Synchronized neuronal networks: the GnRH system.

Abstract:

:The anatomical substrate for coordinated release from the dispersed gonadotropin-releasing hormone (GnRH) neuronal population remains obscure. There is physiological evidence that the GnRH hormone itself has a role in tonic inhibition or modulation of GnRH function. This has led to the hypothesis that there is an ultrashort negative feedback mechanism subserved by axon collaterals acting back on the GnRH neurons. Recent ultrastructural studies have revealed GnRH synapses on GnRH neurons and their processes. Furthermore, there are alterations in the frequency of these synapses with the age and hormonal condition of the animal. Another candidate for coordination of neuronal activity for which there is some evidence in the magnocellular system, is the gap junction. Recently, physiological and anatomical evidence for gap junctional modifications among an immortalized GnRH-secreting cell line (GT1) has been reported. However, at present there is no immunocytochemical or ultrastructural evidence for gap junctions between GnRH neurons. A third and highly unorthodox anatomical relationship between (among) these cells has been suggested by serial ultrastructural reconstructions of pairs of GnRH neurons in close association. In some regions, GnRH neuronal processes can be seen to extend from each member of a pair of GnRH neurons. These meet and merge, forming an intercellular bridge. This phenomenon has been observed in several pairs of GnRH neurons in rat and monkey. The important caveat in making these observations is that techniques employed to demonstrate sites of antigenicity can severely compromise the ultrastructural integrity of membrane components. For this reason, further verification of the existence of intercellular bridges is being pursued. Should their existence be confirmed, they would be prime candidates for the coordination of secretory events among the scattered GnRH neuronal population.

journal_name

Microsc Res Tech

authors

Witkin JW

doi

10.1002/(SICI)1097-0029(19990101)44:1<11::AID-JEMT

subject

Has Abstract

pub_date

1999-01-01 00:00:00

pages

11-8

issue

1

eissn

1059-910X

issn

1097-0029

pii

10.1002/(SICI)1097-0029(19990101)44:1<11::AID-JEMT

journal_volume

44

pub_type

杂志文章,评审
  • Plasticity of retinal ribbon synapses.

    abstract::Ribbon synapses differ from conventional chemical synapses in that they contain, within the cloud of synaptic vesicles (SV's), a specialized synaptic body, most often termed synaptic ribbon (SR). This body assumes various forms. Reconstructions reveal that what appear as rod- or ribbon-like profiles in sections are in...

    journal_title:Microscopy research and technique

    pub_type: 杂志文章,评审

    doi:10.1002/(SICI)1097-0029(19961215)35:6<472::AID-JEM

    authors: Vollrath L,Spiwoks-Becker I

    更新日期:1996-12-15 00:00:00

  • From oogonia to mature oocytes: inactivation of the maternal centrosome in humans.

    abstract::The fine structure of human oogonia and growing oocytes has been reviewed in fetal and adult ovaries. Preovulatory maturation and the ultrastructure of stimulated oocytes from the germinal vesicle (GV) stage to metaphase II (MII) stage are also documented. Oogonia have large nuclei, scanty cytoplasm with complex mitoc...

    journal_title:Microscopy research and technique

    pub_type: 杂志文章,评审

    doi:10.1002/jemt.20299

    authors: Sathananthan AH,Selvaraj K,Girijashankar ML,Ganesh V,Selvaraj P,Trounson AO

    更新日期:2006-06-01 00:00:00

  • Introduction to olfactory neuroepithelium.

    abstract::Among the five senses, the sense of smell (olfaction) is the most sensitive and emotional window on the outside world (Stern and Marx, 1999). The olfactory system recognizes and discriminates myriad odorants of diverse molecular structures. What makes the olfactory system so specific and sensitive? OE harboring the ol...

    journal_title:Microscopy research and technique

    pub_type: 杂志文章

    doi:10.1002/jemt.10130

    authors: Nibu K

    更新日期:2002-08-01 00:00:00

  • Immunocytochemical localization of adenylyl cyclase in human myometrium.

    abstract::The enzyme adenylyl cyclase (AC) plays a pivotal role in smooth muscle relaxation. Biochemical evidence suggests that AC is predominantly located in the outer layers of the myometrium; however, neither immunocytochemical nor histochemical studies have been undertaken to demonstrate the specific cellular distribution o...

