scholarly journals How Does Caffeine Influence Memory? Drug, Experimental, and Demographic Factors

2021 ◽  
Author(s):  
Ruochong Zhang ◽  
Christopher R Madan
Keyword(s):  
Dose Response ◽  
Reaction Times ◽  
Demographic Factors ◽  
Response Relationship ◽  
Limited Evidence ◽  
Dose Response Relationship ◽  
Future Studies ◽  
Nootropic Drug ◽  
Different Types ◽  
Healthy Participants

Caffeine is a widely used nootropic drug, but its effects on memory in healthy participants have not been sufficiently evaluated. Here we review evidence of the effects of caffeine on different types of memory, and the associated drug, experimental, and demographical factors. There is limited evidence that caffeine affects performance in memory tasks beyond improved reaction times. For drug factors, a dose-response relationship may exist but findings are inconsistent. Moreover, there is evidence that the source of caffeine can modulate its effects on memory. For experimental factors, past studies often lacked a baseline control for diet and sleep and none discussed the possible reversal of withdrawal effect due to pre-experimental fasting. For demographic factors, caffeine may interact with sex and age, and the direction of the effect may depend on the dose, individual tolerance, and metabolism at baseline. Future studies should incorporate these considerations, as well as providing continued evidence on the effect of caffeine in visuospatial, prospective, and implicit memory measures.

scholarly journals New Data on Variously Directed Dose-Response Relationships and the Combined Action Types for Different Outcomes of in Vitro Nanoparticle Cytotoxicity

Dose-Response ◽  
2021 ◽  
Vol 19 (4) ◽  
pp. 155932582110524
Author(s):  
Vladimir Panov ◽  
Tatiana Bushueva ◽  
Ilzira Minigalieva ◽  
Anna Naumova ◽  
Vladimir Shur ◽  
...  
Keyword(s):  
Dose Response ◽  
Copper Oxide Nanoparticles ◽  
Response Relationship ◽  
Combined Toxicity ◽  
Dose Response Relationship ◽  
Mathematical Expressions ◽  
Mean Diameter ◽  
Different Types ◽  
Combined Action

Spherical selenium-oxide and copper-oxide nanoparticles (SeO-NP with mean diameter 51 ± 14 nm and CuO-NP with mean diameter 21 ± 4 nm) were found to be cytotoxic for human fibroblast-like cells in vitro, as judged by decreased ATP-dependent luminescence. Compared with SeO-NP, CuO-NP produced a somewhat stronger effect of this kind. Along with cell hypertrophy developing in response to certain doses of SeO-NP and CuO-NP, our experiment also revealed doses causing a decrease in cell and cell-nucleus sizes. We observed both monotonic and different variants of nonmonotonic dose-response relationship. For the latter, we have succeeded in constructing adequate mathematical expressions based on the generalized hormesis paradigm that we had considered previously in respect of CdS-NP and PbS-NP cytotoxicity for cardiomyocites. It was demonstrated as well that combined toxicity of SeO-NP and CuO-NP is of different types depending on the outcome.

Succinylcholine-Induced Hyperkalemia: Dose-Response Relationship with Four Different Types of Pretreatment

2002 ◽  
Vol 96 (Sup 2) ◽  
pp. A1205
Author(s):  
Stephan Halbig ◽  
Peer Hofmann ◽  
Petra Meyer-Breiting ◽  
Hans-Joachim Wilke ◽  
Christian Byhahn
Keyword(s):  
Dose Response ◽  
Response Relationship ◽  
Dose Response Relationship ◽  
Different Types

scholarly journals Offset analgesia and onset hyperalgesia with different stimulus ranges

2020 ◽  
Author(s):  
Jens Fust ◽  
Maria Lalouni ◽  
Viktor Vadenmark Lundqvist ◽  
Emil Wärnberg ◽  
Karin B. Jensen
Keyword(s):  
Temperature Control ◽  
Dose Response ◽  
Opposite Effect ◽  
Large Body ◽  
Painful Stimulus ◽  
Large Reduction ◽  
Response Relationship ◽  
Dose Response Relationship ◽  
Healthy Participants ◽  
Pain Responses

