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Biomedical subjects

E Marani

Publications and source records attributed to E Marani.

At least 109 records · Page 6Linked to original sources
PubMed1990

Morphological and functional properties of rat dorsal root ganglion cells cultured in a chemically defined medium.

A culture procedure for dorsal root ganglion (DRG) cells is presented using a completely defined culture medium without antibiotics, in combination with mechanical dissociation procedures. This culture procedure allows all dorsal root ganglion cell types to be cocultured for periods of at least 106 days. Some of the dorsal root ganglion neurons, which could be identified by their neurofilaments and the presence of fluoride resistant acid phosphatase, regained their original T-cell appearance within two weeks. After one month in culture ganglion-like reaggregates appeared. Schwann cells, satellite cells and fibroblasts were identified using morphological criteria. All neurons tested maintained excitability during, at least, the first 35 days in culture, since in all cases action potentials could be evoked by current pulses. The method has proved to be useful in the study of morphological, cytochemical and electrophysiological aspects of dorsal root ganglion cell differentiation in vitro.

Acid Phosphatase↗
PubMed1989

Aluminum affects interconnections between aggregates of cultured hippocampal neurons. Neurotoxicity of aluminum in vitro.

The effect of aluminum (Al) was studied in an in vitro system of cultured hippocampal neurons from fetal rats in a chemically defined medium. Neuronal aggregates interconnected by neurites were detected light and electron microscopically in control and Al-treated cultures. In the Al-treated cultures disruptions of the fibers were observed proximal to the aggregates; the number of disruptions increased with The Al concentration applied. It is concluded that interference of intracellular Al with the neuronal skeleton occurs, leading to an enhanced fragility of the interconnecting neurites. The concentration-dependent Al-induced disruption of interconnecting neurites may serve as an in vitro model for further research in Al neurotoxicity.

Aluminum↗
PubMed1988

A zonal pattern of neuroglial cells during the development of the intermediate lobe of the rat pituitary.

In this paper the development of the intermediate lobe (IL) of the pituitary of the rat is described using alkaline phosphatase (AP) (EC 3.1.3.1.) enzyme histochemistry and stage-specific embryonic antigen 1 (SSEA-1) immunocytochemistry. SSEA-1 and AP are co-localized during late development and reveal the existence of two cytochemically different cell types within the IL, i.e. SSEA-1/AP-positive and SSEA-1/AP-negative cells. The SSEA-1/AP-positive cells are initially arranged along the hypophyseal lumen, in a number of longitudinally oriented zones. alpha-Melanocyte-stimulating hormone (alpha-MSH) immunoreactivity is expressed in the SSEA-1/AP-negative cells from E20 onwards. Eventually the SSEA-1/AP-positive cells develop into a layer of cells covering the luminal surface of the IL lobules. These cells represent the glio-epithelial or neuroglial cells of the IL.

Alkaline Phosphatase↗
PubMed1988

A SEM study on the development of the ventricular surface morphology in the diencephalon of the rat.

The morphogenesis of the ventricular surface of the diencephalon of the rat was studied using scanning electron microscopy, cryostat serial sections and direct observations under a dissection microscope. Based on these observations a description is given of the neuromeres present within the prosencephalon and of the termination of the sulcus limitans. Two conclusions are reached. First, three neuromeres are present in the prosencephalon. Neuromere I consists of the telencephalon, the hypothalamic regions and the parencephalon anterius. Neuromere II is the parencephalon posterius, neuromere III the synencephalon. Second, the sulcus limitans terminates ventrally in the parencephalon posterius and does not continue towards the preoptic recess. No exact termination point of the sulcus limitans could be delineated.

Animals↗
PubMed1988

Microwave irradiation of human brain tissue: production of microscopic slides within one day.

A three step method using microwave irradiation enabled microscopic slides of human brain tissue to be obtained within one working day: steps 1 and 2 hardened and solidified brain tissue; step 3 completed formalin fixation. The efficacy and precision of the method was compared with slides of conventionally processed brain tissue that had been fixed in formalin for six weeks. The microscopic quality of the sections was excellent with good presentation of brain tissue and equalled that of conventionally processed slides.

Adult↗
PubMed1988

Ionic conductances in cultured pre-infundibular cells from the hypothalamic arcuate region.

