On the significance of the rostral process of bipolar neurosecretory cells in the caudal neurosecretory system of certain catfishes

Neurosecretory substance has been identified in the rostral process of bipolar neurosecretory cells of the caudal neurosecretory system in 4 Indian catfishes, using acid violet stain. The role of the rostral process in the transmission of the neurosecretory substance is discussed.     

A new neurosecretory system in fish,located in the gill region

Summary A peculiar neurosecretory system is reported in 6 teleost species;Clarias batrachus, Heteropneustes fossilis, Mystus seenghala, Ompak pabda, Glassogobius giuris andNotopterus notopterus. It is located in the gill region close to the pseudobranch or to the carotid labyrinth. The neurosecretory cells have been identified using stains specific for neurosecretion. The results are discussed in the light of the association of the neurosecretory system with the pseudobranch or the carotid labyrinth, and the airbreathing habit of these fishes.We are grateful to Prof. U.S. Srivastava for providing laboratory facilities and for encouragement. The work was financially supported by U.G.C. Research Project grant awarded to C.B.L.S., which is thankfully acknowledged. Thanks are due to M. Seal and Amarlata for technical help rendered.     

Neurosecretory system and storage of paraldehyde fuchsin positive neurosecretory material in the dorsal aorta in an earwig,Anisolabis annulipes Lucas (Dermaptera: Labiduridae)

Summary Each of the 2 groups of medial neurosecretory cells has 10–12 A and 2–3 B-cells. Each pars intercerebralis lateralis has 3–4 B-cells only. The 2 nervi corporis cardiaci I (NccI) join with the lateral wall of the aorta and Ncc II terminate in corpora cardiaca (Cc). Only 1 corpus allatum is present. The paraldehyde fuchsin positive neurosecretory material is stored in the dorsal aorta and not in the Cc which indicates the neurohaemal nature of the aorta.We are grateful to Prof. U.S. Srivastava for providing laboratory facilities and S.C.S.T. Uttar Pradesh for financial assistance.     

Optic lobe neurosecretory cells of an Indian spiderCryptophora sp. (Areinidae)

Summary In all the 3 pairs of optic lobes ofCryptophora sp. there are small groups of monopolar PF^– neurosecretory cells which take on a green colour by PF technique and red by Azan. Their function is unknown, but they may be involved with photoperiodically controlled activity rhythms.We wish to express our thanks to Prof. U.S. Srivastava for providing working facilities and valuable suggestions.     

Isolation of a neurosecretory substance which stimulates RNA synthesis in regenerating planarians.

An approach to the isolation of neurosecretory material from planarians is described. This material stimulated RNA synthesis, in a dose-dependent response, in regenerating Dugesia tigrina. The data support the concept that neurosecretion plays a key role in the process of regeneration in planarians.     

Isolation of a neurosecretory substance which stimulates RNA synthesis in regenerating planarians

Summary An approach to the isolation of neurosecretory material from planarians is described. This material stimulated RNA synthesis, in a dose-dependent response, in regeneratingDugesia tigrina. The data support the concept that neurosecretion plays a key role in the process of regeneration in planarians.Supported by funds from the National Research Council of Canada.     

An analytical study of the neurosecretory cells of the brain inPhilosamia ricini (Hutt.) (Lepidoptera: Saturniidae) during post-embryonic development

Summary A multiplicity of types of neurosecretory cell (NSC), and uniformity in the numbers occurring in medial, lateral, posterior and tritocerebral groups, have been observed inP. ricini. 3 types of cells A, B and C, with their subtypes (A-1, A-2, A-3; B-1, B-2; C-1 and C-2) have been reported. Only B-cells increase in numbers during post-embryonic development. Others (A and C) remain constant throughout development. Abnormal staining behaviour of A-cells has also been reported.Acknowledgements. We are grateful to Prof. S.D. Misra for the facilities and to the UGC, New Delhi, for sanctioning a grant No. F. 23-781/78 (SR II) dated 27.4.78 to Dr V.B. Awasthi, which is gratefully acknowledged.     

