Types Of Neurosecretory Cells Research Articles

Cytochemical characteristics of the neurosecretory cells ofCeylonocotyle scoliocoelium(Trematoda: Digenea)

Two types of neurosecretory cells (NSC), large alpha cells and small beta cells were detected on the basis of their size and characteristics as shown by aldehyde fuchsin and chrome haematoxylin-phloxin staining. A histochemical survey of the neurosecretory material indicates that it is a glycoprotein. Phosphatases and esterases present in NSC probably help in the transfer of metabolites and their hydrolysis and in the control of secretory material produced in a NSC, while SDH provides the necessary energy for the synthetic activity of the latter. The role of neurosecretion in governing the reproduction of this parasite is discussed.

Studies on the neurosecretion of thoracic ganglion in relation to reproduction of femaleMacrobrachium lanchesteri (de Man)

The changes in the histology of thoracic ganglion in females ofMacro-brachium lanchesteri, prior to spawning and post parturial moult, have been described. Based on the differences in size, cell inclusions and differential staining with CHP, four distinct types of neurosecretory cells have been identified in the ganglion. The activity of these cells has been correlated with the ovarian condition of the prawn and evidence for the elaboration of a gonad-stimulating hormone (GSH), by the ganglion has been derived. The, probable regulation of ovarian maturation during a normal ovarian cycle and that during the ovigerous condition ofM. lanchesteri have been illustrated.

Ultrastructural analysis of peptide-hormone release by exocytosis

The release of neuropeptides and other proteinaceous hormones by exocytosis was studied in some detail by means of tannic acid in combination with glutaraldehyde (TAGO-method). This method strongly enhances the electron density of extracellular proteins including exocytosed secretory products, and therefore facilitates visualization of the release process in qualitative and quantitative respects. This study included a variety of neurosecretory cell types in the CNS of the freshwater snail L. stagnalis, the storage and glandular lobes of the corpora cardiaca of the locust L. migratoria, and the posterior pituitary of the rat. In addition, peptide secreting cells in the anterior pituitary were examined. The cytochemical specificity of the TAGO-method as well as the significance of "frozen" contents of exocytosing secretory granules in mammotrophs and somatotrophs of the rat is discussed.

Changes in the neurosecretory cells of the freshwater snail, lymnaea acuminata induced by urea administration

The effect of urea injections on the cytomorphology of neurosecretory cells of the snail L. acuminata has been examined. Of the three types of neurosecretory cells (A, B and C) the changes were evident only in C cells from the parietal ganglia. 3 hr after 0.1 ml of 1 M urea plus 0.1 ml of I M glucose injection, the appearance of neurosecretory material (NSM) in the neurohaemal area without any change in C cell C : N (Cytoplasm: nuclear) ratio, was evident, whereas daily injection of urea plus glucose for three consecutive days induced a significant (P = 0.005) increment in C cell nuclear diameter and C : N value over equiosmole control (glucose) injections. This was accompanied by about 50% depletion of perikarya NSM intensity and the neurohaemal area was completely destitute of the NSM. The significance of the data is discussed.

Responses of the neurosecretory cells of the freshwater snail, Indoplanorbis exustus to hydrothermal stress

Changes in the neurosecretory cell cytology of I. exustus subjected to hypertonic saline (0.1 ml of 1.5%/snail) loading and thermal stress (35°C) for two hours, have been investigated. Of the two types of neurosecretory cells A and B that are present in the central nervous system (CNS) of I. exustus, striking changes were evident only in B cells. After both treatments, there was about 33% decline in NSM (Neurosecretory material) intensity. However, the nuclear diameter of B cells was significantly (P < 0.001) increased in the snails administrated with hypertonic saline unlike in those exposed to 35°C wherein significant (P < 0.005) decline was evident. The adaptive significance of the neuroendocrine system of I exustus is discussed in relation to hydrothermal stress.

A Light Microscopical Study of the Nervous System of Simocephalus Vetulus Schodler (Cladocera) With Special Reference To Neurosecretion

The neurosecretory system of Simocephalus vetulus Schodler was studied with the light microscope. On the basis of size, shape, distribution, and staining affinity four types of neurosecretory cells were described in the brain and two types of neurons were also described in the suboesophageal ganglion and circumoesophageal connectives. A minority of neurons in the brain respond to the paraldehyde fuchsin staining technique (PAF) but they differ from each other with respect to the degree of their staining affinity. PAF-positive neurons were not observed in the suboesophageal ganglion and circumoesophageal connectives. Furthermore, no neurohaemal organ was observed in the brain.

Immunocytochemical localization of hyperglycemic hormone (HGH) in the neurosecretory system of the eyestalk of the crayfishAstacu leptodactylus

Hyperglycemic hormone (HGH) from Astacus leptodactylus can be visualized by an immunocytochemical procedure using a specific antiserum against HGH and the peroxidase-anti-peroxidase (PAP) method. HGH containing cells are localized in the most distal portion of the x-organ in the medulla terminalis. Their cell diameter is about 47 +/- 7 micrometer; the nucleus measures about 22 +/- 2 micrometer. They form a subgroup of neurosecretory cell type 1, already described for the crayfish. A large amount of this HGH material is homogeneously stored in the sinus gland. A group of fibres in the x-organ - sinus gland - tractus can be followed, due to their positive reaction with the PAP-reagent.

