Psychopharmacology
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Randomized Controlled Trial Multicenter Study Comparative Study
Intramuscular aripiprazole for the treatment of acute agitation in patients with schizophrenia or schizoaffective disorder: a double-blind, placebo-controlled comparison with intramuscular haloperidol.
This double-blind, placebo-controlled study investigated the efficacy and safety of intramuscular (IM) aripiprazole and IM haloperidol for the treatment of acute agitation in patients with schizophrenia or schizoaffective disorder. ⋯ These results show that IM aripiprazole is an effective treatment, comparable to IM haloperidol, and well-tolerated for acute agitation in patients with schizophrenia.
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Converging evidences from animal and human studies suggest that addiction is associated with dopaminergic dysfunction in brain reward circuits. So far, it is unclear what aspects of addictive behaviors are related to a dopaminergic dysfunction. ⋯ Compared to placebo, the BCAA mixture increased prolactin levels and impaired IGT performance. BCAA administration interfered with a particular component process of decision-making related to attention to more recent events as compared to more distant events. There were no differences between placebo and BCAA conditions for other aspects of cognition. Our results suggest a direct link between a reduced dopaminergic activity and poor emotion-based decision-making characterized by shortsightedness, and thus difficulties resisting short-term reward, despite long-term negative consequences. These findings have implications for behavioral and pharmacological interventions targeting impaired emotion-based decision-making in addictive disorders.
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Clinical data support a correlation between smoking and the incidence and severity of some chronic pain conditions. However, the impact of nicotine on neuropathic pain has been largely ignored in the laboratory setting. ⋯ These findings demonstrate that chronic nicotine produces a stable, long-lasting, mechanical hypersensitivity that exacerbates mechanical sensitivity resulting from peripheral nerve injury. The mechanism of this may involve an increase in spinal neuronal activity and apoptosis.
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Comparative Study Clinical Trial
Comparison of pramipexole and amisulpride on alertness, autonomic and endocrine functions in healthy volunteers.
In a previous study in healthy volunteers, the anti-Parkinsonian drug pramipexole caused sedation and pupil dilatation, consistent with the stimulation of inhibitory D(2)/D(3) autoreceptors on the ventral tegmental area dopaminergic neurones. The sedation may be related to the removal of the dopaminergic excitation of the locus coeruleus (via the meso-coerulear pathway), whereas the pupil dilatation may be due to the removal of the dopaminergic excitation of the Edinger-Westphal nucleus (via a putative meso-pupillomotor pathway). ⋯ The opposite effects of pramipexole and amisulpride on alertness, pupillary function and pituitary hormone levels are consistent with their interactions with inhibitory D(2)/D(3) receptors on VTA neurones and in the tuberoinfundibular system.
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Comparative Study
Differential role of 5-HT1A and 5-HT1B receptors on the antinociceptive and antidepressant effect of tramadol in mice.
Tramadol, (1RS,2RS)-2-[(dimethylamine)-methyl]-1-(3-methoxyphenyl)-cyclohexanol hydrochloride, is an atypical analgesic which binds weakly to ì-opioid receptors and enhances the extra-neuronal concentration of noradrenaline and serotonin by interference with both the uptake and release mechanisms. ⋯ These findings suggest that 5-HT1A receptors modulate the analgesic and the antidepressant-like effects of tramadol in differing ways. The results suggest the involvement of the 5-HT1A autoreceptors from the raphe nuclei and spinal 5-HT1A receptors in the antinociceptive effect. In contrast, the 5-HT1A receptors located in the forebrain may be responsible for the blockade of the antidepressant-like effect of tramadol. 5-HT1B receptors seem not to modify these effects in the models investigated.