scispace - formally typeset
Search or ask a question
Author

Eduardo De Robertis

Bio: Eduardo De Robertis is an academic researcher from University of Buenos Aires. The author has contributed to research in topics: Free nerve ending & Synaptic vesicle. The author has an hindex of 39, co-authored 94 publications receiving 5100 citations. Previous affiliations of Eduardo De Robertis include Facultad de Ciencias Médicas & National Scientific and Technical Research Council.


Papers
More filters
Journal ArticleDOI
TL;DR: The pineal body of white normal rats, 1.5 to 3 months old, was studied under the electron microscope, and a single type of parenchymal cell—the pinealocyte—is recognized as the main component of the tissue, and some of the structural characteristics of the nucleus and cytoplasm are described.
Abstract: The pineal body of white normal rats, 1.5 to 3 months old, was studied under the electron microscope. A single type of parenchymal cell—the pinealocyte—is recognized as the main component of the tissue, and some of the structural characteristics of the nucleus and cytoplasm are described. The main morphological characteristic of the pinealocytes is represented by club-shaped perivascular expansions connected to the cell by thin pedicles. They are found lying in a large, clear space surrounding the blood capillaries. The name plurivesicular secretory processes is proposed, to emphasize the main structural feature and the probable function of these cellular expansions. A tubulofibrillar component is mainly found in the pedicle, and within the expansion there are numerous small mitochondria and densily packed vesicles of about 425 A. Two types of vesicles, one with a homogeneous content and another with a very dense osmium deposit, are described. Between the two types there are intermediary forms. In these processes, mitochondria show profound changes which may lead to complete vacuolization. The significance of this plurivesicular secretory component is discussed in the light of recent work on the biogenic amines of the pineal body and preliminary experiments showing the release of the vesicles containing dense granules after treatment with reserpine. These vesicles are interpreted as the site of storage of some of the biogenic amines. Bundles of unmyelinated nerve fibers and endings on large blood vessels which also contain a plurivesicular content are described and tentatively interpreted as adrenergic nerve terminals.

163 citations

Journal ArticleDOI
12 Mar 1971-Science
TL;DR: Preliminary work indicates the possibility of obtaining a biophysical response to acetylcholine when the receptor proteolipid is embedded in artificial bilayered lipid membrance.
Abstract: A special proteolipid (a hydrophobic protein) has been extracted and purified from nerve-ending membranes and total particulate matter of gray areas of the central nervous system. Such a proteolipid shows a high affinity for binding d-tubocurarine, serotonin, and atropine and has been called receptor proteolipid. The interaction of this proteolipid with atropine sulfate was studied with light scattering and polarization of fluorescence. The changes observed, which follow a cooperative type of curve, were attributed to the aggregation of the proteolipid macromolecules. Such a phenomenon was then observed under the electron microscope. A receptor proteolipid having a high affinity for binding acetylcholine, hexamethonium, and other cholinergic drugs was isolated and purified from electric tissue of fishes and from electroplax membranes. Such a proteolipid was also extracted from membranes from which acetylcholinesterase had been removed, and it was concluded that this enzyme and the receptor proteolipid are two different macromolecules. A high affinity binding site with a dissociation constant of K1 equal to 10 -7 and about ten sites with K2 equal to 10 -5 were recognized in the receptor proteolipid. Under the electron microscope the receptor proteolipid of brain appears as a rod-shaped macromolecule which may assume paracrystalline arrays with 10 -8 molar atropine sulfate. Similarly the receptor proteolipid from electric tissue and from skeletal muscle may form paracrystalline arrays under the action of acetylcholine and hexamethonium. A model of the cholinergic receptor based on the properties of the proteolipid is presented. Preliminary work indicates the possibility of obtaining a biophysical response to acetylcholine when the receptor proteolipid is embedded in artificial bilayered lipid membrance.

151 citations


Cited by
More filters
Journal ArticleDOI
TL;DR: This review focuses on work that deals with the mechanisms of detergent action in membrane solubilization including properties of detergents model lipid systems and detergent-protein interactions; in addition a possible sequence of events when deterGents interact with biological membranes receives attention.

2,850 citations

Journal ArticleDOI

2,446 citations

Journal ArticleDOI
TL;DR: Understanding how BBB TJ might be affected by various factors holds significant promise for the prevention and treatment of neurological diseases.
Abstract: The blood-brain barrier (BBB) is the regulated interface between the peripheral circulation and the central nervous system (CNS). Although originally observed by Paul Ehrlich in 1885, the nature of the BBB was debated well into the 20th century. The anatomical substrate of the BBB is the cerebral microvascular endothelium, which, together with astrocytes, pericytes, neurons, and the extracellular matrix, constitute a "neurovascular unit" that is essential for the health and function of the CNS. Tight junctions (TJ) between endothelial cells of the BBB restrict paracellular diffusion of water-soluble substances from blood to brain. The TJ is an intricate complex of transmembrane (junctional adhesion molecule-1, occludin, and claudins) and cytoplasmic (zonula occludens-1 and -2, cingulin, AF-6, and 7H6) proteins linked to the actin cytoskeleton. The expression and subcellular localization of TJ proteins are modulated by several intrinsic signaling pathways, including those involving calcium, phosphorylation, and G-proteins. Disruption of BBB TJ by disease or drugs can lead to impaired BBB function and thus compromise the CNS. Therefore, understanding how BBB TJ might be affected by various factors holds significant promise for the prevention and treatment of neurological diseases.

2,374 citations