Effect of certain environmental factors on the cerebral neurosecretory cells of American cockroachPeriplaneta americana (L.)

Summary Under illumination, the cerebral neurosecretory cells (NSC) ofPeriplaneta americana were found to be depleted of neurosecretory material (NSM). It is suggested that, due to prolonged exposure to illumination, the synthesis of NSM was checked. The NSC were found densely packed with NSM after keeping the insects in total darkness. Clumping of NSC and their axons was brought about by 15 days of starvation. Diet played no significant role in the neurosecretory activity.We are thankful to Mr Fakhruddin, Saifia Educational Society for providing research facilities.     

The relation between capillaries and neurons in the caudal neurosecretory system of Pomatomus saltatrix.

The caudal neurosecretory system of Pomatomus saltatrix was examined. Particular interest was devoted to the perikarya of the neurosecretory cells. The majority of these cells were characterized by a close association with the capillary network. The cells appeared to ensheath the capillaries thus bringing the nucleus and perinuclear cytoplasm into close association with the capillaries.     

The relation between capillaries and neurons in the caudal neurosecretory system ofPomatomus saltatrix

Summary The caudal neurosecretory system ofPomatomus saltatrix was examined. Particular interest was devoted to the perikarya of the neurosecretory cells. The majority of these cells were characterized by a close association with the capillary network. The cells appeared to ensheath the capillaries thus bringing the nucleus and perinuclear cytoplasm into close association with the capillaries.Supported byA. D. Williams No. 3558 (505), Medical College of Virginia. The authors are grateful to Dr.H. R. Seibel for reading this report.     

Solubility of the neurosecretory products of Crepidula fornicata Phil., a prosobranch mullusk]

Study of solubility of neurosecretory products in Crepidula fornicata shows that the presence of ethanol in the fixative is incompatible with good fixation. This character permits the choice of a more effective extraction technique. An experimental study in organ culture shows that the action of differentiation of brain appears in the extract obtained by this method.     

The neurosecretory system of the octopus vena cava: A neurohemal organ

Summary Endings of about two million small neurones form a voluminous neuropil inside the vena cava of cephalopods, in direct contact with the blood. These nerve endings are filled with masses of typical neurosecretory granules. By immunocytochemistry we could distinguish three different populations of secretory endings in the vena cava neuropil ofOctopus vulgaris: 1) a population of endings which were immunoreactive with antibodies against the pentapeptide proctolin; 2) a population with oxytocin/vasopressin- and neurophysin-like immunoreactivity; 3) a population immunoreactive with antibodies which were raised against the molluscan cardioexcitatory peptide Phe-Met-Arg-Phe-amide, against -melanotropin, and against atriopeptin. Extracts of the octopus vena cava stimulated amplitude and frequency of the isolated octopus heart preparation. Similar effects were exerted by peptides with the C-terminal structure-Arg-Phe-amide. Recently, we could isolate and identify in vena cava extracts four peptides; Phe-Met-Arg-Phe-amide, Phe-Leu-Arg-Phe-amide, Ala-Phe-Leu-Arg-Phe-amide and Thr-Phe-Leu-Arg-Phe-amide. Other peptides have not yet been identified. The fact that the peptides against which the immunoreactive antibodies were raised affected, in different organisms, blood volume, blood pressure, renal function and heart contraction suggests that one of the main functions of the neurosecretory system of the vena cava is a hormonal control of circulation.     