ABSTRACTOffset analgesia (OA), a large reduction in pain following a brief increase in intensity of an otherwise stable painful stimulus, has been established by a large body of research. But the opposite effect, onset hyperalgesia (OH), a disproportional hyperalgesic response following a briefly decreased intensity of a painful stimulus, has only been investigated in one previous study. The aim of this study was to induce OA and OH in healthy participants and explore the effects of different stimulus ranges on OA and OH. A total of 62 participants were tested in two identical experiments. OA and OH conditions included two different temperature deviations (±1°C/±2°C) from baseline and were compared to a constant temperature (control). OA was successfully elicited in three out of four conditions. A dose-response relationship was demonstrated between the increase of temperature and the resulting hypoalgesic response. OH was only elicited in one out of four conditions (OH2°C in experiment 1). Exploratory analysis showed that OA and OH responses were only weakly correlated. The asymmetry between pain responses following a brief temperature increase and decrease could be seen as evidence for different mechanisms involved in the pain responses to increasing and decreasing temperature. This asymmetry may also be explained by high temperatures in OA condition (+1°C/+2°C above baseline) that could be seen as salient “learning signals”, which augment the response to following changes in temperature.

A SUBCUTANEOUS INJECTION ASSAY FOR ANTI-ANDROGENS IN THE CHICK

1962 ◽  
Vol 41 (2) ◽  
pp. 268-273 ◽  
Author(s):  
Ralph I. Dorfman
Keyword(s):  
Dose Response ◽  
Subcutaneous Injection ◽  
Response Relationship ◽  
Dose Response Relationship

ABSTRACT The stimulating action of testosterone on the chick's comb can be inhibited by the subcutaneous injection of 0.1 mg of norethisterone or Ro 2-7239 (2-acetyl-7-oxo-1,2,3,4,4a,4b,5,6,7,9,10,10a-dodecahydrophenanthrene), 0.5 mg of cortisol or progesterone, and by 4.5 mg of Mer-25 (1-(p-2-diethylaminoethoxyphenyl)-1-phenyl-2-p-methoxyphenyl ethanol). No dose response relationship could be established. Norethisterone was the most active anti-androgen by this test.

Mathematical Interpretation of the Pharmacodynamics of Homoeopathic Medicines

2021 ◽  
Vol 34 (01) ◽  
pp. 003-016
Author(s):  
John Michel Warner
Keyword(s):  
Immune System ◽  
Immune Responses ◽  
Dose Response ◽  
Oral Route ◽  
Response Relationship ◽  
Dose Response Relationship ◽  
Force Line ◽  
Administration Routes ◽  
Medicinal Substances ◽  
Medicine Administration

AbstractAccording to Hahnemann, homoeopathic medicines must be great immune responses inducers. In crude states, these medicines pose severe threats to the immune system. So, the immune-system of an organism backfires against the molecules of the medicinal substances. The complex immune response mechanism activated by the medicinal molecules can handle any threats which are similar to the threats posed by the medicinal molecules. The intersectional operation of the two sets, medicine-induced immune responses and immune responses necessary to cure diseases, shows that any effective homoeopathic medicine, which is effective against any disease, can induce immune responses which are necessary to cure the specific disease. In this article, this mechanism has been exemplified by the action of Silicea in human body. Also, a neuroimmunological assessment of the route of medicine administration shows that the oral cavity and the nasal cavity are two administration-routes where the smallest doses (sometimes even few molecules) of a particular homoeopathic medicine induce the most effective and sufficient (in amount) purgatory immune responses. Administering the smallest unitary doses of Silicea in the oral route can make significant changes in the vital force line on the dose–response relationship graph. The dose–response relationship graph further implicates that the most effective dose of a medicine must be below the lethality threshold. If multiple doses of any medicine are administered at same intervals, the immune-system primarily engages with the medicinal molecules; but along the passage of time, the engagement line splits into two: one engages with the medicinal molecules and another engages with diseases. The immune system's engagement with the diseases increases along the passage of time, though the engagement with the medicinal molecules gradually falls with the administration of descending doses. Necessarily, I have shown through mathematical logic that the descending doses, though they seem to be funny, can effectively induce the most effective immune responses.

Sign in / Sign up

Export Citation Format

Share Document