    journal_title:Microscopy research and technique

    pub_type: 杂志文章

    doi:10.1002/(SICI)1097-0029(19980301)40:6<488::AID-JEM

    authors: Richards PD,Tiltman AJ,Richards PA

    更新日期:1998-03-15 00:00:00

  • Efficacy of different irrigant protocols and application systems on sealer penetration using a stepwise CLSM analysis.

    abstract::This study compared several irrigation protocols and application systems for sealer penetration into dentinal tubules. Single-rooted-human teeth were divided into 5 experimental groups (n = 15) and a control group (n = 5), according to final irrigation protocols: standard needle irrigation (SNI); Vibringe; Vibringe + ...

    journal_title:Microscopy research and technique

    pub_type: 杂志文章

    doi:10.1002/jemt.22944

    authors: Aksel H,Küçükkaya Eren S,Puralı N,Serper A,Azim AA

    更新日期:2017-12-01 00:00:00

  • Ultrastructural aspects of peptidergic modulation in the peripheral nervous system of Helix pomatia.

    abstract::The ultrastructural characteristics of peptidergic peripheral contacts in the snail, Helix pomatia, were investigated, with special attention to the innervation of the heart, buccal mass, and salivary gland by Mytilus inhibitory peptide-immunoreactive neurons. Following the application of correlative light- and electr...

    journal_title:Microscopy research and technique

    pub_type: 杂志文章

    doi:10.1002/1097-0029(20000615)49:6<534::AID-JEMT4>3.0

    authors: Elekes K

    更新日期:2000-06-15 00:00:00

  • In vitro sliding-driven morphological changes in representative esthetic NiTi archwire surfaces.

    abstract:OBJECTIVES:This study investigated the effects of sliding on the ultrastructure of three representative esthetic superelastic 0.014 inch nickel-titanium (NiTi) archwires. METHODS:Atomic force microscopy, scanning electron microscopy, and light microscopy were used to estimate the surface roughness of archwires and bra...

    journal_title:Microscopy research and technique

    pub_type: 杂志文章

    doi:10.1002/jemt.22557

    authors: Choi S,Park DJ,Kim KA,Park KH,Park HK,Park YG

    更新日期:2015-10-01 00:00:00

  • Confocal imaging of dendritic Ca2+ transients in hippocampal brain slices during simultaneous current- and voltage-clamp recording.

    abstract::Changes in the intracellular Ca2+ concentration ([Ca2+]i) within CA1 hippocampal pyramidal neurons were imaged using confocal laser scanning microscopy in conjunction with Ca(2+)-sensitive fluorescent indicators. The imaging was performed in thick hippocampal brain slices while simultaneously measuring or controlling ...

    journal_title:Microscopy research and technique

    pub_type: 杂志文章

    doi:10.1002/jemt.1070290404

    authors: Jaffe DB,Brown TH

    更新日期:1994-11-01 00:00:00

  • High-resolution X-ray CT for 3D petrography of ferruginous sandstone for an investigation of building stone decay.

    abstract::Diestian ferruginous sandstone has been used as the dominant building stone for monuments in the Hageland, a natural landscape in east-central Belgium. Like all rocks, this stone type is sensitive to weathering. Case hardening was observed in combination with blackening of the exterior parts of the dressed stones. To ...

    journal_title:Microscopy research and technique

    pub_type: 杂志文章

    doi:10.1002/jemt.20987

    authors: Cnudde V,Dewanckele J,Boone M,de Kock T,Boone M,Brabant L,Dusar M,de Ceukelaire M,de Clercq H,Hayen R,Jacobs P

    更新日期:2011-11-01 00:00:00

  • A negative contrast stain for ultra-thin frozen sections.

    abstract::Ultra-thin frozen sections are ideal substrates for immunolabelling in high resolution electron microscopy. However, visualization of subcellular structures is inferior to that obtained with corresponding plastic sections. Although negative staining is generally effective and even superior to positive staining, the ac...

    journal_title:Microscopy research and technique

    pub_type: 杂志文章

    doi:10.1002/jemt.1070290104

    authors: Himmelhoch S

    更新日期:1994-09-01 00:00:00

  • Immuno-detection of mRNA-binding protein complex in human cells under transmission electron microscopy.

    abstract::Transit from the nuclear complex to the cytoplasm through the nuclear pore complex permits modification of mRNA, including processing such as splicing, capping, and polyadenylation, etc. At each of these events, mRNA interacts with various proteins to form mRNA-protein complex. Visualizing the mRNA is crucial for unde...

