Biomedical subjects

G M Ross

Publications and source records attributed to G M Ross.

40 records · Page 3Linked to original sources

PubMed1985

Factors affecting solubilization of the D1 receptor from bovine caudate nucleus.

The D1 dopamine receptor was identified using the dopamine agonist 3H-ADTN. The ability of various detergents to solubilize this receptor from bovine caudate nucleus was examined. In order to maintain high affinity binding, receptors were solubilized in the presence of dopamine and manganese. GPP(NH)P reduced the yield of soluble receptors. Of the detergents tested, n-octyl-B-D-glucopyranoside gave the best yield of receptors capable of binding 3H-ADTN and related compounds with high affinity.

Animals↗

PubMed1976

Did Ptolemy understand the moon illusion?

Ptolemy is often wrongly credited with an explanation of the moon illusion based on the size-distance invariance principle. This paper elucidates the two Ptolemaic accounts: one in the Almagest, based on atmospheric refraction, and the other in the Optics, based on the difficulty of looking upwards. It is the latter passage which has been thought to refer to size-distance invariance, but it is more probable that it refers to the idea that the visual rays are diminished by the force of gravity (i.e. that the retinal image is reduced in size). Alhazen was probably the first author to explain the illusion by the size-distance invariance principle, and Roger Bacon the first to explain the enlarged apparent distance of the horizon by the presence of intervening objects. Della Porta was the first to credit Ptolemy with these explanations, and this mistake was repeated by many subsequent authors.

Astronomy↗

PubMed1974

[Not Available].

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Academies and Institutes↗

PubMedDate not supplied

Effects of unilateral intracerebroventricular microinjections of cholecystokinin (CCK) on circling behavior of rats.

Unilateral intracerebroventricular (ICV) injections of a high dose of CCK7 have been reported to elicit barrel rotations accompanied by contralateral postural asymmetry; there was no spontaneous locomotor activity other than barrel rolling. The aim of the present study was to investigate the effects of lower doses of CCK-peptides on circling behavior; it was reasoned that if ambulation was present following unilateral ICV administrations of lower doses of CCK, then the contralateral postural asymmetry previously reported might be expressed as contraversive circling. In the present study, spontaneous locomotor activity was observed following ICV injections of lower doses of CCK sulfated octapeptide (CCK8), desulfated CCK octapeptide (dCCK8) and CCK tetrapeptide (CCK4). As postulated, contraversive circling was induced by CCK8 (0.5-5000 ng, ICV); the two other CCK fragments, dCCK8 and CCK4, were inactive in this respect. In addition, the contraversive circling bias induced by CCK8 (5.0 ng, ICV) was attenuated by co-injections of the CCK antagonist proglumide (10 and 100 ng) and by intraperitoneal injections of the dopamine (DA) antagonist haloperidol (0.05 and 0.1 mg/kg, 45 min prior to ICV CCK8). These data suggest that the effect is medited by CCK receptors and through a facilitatory influence on central DA function.

Animals↗