The lateral neurosecretory cells and mating instinct in maleDysdercus koenigii (Hemiptera: Pyrrhocoridae)

Summary 5 pairs of median and 1 pair of lateral neurosecretory cell groups occur in the protocerebrum of maleDysdercus koenigii, a hemipteran pest on Hibiscus esculentus. The lateral neurosecretory cells (LNSC) are in a state of peak activity when the male engages itself in copulation. 24 h later, the LNSC are found to be inactive, but they again resume their activity 96 h after commencement of copulation. Such males soon start mating if they find another receptive female. It is believed that the secretion of LNSC in maleDysdercus koenigii is responsible for the onset of the urge for mating just as in female insects.     

Allatotropic activity of the median neurosecretory cells ofGalleria mellonella (lepidoptera) larval brain

Summary The brain allatotropic hormone (ATTH) is released inGalleria mellonella from the Median neurosecretory cells located in the pars intercerebralis. These cells show the ability to elicit supernumerary larval molts upon implantation into sensitive host larvae, and the ability to in vitro stimulate the juvenile hormone synthesis in corpora cardiaca-corpora allata glands ofG. mellonella.11 November 1986Acknowledgments. I am greatly indebted to Wesleyan University (Connecticut, USA) for supporting this study.     

Identification of actin microfilaments in the neurosecretory axons of rat neural lobe]

Incubation of rat neural lobes with heavy meromyosin (HMM) after prolonged glycerination, induced characteristic arrowhead decoration of a number of microfilaments at different levels of the neurosecretory axons. In non terminal sections of axons the labelled microfilaments showed preferential relationships with microtubules in addition to occasional contacts with the axolemma and various axonal organelles. In axonal endings, they were mainly associated to microvesicles and appeared to be anchored on the axolemma facing the perivascular space at the level of membranous densifications.     

Neurosecretory cells of the globuli I and the protocephalic neurosecretory pathway of the myriapods, diplodods. Preliminary observations on the Polydesmida, Platyrrhacidae, the Nematophora Lysiopetalidae, the Spirostreptida and the Spirobolida]

The Diplopods studied by the author and more particularly Platyrrhacidae, Lysiopetalidae, Spirostreptida and Spirobolida, show neurosecretory cells near the globuli I. The whole of his observations induces the author to admit a structural plan common to all the Diplopods: neurosecretory cells of globuli I--(NOG) nerve--neurohemal organ (Gabe's organ). Moreover he makes an attempt to compare his observations with those concerning another group of Myriapods: the Chilopods.     

Some remarks concerning staining methods for neurosecretory products in insects

Summary Insect neurosecretory cells show great diversity and respond differently to reportedly homologous stains, including Victoria blue, chrome hematoxylin-phloxin and paraldehyde fuchsin. Apart from this diversity, it is shown on a phasmidClitumnus and a bugRoscius, that the mode of application of technics have a great influence upon the staining properties of the cells.Dedicated to Professor Dr M. Gersch's on the occasion of his 70th birthday.     

Demonstration of acidophilic neurosecretory cells in Crepidula fornicata Phil. (Mollusca, Gasteropoda, Prosobranchia) using the fluorescent dye, Geranine G]

The Fluorochrome Geranine G binds to acidophilic neurosecretory cells and produces red orange fluorescence. Chromolipids and pigments show green fluorescence. This method is easy and sensitive. Fluorescence fading during irradiation is low.     

Neurosecretion and hydroelectrolytic regulation in Artemia salina (author's transl)]

The activity of Artemia protocerebral median neurosecretory cells is stimulated when animals are grown in media whose tonicity is lower than that of sea weater. The substance liberated by these cells could regulate the tonicity of the internal medium.     

Effects of precocene II and juvenile hormone III on the activity of neurosecretory A-cells inOncopeltus fasciatus

Summary Application of precocene II, topically or by contact method, appears to inhibit the synthetic activity of neurosecretory A-cells of the pars intercerebralis ofOncopeltus fasciatus. Treatment of precocene-treated insects with JH III apparently stimulates the secretory activity of these cells.Supported by National Research Council of Canada grant No. A4669.We thank Dr G. B. Staal, Zoecon Corporation, Palo Alto, California, for the gift of precocene II.