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Biomedical subjects

J D Connor

Publications and source records attributed to J D Connor.

At least 145 records · Page 8Linked to original sources
PubMed1970

Hemizygous expression of glucose-6-phosphate dehydrogenase in erythrocytes of heterozygotes for the Lesch-Nyhan syndrome.

In women heterozygous for hypoxanthine guanine phosphoribosyl trasferase deficiency, the activity of this enzyme in the erythrocyte is usually normal. In a key kindred two such obligate heterozygotes were also heterozygous for glucose-6-phosphate dehydrogenase types A and B. The AB genotype was confirmed in one by assay of skin fibroblasts. Erythrocytes were exclusively of type B. These observations suggest the clonal origin of the hematopoietic system in these women from a primordial cell line with a single active X chromosome.

Cell Line↗
PubMed1970

Caudate nucleus neurones: correlation of the effects of substantia nigra stimulaton with iontophoretic dopamine.

1. Extracellular recordings were made from caudate nucleus neurones in decerebrate cats using five-barrel micropipette electrodes.2. Electrical stimulation of the substantia nigra caused spike rate depressions in 121 of 260 caudate neurones as evidenced by changes in the post-stimulus histograms of their firing patterns. Spike rate facilitation occurred with forty-two caudate units.3. Neurones depressed by nigral stimuli were consistently depressed by micro-iontophoretic dopamine.4. Alpha-methyldopamine, administered iontophoretically, antagonized the depressant responses induced by both nigral stimulation and iontophoretic dopamine.5. The data are compatible with the concept that the caudate neuronal depressant responses produced by nigral stimulation are mediated by a direct dopaminergic nigro-neostriatal pathway. The possibility of mediation via polysynaptic pathways cannot, however, be completely excluded.

Acetylcholine↗
PubMed1968

Caudate unit responses to nigral stimuli: evidence for a possible nigro-neostriatal pathway.

Electrical stimulation of the Substantia nigra evokes depressant and facilitatory responses from individually recorded caudate nucleus neurons. These effects resemble those elicited from caudate cells by microiontophoretic ejections of dopamine. Since histochemical evidence suggests that dopamine-containing fibers link the substantia nigra with the caudate, this pathway may mediate the changes in caudate spike rates produced by nigral stimuli.

Animals↗