Biomedical subjects

R Brandeis

Publications and source records attributed to R Brandeis.

23 records · Page 2Linked to original sources

PubMed1989

The use of the Morris Water Maze in the study of memory and learning.

Although the Morris Water Maze (MWM) was introduced only a few years ago, this technique has gained wide popularity, as the large number of publications in which it is employed, testifies. A review of the literature reveals that a wide variety of technical variables were used by the various research groups employing the MWM. This review describes the major changes in research variables, i.e., environmental variables, various manipulations, and the effects of diet or age on performance. The general principles of learning as demonstrated by the MWM are discussed.

Animals↗

PubMed1987

Glucocorticoids control phosphoenolpyruvate carboxykinase gene expression in a tissue specific manner.

Cytosolic Phosphoenolpyruvate carboxykinase is a key gluconeogenic enzyme which is expressed in a tissue specific manner in the liver, kidney and adipose tissue and is under hormonal control. The effect of glucocorticoids on expression of the gene coding for phosphoenolpyruvate carboxykinase in adipose tissue has been studied in vivo in rats and in vitro in adipose tissue organ culture and mouse 3T3 L1 adipocytes. Glucocorticoids, both in vivo and in vitro, repress the steady state level of phosphoenolpyruvate carboxykinase mRNA in the adipose tissue while increasing it in the kidney. The size of the mRNA and its 5' end are identical in adipose tissue and kidney, thus the same promoter is used in all tissues. The inhibitory effect of glucocorticoids on phosphoenolpyruvate carboxykinase gene expression was located at the level of transcription. As glucocorticoids are known to stimulate transcription of phosphoenolpyruvate carboxykinase gene in the liver and kidney, the inhibitory effect on its transcription in adipose tissue suggests that tissue specific transcription factors may modulate the effect of glucocorticoids.

Adipose Tissue↗

PubMed1985

Individual use of judgmental dimensions and hemispheric specificity.

The present study investigated the relationship of hemispheric functional specificity to a subject's use of judgmental dimensions when discriminating temporal and spatial visual stimuli using a multidimensional scaling (MDS) paired-comparison paradigm. The major purposes of the study were: To identify the judgmental dimensions used in discriminating unidimensional (temporal or spatial) and multidimensional (combinations of temporal and spatial parameters) stimuli presented to the two visual hemifields; to study the relationship of the use of judgmental dimensions to the visual hemifields; to investigate whether the use of judgmental dimensions in discriminating unidimensional stimuli can be used to predict their use in discriminating multidimensional stimuli. Subjects used two dimensions in discriminating the spatial and temporal unidimensional stimuli: A dimension whose scaling paralleled the physically interval-scaled stimuli; a dimension, in which the extreme values were located on one end of the scale, while the mid-values are located at the other end of the scale. There is significantly greater use of the spatial dimension when spatial stimuli are presented to the left visual field (LVF) then when presented to the right visual field (RVF). Conversely, there is significantly greater use of the temporal dimension when temporal stimuli are presented to the RVF then when they are presented to the LVF. Three perceptual dimensions were used to judge multidimensional stimuli: Spatial-to-temporal; stimulus quality; apparent movement. Two groups of subjects were identified who differed in their relative use of the temporally and spatially scaled unidimensional stimuli presented to the RVF. These two groups differed with respect to their relative use of a spatial-to-temporal dimension when multidimensional stimuli were presented to the RVF.

Cues↗

PubMed1984

Sorting of hemifield presented temporal and spatial stimuli.

An experiment was performed, using a sorting task (choice reaction-time), to study the processing of stimuli, which differed along a temporal or a spatial dimension, presented to the right or to the left visual hemifield. The results indicate more accurate responses and shorter reaction times to a temporal stimulus when it appears in the right-visual-field than when it appears in the left-visual-field. Conversely, more accurate responses and shorter reaction times are found to a spatial stimulus when it appears in the left-visual-field than when it appears in the right-visual-field. In addition to this major interaction, three more interactions are found, all of which involve response direction and one or two other stimulus variables. The results are consistent with the hypothesized hemispheric functional specificity, i.e., that the initial processing of the temporal dimension of visual stimuli is performed better by the left hemisphere than by the right hemisphere and that the converse is true for the initial processing of the spatial dimension of visual stimuli.

Discrimination Learning↗

PubMedDate not supplied

Novel m1 muscarinic agonists in treatment and delaying the progression of Alzheimer's disease: an unifying hypothesis.

M1 selective agonists from the AF series (e.g. AF102B, AF150(S)), via m1 muscarinic receptors, activate distinct signal transductions, enhance amyloid precursors proteins secretion from transfected cells and primary cell cultures, show neurotrophic effects and are beneficial in a variety of animal models for Alzheimer's disease. Such m1 agonists may be effective in the treatment and therapy of Alzheimer's disease.

Alzheimer Disease↗