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B Droz

Publications and source records attributed to B Droz.

At least 73 records · Page 4Linked to original sources
PubMed1970

Intraneural distribution of exogenous norepinephrine in the central nervous system of the rat.

Catecholaminergic neurons, which take up and retain exogenous norepinephrine labeled with tritium, were studied by means of high resolution radioautography, in the substantia nigra, the substantia grisea periventricularis, and the locus coeruleus of the rat. Under the conditions required for the radioautographic detection of exogenous norepinephrine-(3)H, it was established that (1) glutaraldehyde was the most suitable fixative for preserving the labeled amine in situ; (2) norepinephrine-(3)H itself, rather than metabolites, accounted for most of the reactions detected in catecholaminergic neurons. At various time intervals after an intraventricular injection of norepinephrine-(3)H, the tracer reached a concentration 15-100 times higher, and disappeared at a slower rate, in presynaptic axons (t(1/2):4 hr) than in nerve cell bodies (t(1/2):0.8-1.3 hr). After pretreatment with a monoamine oxidase inhibitor, the radioautographic reactions increased and persisted longer, especially in the preterminal axons. Within neurons, the labeled amine was ubiquitously distributed in the nerve cell body and concentrated in presynaptic axons and synaptic terminals of various morphological types. Although large granular vesicles were usually present in the labeled axonal bulbs, no structural characteristic could be specifically ascribed to catecholaminergic neurons. It is suggested that exogenous norepinephrine bound to macromolecular complexes is present in all parts of catecholaminergic neurons and mainly concentrated within presynaptic axons.

Animals↗
PubMed1969

Nerve endings: rapid appearance of labeled protein shown by electron microscope radioautography.

Electron microscope radioautographs of nerve ending fractions from mouse cerebrum show that radioactive protein is associated with nerve endings 15 and 90 minutes after intracerebral injection of tritiated leucine and lysine. The results are consistent with synthesis of protein at nerve endings, or with extremely rapid transport of particulate protein to nerve endings in the mouse cerebrum, or both.

Animals↗
PubMed1968

The renewal of protein in retinal rods and cones.

The renewal of protein in retinal rods and cones has been analyzed by quantitative electron microscope radioautography in adult frogs injected with a mixture of radioactive amino acids. Protein synthesis occurs predominantly in the ergastoplasm, localized in the myoid region of the photoreceptor cells. Much of the newly formed protein next flows through the Golgi complex. In rods, a large proportion of the protein then moves past the mitochondria of the ellipsoid segment, passes through the connecting cilium into the outer segment, and is there assembled into membranous discs at the base of that structure. Discs are formed at the rate of 36 per day in red rods and 25 per day in green rods at 22.5 degrees C ambient temperature. In cones, a small proportion of the protein is similarly displaced to the outer segment. However, no new discs are formed. Instead, the protein becomes diffusely distributed throughout the cone outer segment. Low levels of radioactivity have been detected, shortly after injection, in the mitochondria, nucleus, and synaptic bodies of rods and cones. Nevertheless, in these organelles, the renewal process also appears to involve the utilization of protein formed in the ergastoplasm of the myoid.

Amino Acids↗