    journal_title:Microscopy research and technique

    pub_type: 杂志文章

    doi:10.1002/jemt.23214

    authors: Ma Q,Tatsuno T,Nakamura Y,Izumi SI,Tomosugi N,Ishigaki Y

    更新日期:2019-06-01 00:00:00

  • Photochemically induced focal cochlear lesions in the guinea pig: I. DAB staining and SEM study.

    abstract::A photochemical reaction was used to produce focal microcirculation disorders in the guinea pig cochlea. Temporal bones were removed at various intervals between 5 minutes and 1 month after infusion of rose bengal (RB) and illumination. Infused but unilluminated contralateral cochleae served as controls. Dissected coc...

    journal_title:Microscopy research and technique

    pub_type: 杂志文章

    doi:10.1002/(SICI)1097-0029(19980515)41:4<323::AID-JEM

    authors: Gao J,Hoshino T,Iwasaki S,Wu R

    更新日期:1998-05-15 00:00:00

  • Effects of aerobic training, resistance training, or combined resistance-aerobic training on the left ventricular myocardium in a rat model.

    abstract::This study follows the left ventricular (LV) hypertrophy in rats undergoing aerobic training alone (A), resistance training alone (R), or combined resistance and aerobic training (RA) (usually referred as concurrent training) program. A sedentary control group (C) was included. LV remodeling was evaluated using electr...

    journal_title:Microscopy research and technique

    pub_type: 杂志文章

    doi:10.1002/jemt.22394

    authors: De Souza MR,Pimenta L,Pithon-Curi TC,Bucci M,Fontinele RG,De Souza RR

    更新日期:2014-09-01 00:00:00

  • Describing one generic and two new species record to the flora of Pakistan using LM and SEM methods.

    abstract::Common mulberry weed (Fatoua villosa (Thunb.) Nakai) and creeping amaranth (Amaranthus crassipes Schlecht) are reported for the first time in Pakistan's flora as these were not listed in any other literature nor identified before in Pakistan. Plants were found as a result of taxonomic studies performed in 2013 in Pesh...

    journal_title:Microscopy research and technique

    pub_type: 杂志文章

    doi:10.1002/jemt.23000

    authors: Jamshed S,Ullah A,Khan R,Hussain A

    更新日期:2018-05-01 00:00:00

  • Ultrastructural analysis of murine hippocampal neural progenitor cells in culture.

    abstract::Despite the great number of studies devoted to neural stem/progenitor cell biology, the ultrastructural characteristics of these cells in vitro have not been fully studied. To determine the fine structure of hippocampal neural progenitor cells (NPCs) in culture, mouse fetal hippocampi (E18) were extracted, dissected, ...

    journal_title:Microscopy research and technique

    pub_type: 杂志文章

    doi:10.1002/jemt.22454

    authors: Tsupykov O

    更新日期:2015-02-01 00:00:00

  • Environmental scanning electron microscope imaging examples related to particle analysis.

    abstract::This work provides examples of some of the imaging capabilities of environmental scanning electron microscopy applied to easily charged samples relevant to particle analysis. Environmental SEM (also referred to as high pressure or low vacuum SEM) can address uncoated samples that are known to be difficult to image. Mo...

    journal_title:Microscopy research and technique

    pub_type: 杂志文章

    doi:10.1002/jemt.1070250507

    authors: Wight SA,Zeissler CJ

    更新日期:1993-08-01 00:00:00

  • Pollen morphological assessment of specific selected species of district Sheikhupura, Punjab, Pakistan under LM and SEM.

    abstract::Around 30 pollen samples, 16 families and 25 genera that were gathered, identified and preserved from 6 different localities of District Sheikhupura. Light and scanning electron microscopy was done for all collected flora. Out of the total samples, 43% specie was identified as herbs, 23% as shrubs, and 33% were identi...

    journal_title:Microscopy research and technique

    pub_type: 杂志文章

    doi:10.1002/jemt.23656

    authors: Alam A,Shaheen S,Sarwar S,Jaffer M,Saba M,Hanif M,Sajjad S,Khan F

    更新日期:2020-12-31 00:00:00

  • Recent advances in insect olfaction, specifically regarding the morphology and sensory physiology of antennal sensilla of the female sphinx moth Manduca sexta.

