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M Alvarez-Uría

Publications and source records attributed to M Alvarez-Uría.

31 records · Page 2Linked to original sources
PubMed1987

The dorso-lateral recess of the hypothalamic ventricle in neonatal rats.

Light and electron microscopy of the hypothalamic ventricle in neonatal rats demonstrate morphological specializations of the ventricular wall at the level of the premammillary region of the third ventricle. The morphological features are: (1) A ventricular recess that we have called the "hypothalamic dorso-lateral recess" (HDR). (2) The presence of intraventricular capillaries near the dorso-lateral recess. (3) The HDR possessing a specialized ependymal lining; this consists of non-ciliated cells with short microvilli and bleb-like processes. (4) The existence of cerebrospinal fluid-contacting neurons within the HDR. (5) The presence of numerous phagocytic supraependymal cells. The HDR is not found in adult rats. This indicates that the dorso-lateral recess may play a physiological role during development.

Aging↗
PubMed1987

Effects of superior cervical preganglionectomy on nerve vesicles and synaptic ribbons in the cat pineal gland.

Previous studies have shown that bilateral preganglionectomy of the superior cervical ganglia (SCGp) modifies the nerve vesicles and synaptic ribbons in the cat pineal gland. In the present study the nerve vesicles (NV) and synaptic ribbons (SR) were analyzed morphometrically after chronic preganglionectomy of the pineal sympathetic nerve fibers. It was shown that bilateral sympathectomy of the preganglionic fibers innervating the superior cervical ganglia (SCG) markedly reduces the number of dense cores of small dark vesicles (SDV) and, on the other hand, modifies the number and shape of the large dark vesicles (LDV). An increase in the number of the synaptic ribbons after chronic preganglionectomy of the SCG supports the hypothesis that the numerical reduction of dense cores of nerve vesicles in the cat pineal gland influences the level of synaptic ribbon formation.

Adrenergic Fibers↗
PubMed1987

The hypothalamic magnocellular system in the domestic fowl. Study on semithin sections.

Neuronal characteristics and location of the neurosecretory, magnocellular, fuchsin-paraldehyde-positive (FA+) system of the fowl are described at the light-microscopic level on serial semithin sections. Three nuclei make up this system, the nucleus supraopticus, n. magnocellularis interstitialis and n. paraventricularis. These nuclei display magnocellular neurons, not showing a parvocellular component. The neurons of the three nuclei showed a scattered pattern of distribution and a dense surrounding neuropil. Groups formed by magnocellular neurons were found in the three nuclei and groups formed by one magnocellular and a parvocellular neurons were only found in the n. magnocellularis interstitialis and in the n. paraventricularis. The presence of neurons in apposition to blood vessels was frequent in the magnocellular FA+ system of the domestic fowl.

Animals↗
PubMed1987

Nucleolus-like bodies in the posterior subnucleus of the rat paraventricular nucleus during postnatal development. An ultrastructural, cytochemical and morphometric study.

Dense intracytoplasmic bodies which lack surrounding membranes and referred to as nucleolus-like bodies (NLBs), have been observed in the big sized neurons of the rat posterior subnucleus in the hypothalamic paraventricular nucleus (PVNP) during neonatal stages. The NLBs suddenly appear from 8th to 16th postnatal days, coinciding with an increase of the nuclear activity in these neurons. NLBs present a granular aspect, showing a close morphological association with ribosomes and rough endoplasmic reticulum. The specific silver-staining procedure used in the study of the nucleolar organizing regions shows no silver grains deposited in the NLBs. The hypothetical nuclear origin of NLBs and the relationship of its frequency within the neuronal cytoplasm, when an increased protein synthesis process takes place, are discussed.

Aging↗
PubMed1986

Intraventricular blood vessels of the hypothalamus of Salmo gairdneri and Gambusia affinis.

The ultrastructure of the hypothalamic intraventricular blood vessels is studied in two fish: Salmo gairdneri, a primitive teleost and Gambusia affinis, a modern teleost. Morphological differences found between vessels belonging to the lateral and medial recesses in Salmo are described as well as contrasted with those of Gambusia. The endothelial cells are joined by elaborate tight junctions in both teleosts and also by desmosomes in Gambusia. These vessels are continuous capillaries with pericytes which lack junctional complexes. The perivascular cells of the larger vessels display morphological characteristics of myoid cells.

Animals↗
PubMed1986

A threedimensional reconstruction program for personal computers.

A reconstruction program is described for personal computers, permitting threedimensional image reconstructions from serial sections. This program also makes it possible to calculate the volume of structures from their twodimensional images in histological sections. In this paper we show a program written in BASIC and debugged on a Sharp MZ-700 personal computer, equipped with the Sharp MZ-1P01 plotter. The program is explained in detail and is easily adapted to run on any personal computer.

Computers↗
PubMed1982

Ultrastructure of the "smooth endoplasmic reticulum cell" in the nucleus recessus lateralis of Salmo gairdneri Richardson.

The fine structure of one of the cellular components of the nucleus recesses lateralis of trout is described. These cells have an enormously developed smooth endoplasmic reticulum which makes their identification easy. The relationship of this cell type with the ventricular cavity, neighbouring cells and the presence of synaptic contacts with these cells are also described.

Animals↗
PubMedDate not supplied

The rat pinealocyte during the oestrous cycle. A morphometric study.

The involvement of the pineal gland in the oestrous cycle seems to be clear nowadays according to various types of studies, although its exact functional mechanism remains unknown. The lack of morphological studies on the pineal gland throughout the oestrous cycle has drawn us into the quantification of the surface of pinealocyte nucleoli and nuclei and lipid contents (expressed in mean area of lipid droplets with respect to the total area of pinealocytes) in each of one of the four days of the oestrous cycle: Prooestrous, oestrous, metoestrous and dioestrous. The measures of nuclei and lipid droplets were taken on photographs that were obtained from 1 micron thick sections by means of an image analyzer and the measures of nucleoli were obtained from micrography by means a point-counting analysis. One-way analysis of variance showed significant differences among nucleolar surface during the four days of the cycle. Nucleolar surface in prooestrous and oestrous was significantly smaller than in metoestrous and dioestrous and nuclear surface showed higher values in dioestrous and proestrous than oestrous and metoestrous. The relative value of lipid surface with respect to pinealocyte surface showed significant differences between oestrous and the other three days, with their minimum value in oestrous and maximum in metoestrous. We conclude that the pinealocyte have a rhythmic activity during the oestrous cycle, with a minimum close to ovulation, where the pituitary gonadotropins and ovarian hormonal levels presents a surge.

Animals↗