuropsychopharmacology. ⋯ Gelsemine, koumine, and gelsevirine could be developed as the treatment of anxiety-related disorders in human patients. Their anxiolytic mechanism may be involved in the agonist action of glycine receptor in the brain.