    abstract::The antennal flagellum of female Manduca sexta bears eight sensillum types: two trichoid, two basiconic, one auriculate, two coeloconic, and one styliform complex sensilla. The first type of trichoid sensillum averages 34 microm in length and is innervated by two sensory cells. The second type averages 26 microm in le...

    journal_title:Microscopy research and technique

    pub_type: 杂志文章,评审

    doi:10.1002/jemt.1180

    authors: Shields VD,Hildebrand JG

    更新日期:2001-12-01 00:00:00

  • Ultrastructural neurobiology of the olfactory mucosa of the brown trout, Salmo trutta.

    abstract::This paper describes four investigations of the olfactory mucosa of the brown trout: 1) the ultrastructure of the olfactory mucosa as revealed by scanning (SEM), conventional transmission (TEM), and high voltage (HVEM) electron microscopy; 2) light and electron-microscopic investigations of retrograde transport of the...

    journal_title:Microscopy research and technique

    pub_type: 杂志文章

    doi:10.1002/jemt.1070230104

    authors: Moran DT,Rowley JC 3rd,Aiken GR,Jafek BW

    更新日期:1992-10-01 00:00:00

  • Peracetic acid as a single endodontic irrigant: effects on microhardness, roughness and erosion of root canal dentin.

    abstract::The aim was to assess the effects of 1% peracetic acid (PAA) as a single endodontic irrigant on microhardness, roughness, and erosion of root canal dentin, compared with 2.5% sodium hypochlorite (NaOCl) and with 2.5% NaOCl combined with 17% EDTA. Forty human, single-rooted tooth hemisections were submitted to Knoop mi...

    journal_title:Microscopy research and technique

    pub_type: 杂志文章

    doi:10.1002/jemt.23424

    authors: Keine KC,Kuga MC,Coaguila-Llerena H,Palma-Dibb RG,Faria G

    更新日期:2020-04-01 00:00:00

  • Combination of normal light and fluorescence microscopy for authentication of five Lonicera species flower buds.

    abstract::The flower buds of five Lonicera species, Lonicera japonica Thunb., L. macranthoides Hand.-Mazz., L. hypoglauca Miq., L. confusa DC. and L. fulvotomentosa Hsu et S.C. Cheng are confusable and usually utilized under the same name "Jinyinhua" in different areas for morphological similarity. Studies found that these five...

    journal_title:Microscopy research and technique

    pub_type: 杂志文章

    doi:10.1002/jemt.20882

    authors: Chu C,Liu HJ,Qi LW,Liu EH,Li P

    更新日期:2011-02-01 00:00:00

  • Immunocytochemical investigations of sodium channels along nodal and internodal portions of demyelinated axons.

    abstract::Voltage-gated sodium channels are largely localized to the nodes of Ranvier in myelinated axons, providing the physiological basis for saltatory conduction. Studies using antisodium channel antibodies have shown that along demyelinated axons sodium channels form new distributions. The nature of this changed distributi...

    journal_title:Microscopy research and technique

    pub_type: 杂志文章,评审

    doi:10.1002/(SICI)1097-0029(19960801)34:5<445::AID-JEM

    authors: England JD,Levinson SR,Shrager P

    更新日期:1996-08-01 00:00:00

  • Age-related ultrastructural features of the tongue of the rock pigeon Columba livia dakhlae in different three age stages (young, mature, and adult) captured from Egypt.

    abstract::This study represents the first attempt to describe the ultra-structural and histological features of different three age-stages (young, mature, and adult) of rock pigeon Columba livia dakhlae captured from Egypt. The elongated tongue with round lingual apex carried a lingual nail rostrally on lingual tip. The current...

    journal_title:Microscopy research and technique

    pub_type: 杂志文章

    doi:10.1002/jemt.23394

    authors: Abumandour MMA,Kandyel RM

    更新日期:2020-02-01 00:00:00

  • User-friendly semiautomated assembly of accurate image mosaics in microscopy.

    abstract::We present a semiautomated software solution to the problem of extending the lateral field of view of a classical microscope. The initial requirements are a set of overlapping images, along with their user-provided coarse mosaic. Our solution then refines this initial mosaic in a fully automatic fashion. We rely on a ...

