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Biomedical subjects

J G Robson

Publications and source records attributed to J G Robson.

At least 37 records · Page 2Linked to original sources
PubMed1982

A new approach to the study of binocular interaction in visual cortex: normal and monocularly deprived cats.

Retinal disparity sensitivity was examined for cells in areas 17 and 18 of the cat's visual cortex. As a stimulus, we used drifting sinusoidal gratings which were spatially phase-shifted in one eye with respect to the other. The gratings were of high contrast (80%) and optimal values of spatial and temporal frequencies and orientations were used. In the normal cat cortex, binocular cells in areas 17 and 18 were all sensitive to phase shifts, but only minimal effects were observed for monocular cells. Recordings were also made from monocularly deprived cats, but no binocular influence was found from the silent eye.

Animals↗
PubMed1981

Brain death.

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Brain Death↗
PubMed1981

Brain death.

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Brain Death↗
PubMed1969

The yellow colour of the lens of the grey squirrel (sciurus carolinensis leucotis).

1. The absorption spectrum of the lens of the grey squirrel (Sciurus carolinensis leucotis) has been measured, revealing an absorption maximum at 370 nm. Peak densities in the intact lens ranged from 12 to 20.2. This peak is not present in the lenses of horse, cow, pig, dog, cat, ferret (Mustelo furo), or guinea-pig (Cavia porcellus).3. The pigment responsible for this absorption is water-soluble and aqueous extracts have been examined. Protein-free aqueous extracts show an additional maximum at 265 nm, which can only partially be accounted for by the presence of ascorbic acid.4. The absorption spectrum of extracts of lens material from the ground squirrel (Citellus mexicanus) also had maxima at 265 and 370 nm.5. Chromatography of the protein-free solution separated two yellow components, both of which had a yellow fluorescence. The faster component had a very similar absorption spectrum to the original protein-free solution.6. Possible functions of the yellow pigment are discussed.

Animals↗
PubMed1969

The yellow colour of the lens of man and other primates.

1. Measurements have been made of the absorption spectra of the lenses of human, baboon (Papio), rhesus monkey (Macaca), squirrel monkey (Saimiri sciureus) and bush baby (Galago crassicaudatus).2. In all these species an absorption maximum was found between 365 and 368 nm.3. The pigment responsible for this absorption was water-soluble and aqueous extracts were examined. Protein-free aqueous extracts showed an additional maximum at 260 nm which could be only partially accounted for by the presence of ascorbic acid.4. Chromatography of the protein-free solution from human lenses yielded a fast-moving yellow component with a blue fluorescence. Its absorption spectrum was very similar to that of the original protein-free solution. A fast-moving yellow component from the baboon lens had a yellow fluorescence.5. The human lenses appeared to contain more of the yellow, water-soluble pigment at birth than in adult life. The concentration remains constant during adult life.6. There is evidence for the appearance of another pigment in the human lens in later adult life. It is not water-soluble and has an absorption maximum at about 330 nm.

Adolescent↗