The hypothalamic arcuate nucleus plays an important role in the gating system controlling the secretion of hypothalamic neurons. In order to analyze this gating mechanism, arcuate neurons from rats aged 21-22 days were cultured in a chemically defined medium. Addition of nerve growth factor to this medium increased the survival of the arcuate neurons. Neuron characterization was done with the Lucifer Yellow liposome technique and neurofilament immunocytochemistry. Electrophysiological information was obtained with the patch-clamp technique by whole-cell recordings and single-channel measurements. This qualitative inventory demonstrated the presence of at least five types of conductances: a sodium conductance, two potassium conductances, a calcium-activated conductance, presumably determined by potassium, and a leakage conductance.

Animals↗
PubMed1988

The postnatal developmental localization of pro-opiomelanocortin and alpha melanocyte stimulating hormone in the medio-basal hypothalamus of the rat.

This immunocytochemical study of the late postnatal development of the medio-basal hypothalamus revealed the presence of ACTH 1-39 like positivity in neurons of the arcuate nucleus form the begin of this study (day E 18-20) onwards. Alpha MSH positivity, on the contrary, is not present in cells of the same area before day P 16. No other areas in the developing medio-basal hypothalamus contain perikaryal positivity for alpha M-SH or ACTH 1-39. The pituitary contains ACTH 1-39 like positivity from the begin of this study (day E 18-20) onwards. Fibers are positive for alpha MSH during the fetal development of the medio-basal hypothalamus, demonstrating an overal reactivity without varicosities and restricted to bundles or neuropil areas. Towards P 16 the alpha MSH positivity diminishes in the whole medio-basal hypothalamus, remaining present only in large fibre systems like the fornix. ACTH 1-39 like fiber positivity is already distributed in arcuate and periventricular regions at days E 20-PO, reaching its mature extension at day P2. After P16 alpha MSH positive threads, possessing varicosities are restricted to the same areas as ACTH 1-39 like fiber positivity is.

Adrenocorticotropic Hormone↗
PubMed1988

The fate of cerebellar allotransplants as determined with histochemical methods.

Allotransplants of cerebellar cell suspensions from neonate 1 day old rabbits into litter mates showed the survival of granule cells. No Purkinje cells survived this treatment. The transplanted granule cells kept their ability to express the Stage Specific Embryonic Antigen, indicating their recovery from the dissociation procedure and their positive selection of one cell type from the cell suspensions.

Acetylcholinesterase↗
PubMed1988

The prenatal development of alkaline phosphatase activity in the hypothalamus of the rat.

The localization of alkaline phosphatase (E.C. 3.1.3.1.) positivity during prenatal development of the hypothalamus of the rat is described. At E12 all layers of the prosencephalon display alkaline phosphatase (AP) positivity. The AP positivity increases from dorsal to ventral. Within the hypothalamic area a second, rostro-ventral gradient exists from E14 onwards. At E18 both gradients have decreased. At E20 almost all AP positivity has disappeared from the hypothalamus, with the exception of some reaction product in the dorsal ventricular matrix of the hypothalamus. The significance of this pattern in relation to the differentiation of the hypothalamus and to the formation of hypothalamic connections is discussed. It is suggested that AP activity is related to the formation of connections.

Alkaline Phosphatase↗
PubMed1987

Differential displacement of cells from the median eminence into the arcuate nucleus during puberty. Effects of melatonin administration.

A displacement of catecholaminergic-positive and catalase-containing cells from the median eminence into the arcuate nucleus at puberty has been described previously. This study reports on the displacement phenomena after postnatal administration of melatonin. Catalase-positive cells undergo a delayed displacement from the median eminence into the arcuate nucleus. However, part of this cell population lags behind within the median eminence. This differential reaction of cell displacement by catalase-positive cells is considered as a special reaction of these cells to melatonin administration.

Animals↗
PubMed1987

The microwave Rio-Hortega technique: a 24 hour method.

Application of microwaves in histochemistry and cytochemistry generally speeds up the technique. Microwaves stimulate diffusion into the tissue and influence the proteins and membrane of the cell. Silver impregnation techniques for the brain, such as the fast Rio-Hortega or the slow Golgi-Cox technique, normally require a minimum time period of 7 days and 20 days respectively. Using microwaves, the Rio-Hortega technique can be completed within 24 h. In sections prepared from mature brains, good silver impregnation of cell bodies, of axons and their terminals, and of dendrites and their spines are obtained. An explanation is given as to why the method cannot be further reduced in time. To our knowledge, this is the first report of the application of microwave irradiation for colouring pieces of tissue.

