Psychopharmacology
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Comparative Study
Sucrose consumption enhances the analgesic effects of cigarette smoking in male and female smokers.
Nicotine has analgesic actions in experimental animals and humans. Moreover, the analgesic properties of nicotine in experimental animals are increased by intake of sweet-tasting nutritive fluids. It is important to determine if the effects of diet on nicotine-induced analgesia are limited to experimental animals, or if these effects can be translated from the laboratory to clinical research situations. ⋯ These findings suggest that sucrose augments the analgesic properties of nicotine in humans, as well as in experimental animals, and suggest that diet could serve as an adjunct in the control of pain.
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Comparative Study
Effects of kappa-opioid receptor ligands on intracranial self-stimulation in rats.
Elevations in cAMP response element binding protein (CREB) function within the mesolimbic system of rats reduce cocaine reward in place conditioning studies and increase immobility in the forced swim test. Each of these behavioral adaptations can be interpreted as a depressive-like effect (i.e., anhedonia, despair) that may reflect reduced activity of brain reward systems. Furthermore, each effect appears due to increases in CREB-mediated expression of dynorphin, since each is attenuated by intracranial injections of the kappa-opioid receptor antagonist norBNI. ⋯ These data provide further evidence that stimulation of brain kappa-receptors may trigger certain depressive-like signs, and that kappa antagonists may have efficacy as antidepressants without having reward-related actions of their own.
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Comparative Study
Effects of three hypnotics on the sleep-wakefulness cycle in sleep-disturbed rats.
New sleep disturbance model in rats is useful for estimating the characteristics of some hypnotics. ⋯ The present insomnia model can be used as a sleep disturbance model for testing not only the sleep-inducing effects but also the sleep-maintaining effects including non-REM sleep and REM sleep of hypnotics.