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P E Messier

Publications and source records attributed to P E Messier.

42 records · Page 3Linked to original sources

The effect of LSD on the histology and ultrastructure of the neuroepithelium of young chick embryos: a stereological study.

Five control chick embryos and fifteen exposed to LSD at concentrations of 2.5, 12.5 and 50 mug/ml were examined. The morphometric analysis performed at the light microscope level shows that (1) the section area of the neural tube increases with the two highest doses of lysergic acid diethylamide (LDS) employed, (2) the volume fraction of the intercellular spaces decreases with the two highest doses of LSD, (3) the volume fraction of the nuclei in the neural tube is not modified with any concentrations of LSD employed, (4) the volume fraction of the cytoplasm in the neural tube increases with all three concentrations, and (5) the nucleo-cytoplasmic ratio decreases with all three doses employed. Moreover, at the ultrastructural level, it was found that (1) the volume fraction of mitochondria in the cytoplasm decreases at doses of 12.5 and 50 mug/ml (2) the surface to volume ratio of the mitochondria is unchanged with any of the concentrations of LSD employed and (3) the surface density of the endoplasmic reticulum in the cytoplasm increases only with a dose of 2.5 mug/ml of LSD.

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[Morphometric analysis of neural tube cells in neurulating chick embryos].

Preliminary report on a morphometric study of the neuroepithelium of 1 S and 7 S -- stage chick embryos. We show first that the nucleo-cytoplasmic ratio and then, that the volume fraction of intercellular spaces, nuclei and cytoplasm as they relate to the neural tube, differ significatively from cephalic to caudal portion of the neural tube. At stage 7 S only the volume fraction of intercellular spaces, nuclei and cytoplasm in the neural tube change along the cephalo-caudal axis of the embryos. Finally, between the two stages, at the back of the head, 1) volume fraction of intercellular spaces in the neural tube remains unchanged 2) nucleo-cytoplasmic ratio increase 3) volumetric density and size of mitochondria do not change, while surface density of endoplasmic reticulum in cytoplasm increases.

Animals↗