Osmotic regulation and osmotically induced changes in the neurosecretory cells of the pulmonate snail Helisoma

Helisoma duryi and H. trivolvis are hyperosmotic regulators within a range from distilled water to 20% sea water (0.5–200 mosmol/L). Ultrastructurally three types of neurosecretory cells can be recognized in the visceral and left parietal ganglia. Type 1 and 2 cells correspond to the paraldehyde fuchsin (PAF) positive group 1 cells of visceral and medium sized parietal cells of left parietal ganglia. Type 3 cells are located in the visceral ganglion; they are PAF negative. Type 1 and 2 cells stain intensely with PAF in snails kept in distilled water but stain faintly in snails kept in isosmotic saline. Perikarya and axon endings of type 2 cells contain more granules and appear synthetically active when snails are kept in distilled water but less synthetically active when snails are kept in isosmotic saline. The response of type 1 cells is comparable with that of type 2 cells but less pronounced. The response of type 3 cells to media of different osmotic concentration is opposite to that found in type 2 cells. The possible roles of the cell types are discussed, and it is suggested that type 2 cells may be involved in diuresis.

Licht- und elektronenmikroskopische Untersuchung von neurosekretorischen Zellen im Gehirn der EintagsfliegeEphemera danicaMüll. (Ephemeroptera: Ephemeridae)

In the brains of the males the amount of stained secretory material was nearly constant during the last four instars. In the females a decrease in this neurosecretory product in the last nymphal and subimaginal stage could be observed, followed by an increase in the imagines. In the final nymphal stage four types of neurosecretory cells (nsc) were found in the medial protocerebral cell group, showing differences in shape, size, and the contents of the cytoplasm, especially of the secretory granules. In addition to the medial nsc, some cells in the frontal part of the brain and in the deutocerebrum are described. They contain electron-opaque granules and probably have a neurosecretory function. The secretory product of the medial nsc is transported along the axons of the nervus corporis cardiaci 1 (ncc1), an unpaired nerve tract on the ventral side of the brain. Leaving the brain the ncc1 immediately enters the corpus cardiacum. Connections between secretory granules and neurotubuli point to an important role for the neurotubuli in the transport of secretory material.

Neurosecretory products diversity in the pars intercerebralis of insects

The pars intercerebralis of insect brain, which has numerous physiological functions, contains more neurosecretory cell types than previously thought. There are 2 distinct types among the A cells. In addition to these cells, there are azocarminophilic cells, the C(r) cells, which are not apparent when using ‘classical’ staining methods.

Neurosecretory centers in the brain of adult gryllus Bimaculatus (de geer) (Orthoptera : Gryllidae)

Five types of neurosecretory cells, A, A′, B, C and D were recognized histologically as well as histochemically in the brain of adult Gryllus bimaculatus. They are distributed in 3 distinct neurosecretory centers: the median neurosecretory center which consists of an anterior and a posterior part; the lateral neurosecretory center and the tritocerebral neurosecretory center. Histochemical investigations demonstrate that lipids are abundant in A cells and tyrosine in C cells.

Les premiers stades de l'ovogenese et les variations de la neurosecretion cerebrale chez deux especes sympatriques Roscius elongatus stål et R. brazzavilliensis, Robert (Heteroptera : Pyrrhocoridae)

The comparative development of the different components of the germarium is described during 4th and 5th larval stages, in Roscius elongatuswhich does not diapauee and in R. brazzavilliensis, which diapauses. The first species shows 9 ovarian stages, the second 8 ; only the first 5 stages are common to both species. In R. elongatus, the growth of the egg is rapid and massive, while in R . brazzavilliensis it is slower and smaller. In R. elongatus, the meiosis begins at about the 4th stage. In R. brazzavilliensis, it takes place just before entering the diapause. The development of a peripheral epithelium around the tunica propria of the ovary is described. This may serve some purpose in the ovogenesis. At the level of the pars intercerebralis, there are 6 types of neurosecretory cells. The A' cells appear to control the meiosis, and the A and A' cells the transformation of the oocytes during previtellogenesis. The neurosecretory material of the A' cells is supposed to be similar to the brain hormone.

Mapping and ultrastructure of neurosecretory cells in the brain of Helix aspersa

1. 1. The brain of Helix aspersa contain three types of neurosecretory cells (DGC, LGC and YC), classified on the basis of the reaction of the neurosecretory products with Alcian Blue/Alcian Yellow technique. 2. 2. The monopolar DGC. and mono-, and bipolar LGC are Chrome-Haematoxylin positive, but the monopolar YC are CH-negative. 3. 3. The cells and their terminals contained granules of 1500–1800Å in diameter and electron lucent vesicles of similar diameter range. 4. 4. It is suggested that the neurosecretory products are released by diffusion, exocytosis or/and intracellular breakdown.

