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J H Neale

Publications and source records attributed to J H Neale.

63 records · Page 4Linked to original sources
PubMed1976

Rapidly transported proteins in sensory, motor and sympathetic nerves of the isolated frog nervous system.

The synthesis and rapid axonal transport of [35S]methionine-labelled proteins has been studied using the isolated frog spinal cord and peripheral nervous system. Polyaerylamide gel electrophoresis in sodium dodecylsulfate of synthesized and transported proteins revealed similar labelling patterns of proteins transported in the sensory, motor and sympathetic systems. The relative labelling pattern of transported proteins which accumulated at ligatures in peripheral nerves was different from those obtained from ganglia or nerves and roots when they were incubated in labelled methionine. When compared with methionine-labelled protein profiles of rapid axonal transport in other species and systems, a common set of rapidly transported proteins emerges. The approximate molecular weights of these common proteins include (in 1000 daltons): 18,24-29, 34-36, 57, 65-68, 100 and 130. These proteins may represent fundamental macromolecules involved in the general maintenance of the function of nerve processes.

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PubMed1975

Localized catecholamine storage associated with granules in murine neuroblastoma cells.

Catecholamine storage was examined in cultures of the murine neuroblastoma cell line, N-TD6, using histofluorescence, electron microscopic, isotopic and radioautographic criteria. This line was originally derived from uncloned, C1300 tumor cells by selection in tyrosine deficient medium. N-TD6 cells possess both tyrosine hydroxylase (tyrosine-3-monooxygenase, EC 1.14.16.2) and dopamine beta-hydroxylase (dopamine beta-monooxygenase, EC 1.14.17.1) activities. When examined for paraformaldehyde-induced histofluorescence, a small percentage of cells in the population show intense catecholamine fluorescence, often localized within discrete regions of the cellular processes. Electron microscopic examination of these cells reveals both electron lucent vesicles and more frequent, electron dense granules, 50-70 nm and 100-300 nm in diameter, respectively. The distribution of these granules and vesicles varies, but they appear most numerous near the cell surface, along processes and within process endings. By labeling cells with [3H]dopamine and then allowing the cells to release unbound label in the presence of unlabeled dopamine, the localization of catecholamine stores was visualized by radioautographic techniques. While a variety of intracellular distribution of radioactivity were observed, the most prominent concentrations were found in the processes and their terminals; no labeled material was retained when reserpine was present during uptake. The topographic coincidence of granules, catecholamine fluorescence and [3H]dopamine retention in these neuroblastoma cells suggests that catecholamines are stored within these granules in a manner analogous to that observed in normal adrenergic neurons.

Animals↗
PubMed1975

Evaluation of [3-H]proline for radioautographic tracing of axonal projections in the teleost visual system.

The efficacy of [3-H]proline radioautography for tracing retinal ganglion cell projections to the optic tectum of the jewel fish, Hemichromis bimaculatus, has been compared with that of degeneration techniques. There was good agreement between the various methods. Retinal projections to the optic tectum of two other teleosts, the oscar, Astronotus ocellatus, and the goldfish, Carrasius auratus, were examined radioautographically. In addition to conventional methods of analysis, radioautograms were scanned in a slit microdensitometer and by an automated isodensity scanning system. Results of studies with the protein synthesis inhibitor, cycloheximide, are compatible with the suggestion that axonally transported proteins labeled with [3-H]proline may release diffusible precursors that are reincorporated into protein in adjacent regions. The possible advantages and limitations of radioautography of [3-H]proline-labeled axonally transported protein in brief or extended studies are discussed in terms of the results obtained in the teleost visual system.

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PubMed1973

Camptothecin blocks memory of conditioned avoidance in the goldfish.

Intracranial injection of 10 to 75 micrograms of camptothecin, a plant alkaloid that blocks RNA synthesis in eucaryotic cells, blocks incorporation of tritiated uridine into RNA in the goldfish brain. Injection of 10 to 50 micrograms of the drug within 1.5 hours of training results in greatly diminished memory, tested 1 week later. Injection of the drug 5 or 24 hours after training produces no measurable effect on retention of the learned response.

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PubMed1972

Radioautography of the optic tectum of the goldfish after intraocular injection of ( 3 H)proline.

Radioautography of the optic tectum of the goldfish, performed after injection of [(3)H]proline into the contralateral eye, effectively resolves several distinct layers of retinal synapses. Silver grains are found unilaterally over nerve tracts containing efferent fibers from the tectum, a result that suggests intercellular migration of labeled molecules. The low background and high specific grain density obtained with [(3)H]proline radioautography indicate the usefulness of this technique for the elucidation of neuroanatomical connections in the visual system.

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