Beneficial effect of fluorocarbon emulsion media on the function of neuromuscular preparations in vitro.

Inconceivable as it is, it has been proved that animals can survive after having had their blood massively or even totally replaced by emulsions of perfluorinated compounds in salines. "Bloodless" rats charged with an emulsion of perfluorotri-n-butylamine survived a five hour period in an atmosphere containing 50 "/, oxygen and 50 "/, carbon monoxide, i . e. in conditions where the transport of oxygen by the red cells is entirely blocked. This review discusses: 1) the experiments which have demonstrated the capability of blood substitutes based on perfluorinated compounds to sustain life; 2) the characteristics and preparation of the relevant peffluoro compounds and the production and handling of their emulsions; 3) their "physiology", i . e. toxicity, life-span in the blood-stream, effect on the organs and their functions, and excretion properties. Obstacles remaining to be overcome in order to provide a safe blood substitute for medical practice include the availability of numerous series of well-defined pure and inert perfluorinated chemicals, the production of stable emulsions, the optimization of fluid balance, and the attainment of reasonable excretion rates. The accent is placed upon the role of the chemist in the progress of this research.

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A light and electron microscopic analysis of the mossy fibers of the rat dentate gyrus

Claiborne

Amaral

Cowan

1986

J of Comparative Neurology

454

328

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The axon collaterals of dentate granule cells have been analyzed with the aid of a computerized microscope, following intracellular injections of horseradish peroxidase in hippocampal slice preparations. The axon of each granule cell gives rise to approximately seven primary collaterals; these collaterals usually divide into secondary and tertiary branches, which form an extensive plexus within the hilar region of the dentate gyrus. Individual axon collaterals vary greatly in length, but most have been found to be between 100 and 300 microns long. On average, the summed lengths of the collaterals (exclusive of the parent mossy fiber) are approximately 2,300 microns. Except for an occasional collateral that is given off by a mossy fiber in the proximal part of field CA3 of the hippocampus, the collaterals of the granule cell axons are confined to the hilar region; they are rarely seen in the granule cell layer itself and have never been observed in the molecular layer. In the longitudinal dimension of the dentate gyrus, most of the collaterals are contained within a zone about 400 microns wide. The distribution of the collaterals within the hilar region is correlated with the location of the granule cell body. Those that arise from cells near the tip of the suprapyramidal blade tend to be confined to the region above field CA3; those from cells nearer the crest and from the infrapyramidal blade ramify widely throughout the hilus. Two types of varicosities are present on the collaterals. Numerous small (approximately 2 microns), round varicosities are distributed unevenly along the collaterals; in electron micrographs these varicosities can be seen to make asymmetric synaptic contacts with dendritic shafts. On average, each granule cell collateral plexus has about 160 of these varicosities. The second type of varicosity is irregular in shape and ranges from 2 to 4 microns in diameter; there is usually only one such varicosity per collateral. In all respects except size, these varicosities resemble the expansions found on the parent mossy fibers. Mossy fiber trajectories in the proximal part of field CA3 were studied after extracellular injections of HRP into localized regions of the granule cell layer. Granule cells at different locations around the blade send their mossy fibers to different depths within the pyramidal cell layer in the proximal part of field CA3. However, further distally, mossy fibers from all parts of the granule cell layer contribute to the suprapyramidal bundle that occupies the stratum lucidum.

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Beneficial effect of fluorocarbon emulsion media on the function of neuromuscular preparations in vitro.

Cited by 6 publications

References 18 publications

Perfluor-Verbindungen als Blutersatzmittel

Perfluor-Verbindungen als Blutersatzmittel

Perfluoro Compounds as Blood Substitutes

A light and electron microscopic analysis of the mossy fibers of the rat dentate gyrus

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