Membrane retrieval at neurosecretory axon endings

Nature ◽  
1976 ◽  
Vol 261 (5562) ◽  
pp. 723-725 ◽  
Author(s):  
J. J. NORDMANN ◽  
J. F. MORRIS
Keyword(s):  
Neurosecretory Axon

Insect peripheral nerves: accessibility of neurohaemal regions to lanthanum

1975 ◽  
Vol 18 (1) ◽  
pp. 179-197 ◽  
Author(s):  
N.J. Lane ◽  
R.A. Leslie ◽  
L.S. Swales
Keyword(s):  
Blood Brain Barrier ◽  
Peripheral Nerves ◽  
Rhodnius Prolixus ◽  
Ionic Lanthanum ◽  
Neurosecretory Axon ◽  
Thin Part ◽  
Free Media ◽  
Exogenous Substances

During incubation in vivo, exogenously applied ionic lanthanum comes to surround the numerous neurosecretory terminals which are found lying within or immediately beneath the acellular neural lamella ensheathing the nerves from fifth instar and adult specimens of Rhodnius prolixus. The lanthanum does not penetrate beyond the cellular perineurium, which completely surrounds the non-neurosecretory axons in these nerves and constitutes a form of ‘blood-brain barrier’. In some cases, however, lanthanum is found in the vicinity of a neurosecretory axon lying beneath the perineurium, where it can be assumed to have leaked in from the neurosecretory terminal lying free in the neural lamella. When nerves are incubated in calcium-free media, regions with an attenuated perineurium become ‘leaky’, in that lanthanum is found lying in those extracellular spaces between axons and glia which lie immediately below the thin part of the perineurial layer. Bathing solutions made slightly hyperosmotic to the haemolymph with sucrose have no apparent disruptive effects on the barrier. When the tissues are incubated in more hypertonic solutions, the perineurial barrier becomes ‘leaky’ throughout, and tracer pervades beyond its cells into all the intercellular spaced between glia and axons. The possible role of the zonulae occludentes in both the maintenance of the perineurial barrier and in the formation of interglial occlusions to local penetration of exogenous substances is considered.

Fine Structure of the Crayfish Sinus Gland

1967 ◽  
Vol 25 ◽  
pp. 12-13
Author(s):  
Ann Heffington Bunt ◽  
Ebert A. Ashby
Keyword(s):  
Procambarus Clarkii ◽  
Retinal Pigment ◽  
Secretory Product ◽  
Neurosecretory Granules ◽  
Sinus Gland ◽  
Land Crab ◽  
Blood Sinus ◽  
Axon Terminals ◽  
Neurosecretory Axon ◽  
Neurosecretory Axon Terminals

The sinus gland of the crayfish, Procambarus clarkii, is located on the dorsum of the eyestalk, just beneath the exoskeleton and adjacent to the medullae interna and externa optic ganglia. It functions to secrete a variety of proteinaceous hormones, including the erythrophore concentrating hormone, melanophore dispersing hormone, molt inhibiting hormone, diabetogenic hormone, distal retinal pigment hormone, and ovary inhibiting hormone.The gland is composed of numerous neurosecretory axon terminals clustered about a branching blood sinus. The neurosecretory axons arise from cells lying some distance away from the sinus gland, in the medulla terminal is X-organ, the brain, and possibly the thoracic ganglion. The hormones are manufactured in the perikarya of these cells and transported through the axons to their terminals in the sinus gland for storage and release into the blood sinus.Small, electron dense spherules within the axons contain the hormone secretory product. These neurosecretory granules are very similar in morphology to those reported in the sinus glands of the dwarf crayfish, Cambarellus shufeldti, the land crab, Gecarcinus lateralis, and the Mediterranean isopod, Sguilla mantis. The sinus glands of each of these crustaceans contain two size ranges of neurosecretory granules: 1500-2000A and 500-900A.

Magnocellular neurosecretory axon regeneration into rat intrahypothalamic optic nerve allografts

1989 ◽  
Vol 24 (2) ◽  
pp. 163-168 ◽  
Author(s):  
H.-D. Dellmann ◽  
L.-F. Lue ◽  
S. I. Bellin ◽  
M. Quassat
Keyword(s):  
Optic Nerve ◽  
Axon Regeneration ◽  
Neurosecretory Axon

scholarly journals Intrahypothalamically Transected Neurosecretory Axons do not Regenerate in the Absence of Glial Cells

1993 ◽  
Vol 4 (2) ◽  
pp. 127-137 ◽  
Author(s):  
H.-Dieter Dellmann ◽  
Jeanine Carithers
Keyword(s):  
Extracellular Matrix ◽  
Optic Nerve ◽  
Sciatic Nerve ◽  
Glial Cells ◽  
Basal Lamina ◽  
Axon Regeneration ◽  
Neural Lobe ◽  
Hypothalamic Area ◽  
Nerve Grafts ◽  
Neurosecretory Axon

Fifteen days after transection of the hypothalamo-neurohypophysial tract at the lateral retrochiasmatic hypothalamic area, neurosecretory axons had vigorously regenerated into transplants of explanted hypophysial neural lobe, to a lesser extent into sciatic nerve transplants, and least into optic nerve transplants. Regenerating axons were always closely associated with the specific glial cells of these grafts. When these glial cells were killed by cryotreatment prior to transplantation, neurosecretory axons did not regenerate into the abundant extracellular matrix of the transplants, including persisting basal lamina tubes in neural lobe and sciatic nerve grafts. The presence of viable glial cells is a prerequisite for neurosecretory axon regeneration.

The destination of the aged, nonreleasable neurohypophyseal peptides stored in the neural lobe is associated to the remodeling of the neurosecretory axon

2005 ◽  
Vol 68 (6) ◽  
pp. 347-359 ◽  
Author(s):  
Juan Krsulovic ◽  
Bruno Peruzzo ◽  
Genaro Alvial ◽  
Carlos R. Yulis ◽  
Esteban M. Rodríguez
Keyword(s):  
Neural Lobe ◽  
Neurosecretory Axon

Potassium-Induced Release of the Diuretic Hormones of Rhodnius Prolixus and Glossina Austeni: Ca Dependence, Time Course and Localization of Neurohaemal Areas

1974 ◽  
Vol 61 (1) ◽  
pp. 155-171 ◽  
Author(s):  
S. H. P. MADDRELL ◽  
J. D. GEE
Keyword(s):  
Time Course ◽  
Rhodnius Prolixus ◽  
Prolonged Treatment ◽  
Hormone Release ◽  
Diuretic Hormone ◽  
Glossina Austeni ◽  
Low Concentrations ◽  
Neurosecretory Axon ◽  
K Concentration ◽  
Neurohaemal Areas

1. Exposure of neurohaemal areas to solutions of elevated K concentration (above 40 mM) causes a maximal release of diuretic hormone in Rhodnius prolixus and Glossina austeni. 2. An involvement of Ca in hormone release is indicated by the reduction caused by low concentrations of this cation (below 2 mM) or by the presence of Mn. 3. During prolonged treatment with K-rich solutions the rate of hormone release is initially high, but then declines. This response parallels that for Ca entry into squid giant axons during maintained potassium depolarization and suggests that the rate of Ca entry controls the rate of hormone release. 4. Tetrodotoxin did not reduce the potassium-induced release of the hormone, suggesting that K acts directly on the neurosecretory axon endings in the neurohaemal areas.

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