Converging lines of evidence suggest that oligomers of amyloid-β play a role in the cognitive impairment characteristic of Alzheimer's disease, but only three studies have provided experimental evidence of such impairment. To provide additional information about the effects of these oligomers on memory, the present study examined the memory of groups of rats exposed to ICV injections of the culture media (CM) of Chinese Hamster Ovary cells that were (7PA2) and were not (CHO-) transfected with a human mutation of amyloid precursor protein that appears to cause early-onset Alzheimer's disease. The 7PA2 CM, which contained concentrations of soluble amyloid-β oligomers physiologically relevant to those found in human brain, significantly disrupted working memory in rats tested in a radial-arm maze. In contrast, CHO-CM, which did not contain such oligomers, had no effect on memory. The disruptive effects of 7PA2-derived amyloid-β oligomers, evident two hours after exposure, disappeared within a day. These findings are compared to results from 7PA2 CM tested under a complex procedure thought to measure aspects of executive function. The results confirm the disruptive effects of low-n amyloid-β oligomers and extend them to a well established rat model of memory.

Background and rationale Research interests regarding the psychopharmacology of salvinorin A have been motivated by the recreational use and widespread media focus on the hallucinogenic plant, Salvia divinorum. Additionally, kappa opioid (KOP) receptor ligands may have therapeutic potential in the treatment of some neuropsychiatric conditions, including drug dependence and mood disorders. Salvinorin A is a selective KOP agonist, but only a few studies have explored the discriminative stimulus effects of this compound. Objective This study compared the discriminative stimulus effects of salvinorin A and two synthetic derivatives of salvinorin B to the KOP agonists, U69,593 and U50,488. Materials and methods Sixteen male Sprague-Dawley rats trained to discriminate U69,593 (0.13 mg/kg, s.c., N=8) or U50,488 (3.0 mg/kg, i.p., N=8) under a fixed-ratio 20 schedule of food reinforcement were administered substitution tests with salvinorin A (0.125-3.0 mg/kg, i.p.). The animals trained to discriminate U69,593 were also administered substitution tests with salvinorin B ethoxymethyl ether (0.005-0.10 mg/kg, i.p.) and salvinorin B methoxymethyl ether (0.03-0.10 mg/kg, i.p.). Another eight rats were trained to discriminate 2.0 mg/kg salvinorin A and tested with U69,593 (0.04-0.32 mg/kg) and U50,488 (0.4-3.2 mg/kg). Results Salvinorin A and both synthetic derivatives of salvinorin B substituted completely for U69,593. Additionally, cross-generalization was observed between salvinorin A and both KOP agonists.Conclusion These findings support previous reports indicating that the discriminative stimulus effects of salvinorin A are mediated by kappa receptors. Future studies may assist in the development and screening of salvinorin A analogs for potential pharmacotherapy.

Atypical antipsychotic drugs (AAPDs) have been suggested to be more effective in improving cognitive impairment in schizophrenia than typical APDs, a conclusion supported by differences in receptor affinities and neurotransmitter efflux in the cortex and the hippocampus. More potent serotonin (5-HT) 2A than dopamine (DA) D 2 receptors antagonism, and direct or indirect 5-HT 1A agonism, characterize almost all AAPDs. Blonanserin, an AAPD, has slightly greater affinity for D 2 than 5-HT 2A receptors. Using microdialysis and ultra performance liquid chromatography-mass spectrometry/mass spectrometry, we compared the abilities of the typical APD, haloperidol, three AAPDs, blonanserin, lurasidone, and olanzapine, and a selective 5-HT 1A partial agonist, tandospirone, and all, except haloperidol, were found to ameliorate the cognitive deficits produced by the N-methyl-d-aspartate antagonist, phencyclidine, altering the efflux of neurotransmitters and metabolites in the rat cortex and nucleus accumbens. Blonanserin, lurasidone, olanzapine, and tandospirone, but not haloperidol, increased the efflux of cortical DA and its metabolites, homovanillic acid and 3,4-dihydroxyphenylacetic acid. Olanzapine and lurasidone increased the efflux of acetylcholine; lurasidone increased glutamate as well. None of the compounds significantly altered the efflux of 5-HT or its metabolite, 5-hydroxyindole acetic acid, or GABA, serine, and glycine. The ability to increase cortical DA efflux was the only shared effect of the compounds which ameliorates the deficit in cognition in rodents following phencyclidine.

This study determined the involvement of women as first authors and other authors for every article published in Experimental and Clinical Psychopharmacology, Pharmacology Biochemistry and Behavior, and Psychopharmacology in 1991, 1996, 2001, and 2006. Their involvement as editors also was determined. Women's participation as authors, but not as editors, slightly increased over time. In 2006, 43% of first authors, 38% of other authors, and 24% of editors were women. The gender of subjects was examined for the same years and journals, but could not be determined for 6% and 9% of articles employing nonhuman and human subjects, respectively. In 2006, when subjects' gender could be determined, 77% of articles involving nonhuman subjects used only males, 9% only females, and 14% both males and females. In articles using human subjects in that same year, 17% involved only males, 6% only females, and 77% both males and females. Women researchers clearly make substantial contributions to the psychopharmacology literature, but are nonetheless underrepresented as editors. Findings regarding subjects indicate that there is growing recognition of the importance of gender as a determinant of drug effects, although the vast majority of nonhuman studies continue to involve only male subjects.

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