    journal_title:Microscopy research and technique

    pub_type: 杂志文章

    doi:10.1002/jemt.20393

    authors: Thévenaz P,Unser M

    更新日期:2007-02-01 00:00:00

  • Intramandibular glands in different castes of leaf-cutting ant, Atta laevigata (Fr. Smith, 1858) (Formicidae: Attini).

    abstract::Intramandibular glands have been poorly studied in polymorphic ants, where the differences between castes were unsufficiently scrutinized. Leaf-cutting ants possess one of the most complex systems of communication and labor division, which is polymorphic well as age polyethism, and makes them an ideal model for the st...

    journal_title:Microscopy research and technique

    pub_type: 杂志文章

    doi:10.1002/jemt.22516

    authors: Martins LC,Della Lucia TM,Gonçalves WG,Delabie JH,Zanuncio JC,Serrão JE

    更新日期:2015-07-01 00:00:00

  • GFAP immunoreactivity and transcription in trigeminal and dental tissues of rats and transgenic GFP/GFAP mice.

    abstract::Sensory mechanisms in teeth are not well understood and may involve pulpal-neural interactions. Tooth cells that proliferate in vitro have polyclonal immunoreactivity (IR) for glial fibrillary acidic protein (GFAP), growth-associated protein (GAP-43), and vimentin, plus glial-like ion channels. Here, we analyzed GFAP-...

    journal_title:Microscopy research and technique

    pub_type: 杂志文章

    doi:10.1002/jemt.20130

    authors: Byers MR,Maeda T,Brown AM,Westenbroek RE

    更新日期:2004-12-01 00:00:00

  • Antennal sensilla of Apanteles cypris Nixon (Hymenoptera: Braconidae), a larval endoparasitoid of Cnaphalocrocis medinalis Guenée (Lepidoptera: Pyralidae).

    abstract::Apanteles cypris is an endoparasitoid of rice pest Cnaphalocrocis medinalis. To better understand its host location mechanism, we examined the external morphology of antennal sensilla of A. cypris via scanning electron microscopy. The antennae of male and female A. cypris were filiform in shape, which consist of scape...

    journal_title:Microscopy research and technique

    pub_type: 杂志文章

    doi:10.1002/jemt.21016

    authors: Zhou H,Wu WJ,Zhnag ZF,Zhnag Y

    更新日期:2011-12-01 00:00:00

  • Enhanced effects of nonisotopic hafnium chloride in methanol as a substitute for uranyl acetate in TEM contrast of ultrastructure of fungal and plant cells.

    abstract::This ultrastructural study showed that nonisotopic methanolic hafnium chloride and aqueous lead solution was an excellent new electron stain for enhancing TEM contrasts of fungal and plant cell structures. The ultrastructural definition provided by the new stain was often superior to that provided by conventional stai...

    journal_title:Microscopy research and technique

    pub_type: 杂志文章

    doi:10.1002/jemt.20964

    authors: Ikeda K,Inoue K,Kanematsu S,Horiuchi Y,Park P

    更新日期:2011-09-01 00:00:00

  • Effect of ultrasonic excitation on the porosity of glass ionomer cement: a scanning electron microscope evaluation.

    abstract:BACKGROUND:Ultrasonic excitation (US) was applied to glass ionomer cement (GIC) during early set time to increase the advantageous properties of this material. PURPOSE:The aim of this in vitro study was to assess the inner porosity of GIC after US. STUDY DESIGN:A total of 16 specimens, for each material, were prepare...

    journal_title:Microscopy research and technique

    pub_type: 杂志文章

    doi:10.1002/jemt.20873

    authors: Coldebella CR,Santos-Pinto L,Zuanon AC

    更新日期:2011-01-01 00:00:00

  • Presence and distribution of FMRFamide-like immunoreactivity in the cyprid of the barnacle Balanus amphitrite (Cirripedia, Crustacea).

    abstract::The presence and distribution of FMRFamide-like peptides (FLPs) in the cyprid larvae of the barnacle Balanus amphitrite were investigated using immunohistochemical methods. Barnacles are considered to be one of the most important constituents of animal fouling communities, and the cyprid stage is specialized for settl...

    journal_title:Microscopy research and technique

    pub_type: 杂志文章

    doi:10.1002/jemt.20649

    authors: Gallus L,Ferrando S,Bottaro M,Diaspro A,Girosi L,Faimali M,Ramoino P,Tagliafierro G

    更新日期:2009-02-01 00:00:00