1,721,101 research outputs found
A radioenzymatic method to measure picogram amounts of dopamine and 3,4-dihydroxyphenylacetic acid(DOPAC) in small samples of brain tissue.
Hippocampal acetylcholine release correlates with spatial learning performance in freely moving rats
Hippocampal acetylcholine release progressively increase during the learning of a spatial task
Memory deficits induced by spontaneous ethanol consumption in sP rats are associated with a diminished release of hippocampal acetylcholine
Vitamin A deficiency affects neither frontocortical acetylcholine nor working memory
Vitamin A is quite often implicated in supporting acetylcholine synthesis. Choline acetyltransferase, the enzyme promoting acetylcholine synthesis, and the vesicular acetylcholine transporter are modulated by retinoic acid treatment. This paper illustrates the effect of vitamin A deprivation on acetylcholine content in the hippocampus, striatum and prefrontal cortex of rats, brain regions containing retinoid acid receptors. The effect of vitamin A deprivation on working memory was also examined. The results obtained demonstrate a decrease in acetylcholine content following 12 weeks vitamin A deprivation in the hippocampus and striatum, but not in prefrontal cortex. Working memory performance assessed in the same rats was unaffected, suggesting a higher susceptibility of hippocampus and striatum to vitamin A deficiency, in terms of cholinergic transmission
Tryptophan-deficient diet increases the neurochemical and behavioral response to amphetamine
The present study examined the effects of a tryptophan-deficient diet on behavioral and neurochemical response to amphetamine. A tryptophan-deficient diet (14 days) decreased striatal serotonin and 5-hydroxyindolacetic acid content in rats. Under the latter conditions, amphetamine increased dopamine efflux in striatum and nucleus accumbens and produced a greater increase in motor activity when compared to controls. These results indicate how response to psychostimulants might be altered in the presence of a tryptophan-deficient diet
Going Beyond Counting First Authors in Author Co-citation Analysis
The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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