Animals↗
PubMed1987

Microwave-cryostat technique for neuroanatomical studies.

A novel method to process nervous tissue for neuroanatomical studies is presented. In this cryostat method, the brain tissue is first treated with microwave irradiation after perfusion with physiological saline. Cutting quality of the microwave-treated brain tissue was excellent. The sections were stained with the Nissl staining, the Klüver-Barrera method, and the Bodian method, respectively. In addition, immunocytochemistry using the RAM/PO method was performed. For the latter a monoclonal antibody against neurofilament (NF90), recognizing the 200, 150, and 70 kD units was used. Excellent results were obtained. The advantage of the microwave-cryostat technique for processing of nervous tissue is not merely a substantial reduction of time to obtain microscopical slides of good quality. This method allows in addition the estimation of the effect of fixation by formaldehyde in immunocytochemistry.

Animals↗
PubMed1987

Cell typing and connections of the rat suprachiasmatic nucleus.

Microiontophoretic delivery of horseradish peroxidase and Lucifer Yellow liposomes into several nuclei (arcuate nucleus, median eminence, ventromedial hypothalamic nucleus, and retrochiasmatic area) of the medial basal hypothalamus revealed an intrinsic pattern of connections to the suprachiasmatic nucleus that was correlated to immunocytochemistry (LH-RH, leuenkephalin, and ACTH) of the fibers and cell types. Bilateral projections of the suprachiasmatic nucleus into the arcuate nucleus were found. The number of connections between the supraoptic nucleus and nuclei of the mediobasal hypothalamus was found to be greater than hitherto reported. A direct projection from the suprachiasmatic nucleus into the median eminence could not be demonstrated with the retrograde horseradish peroxidase and the Lucifer Yellow liposome technique. Intermediobasal hypothalamic connections are not only organized over the third ventricle but also ventrally through the median eminance. ACTH-like fibers penetrate the suprachiasmatic nucleus. These connections originate in the arcuate nucleus of the mediobasal hypothlamus. Leu-enkephalin was demonstrated within the center of the suprachiasmatic nucleus; LH-RH positive cells, however, surround the suprachiasmatic nucleus.

Adrenocorticotropic Hormone↗
PubMed1987

Properties of cultured suprachiasmatic nucleus cells.

A method to culture neurons from various hypothalamic brain area of young and fetal rats is described. Hypothalamic slabs will survive for several months, and they are able to make interslab connections. Identification of the cultured cells was done by means of immunocytochemical and Lucifer Yellow liposome techniques.

Animals↗
PubMed1986

The development of longitudinal patterns in the rabbit cerebellum.

Reconstruction of several AChE series (from day E 18 after conception till after birth and in maturity) demonstrate that reaction products are localized in alternating positive and negative longitudinal strips. Till day E 26 the AChE activity is topographically related to certain Purkinje cell (P-cell) clusters and located around P-cells. At day E 24 till day E 26 AChE activity shirts into the marginal layer. At day E 28 AChE activity is present at the P-cell layer, around P-Cell somata and their dendrites. The longitudinal band pattern is still present at this age. Around birth AChE activity shifts into the granular layer, constituting a longitudinal AChE pattern. The changes in the localization of AChE are first observed in the anterior lobe and occur later in the posterior lobe vermis and hemispheres. At maturity the longitudinal AChE activity has disappeared from the P-cell layer, but a longitudinal pattern remains present in the granular layer of lobules VIII, IX, X. High AChE activity is found in the granular layer of flocculus and paraflocculus. Within the molecular layer AChE positive Golgi-cells can be demonstrated.

Acetylcholinesterase↗
PubMed1986

The neurotoxic effect of monosodium glutamate (MSG) on the retinal ganglion cells of the albino rat.

Monosodium glutamate (MSG) administered postnatally to the albino rat causes extensive destruction of the retina. This MSG effect does not result in complete blindness. Ganglion cells surviving the MSG treatment are healthy and functional. Using retrogradely transported HRP and Nissl staining in whole mounted retinas, it was found that the ganglion cells left after MSG treatment are not smaller than those in controls, that these cells do not belong to one cell size group, and that no cells size group is selectively missed. The results explain why photic entrainment of MSG treated animals is still possible.

Animals↗