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Biomedical subjects

G R Siggins

Publications and source records attributed to G R Siggins.

At least 109 records · Page 6Linked to original sources

Noradrenergic stimulation of cyclic adenosine monophosphate in rat Purkinje neurons: an immunocytochemical study.

A specific immunofluorescent histochemical method for cyclic adenosine monophosphate was used to study rat cerebellum. After topical treatment with norepinephrine or stimulation of norepinephrine-containing afferents from locus coeruleus, there was a striking increase in the number of Purkinje cells with strong cyclic adenosine monophosphate reactivity. Other putative inhibitory transmitters had no significant effect on staining of Purkinje cells. The results provide the first histochemical support for the hypothesis that cyclic adenosine monophosphate can be generated postsynaptically in central neurons in response to noradrenergic stimuli.

Aminobutyrates↗

Adenosine 3',5'-monophosphate is localized in cerebellar neurons: immunofluorescence evidence.

Adenosine 3',5'-monophosphate is localized in specific cerebellar neurons, as shown by fluorescence immunocytochemistry with a specific rabbit immunoglobulin. Positive staining is exhibited by Purkinje neurons and granule cells. The increase in concentration of cyclic adenosine monophosphate in the cerebellum, which is known to follow decapitation, is represented by greatly increased fluorescence of Purkinje neurons only. These immunofluorescence data provide the first evidence for localization of cyclic adenosine monophosphate in specific neurons and may permit further exploration into the role of this cyclic nucleotide in neuronal function.

Animals↗

Cyclic adenosine monophosphate and norepinephrine: effects on transmembrane properties of cerebellar Purkinje cells.

Electrical properties of Purkinje cells were recorded by intracellular microelectrode during extracellular electrophoretic application of gamma aminobutyrate, norepinephrine, cyclic adenosine monophosphate, and dibutyryl cyclic adenosine monophosphate. All these substances hyperpolarized Purkinje cells. Transmembrane resistance decreased during gamma aminobutyrate hyperpolarization. In contrast, norepinephrine and the cyclic nucleotides generally elevated resistance. These results show that cyclic nucleotides mimic the unique effects of norepinephrine on the bioelectric properties of neuronal membranes.

Adenine Nucleotides↗