Histomorphological studies on the brain neurosecretory profile of Indian leech,Poecilobdella uiridis (Blanchard)

The histological scrutiny of the brain ofPoecilobdella viridis revealed two types (A and B) of neurosecretory cells, which are classifiedon the basis of size, shape and tinctorial characters. A cells are spheroid, rarely pyriform, with size (cell area) varying between 608 μ to 1701 μ. Their cytoplasmic granules take violet colouration with AF and deep red with Mallory’s triple stains. B cells are elongate or oblong with a size (cell area) ranging between 516 μto 831 μ. Their cytoplasmic granules are coloured blue to violet with AF and pink with Mallory’s triple stains. Neurosecretory material staining intensity of these cells is described light microscopically.

Morphology of the Neuroendocrine System of the Pink Bollworm1 and Histological Changes in the Neurosecretory Cells of the Brain during Induction, Maintenance, and Termination of Diapause, 3

Based on location and reactions to histological stains, 8 types of neurosecretory (NS) cells were observed in the brain of the pink bollworm, Pectinophora gossypiella (Saunders). In addition, NS cells were found in the frontal ganglion and corpus cardiacum. Substantial changes in staining intensity and size of perikarya and nuclei occurred in several NS cell types during maintenance and termination of diapause. Changes were most prominent in M-1 and M-2 cells, but most types showed larger amounts of stainable granular cytoplasmic inclusions during diapause.

Neurosecretory cells in the brain of Porcellio obsoletus (Isopoda: Oniscoidea)

In the brain of Porcellio obsoletus, 9 types of neurosecretory cells have been observed. Three of these are described here for the first time. These include a large neurosecretory cell with a short axon found in both deutocerebrum and tritocerebrum, and a small cell type with a short axon located in all regions of the brain. Two additional types were located only in the tritocerebrum. Both are large cells; one is elliptical and the other a vacuolated type of neurosecretory cell.

An ultrastruct study of the innervation of the musculature of the pond snail Lymnaea stagnalis (L.) with reference to peripheral neurosecretion.

The ultrastructure of nerve endings in the musculature of Lymnaea stagnalis was studied. Seventeen different types of axon ending were distinguished according to the size and morphology of the granules or vesicles they contain. Nine types of axon endings form neuromuscular synapses. Some of these types also form axo-somatic synapses on peripheral neurones. One axon may innervate several muscle cells. Furthermore more than one type of axon may innervate one muscle cell. One type of axon ending forms axo-axonic synapses on the presynaptic part of neuromuscular junctions. In the connective tissue near muscle cells seven types of free axon endings were found. These seem to be peripheral neurosecretory endings. Some of these are probably derived from known types of neurosecretory cells in the central nervous system, whereas others appear to originate from peripheral neuronal perikarya. Body wall muscles appear to be innervated by neuromusculatur synapses, whereas in the visceral musculature both neuromuscular junctions and free axon endings are found.

The diversity of neurosecretory cell types in the cave tick Ornithodoros tholozani.

Neurosecretory cells are arranged in 16 NSC centers in the different regions of the brain of O. tholozani. The component cells belong to 13 different types, of which five types are paraldehyde fuchsin positive and the remaining types are negative. Three of these cell types are here described for the first time. Some of these NSC show an affinity to certain localities inside the brain. Cells comprising a neurohaemal organ were found near the exit of the esophagus.

The Corpus Cardiacum Neurosecretory Cells of Schistocerca gregaria. Electron Microscopy of Resting and Secreting Cells

AbstractThe corpora cardiaca of Schistocerca consist of a neurohaemal part containing mainly extrinsic neurosecretory axons coming from the brain, and of a glandular part consisting mainly of intrinsic neurosecretory cells. Some extrinsic axons penetrate into the glandular region, and innervate intrinsic corpus cardiacum neurosecretory cells. The fine structure of the latter has been examined and related to other neurosecretory cell types. Secretion occurs by exocytosis. Omega‐profiles are more frequently observed in corpora cardiaca stimulated electrically or by acetylcholine than in the controls.

Ultrastructural studies on the secretory cycle of the neurosecretory cells and the formation of Herring bodies in the paraventricular nucleus of the rat.

The ultrastructure of the neurosecretory cells in the paraventricular nucleus of the normal male rat was studied by electron microscopy during various functional states. Four morphologically distinct types of neurosecretory cells were observed. It appears that they do not represent different classes of cells but different phases of secretory activity of a single cell type. The perikarya of the neurosecretory cells show a definite cycle of formation and transportation of secretory granules. We have designated the phases of this cycle as: (1) phase of synthesis, (2) phase of granule production, (3) phase of granule storage and (4) phase of granule transport. The neurosecretory granules appear to be moved in bulk into the axons, forming a large axonal swelling filled with granules as a result of one cycle in the neurosecretory process. Thus it may be postulated that a secretory cycle in the perikaryon of the neurosecretory cell seems to result in the formation of a Herring body in its axon, and that its content is then conveyed to the posterior pituitary.