Errata

1963 ◽  
Vol 40 (3) ◽  
pp. 403-403
Keyword(s):  
Protease Activity ◽  
Neurosecretory Cells ◽  
Corpus Allatum

‘Influence of neurosecretory cells and of corpus allatum on intestinal protease activity in the adult Calliphora erythrocephalaMeig’. Page 302, line 18 for 10°C. read -10°C. Page 306, explanation to Fig. 20 for --•--•--, read --·--

Influence of Neurosecretory Cells and of Corpus Allatum on Intestinal Protease Activity in the Adult Calliphora Erythrocephala MEIG

1963 ◽  
Vol 40 (2) ◽  
pp. 301-321
Author(s):  
ELLEN THOMSEN ◽  
IB MØLLER
Keyword(s):  
Protein Synthesis ◽  
Protease Activity ◽  
Proteolytic Enzymes ◽  
Specific Protein ◽  
Neurosecretory Cells ◽  
Corpus Allatum ◽  
Minor Effect ◽  
Calliphora Erythrocephala ◽  
Sugar Water ◽  
The Mean

1. The protease activity of the adult Calliphora female measured on the first 5 days after emergence was found to be highly influenced by the diet, the activity of females fed on sugar, water and meat (meat-flies) being much higher than that of females fed only on sugar and water (sugar-flies). 2. The development of the enzyme(s) was found to be controlled by the medial neurosecretory cells (m.n.c.), the mean protease activity of females deprived of their m.n.c. only amounting to one-quarter to one-third of the maximum values for the meat-flies. 3. Implantation of corpora cardiaca-allata (presumably containing m.n.c. hormone) into females without m.n.c. raised the protease activity of these significantly, showing that the influence of the implanted organs must be hormonal. 4. The corpus allatum was found to have a certain, if minor, effect on the protease activity. 5. It is concluded that in Calliphora the eating of meat exerts its effect on the production of protease mainly indirectly by causing liberation of m.n.c. hormone into the blood. 6. As proteases are themselves proteins, the effect of the m.n.c. hormone on the production of proteolytic enzymes by the gut cells must be regarded as an effect on the specific protein synthesis of these cells. There is some evidence that the m.n.c. hormone might be involved in the regulation of protein synthesis in general.

An Autoradiographic Study of Neurosecretory Cell Activity of Allatectomized Females of the Grasshopper, Melanoplus sanguinipes (Fab.)

1975 ◽  
Vol 30 (7-8) ◽  
pp. 511-515
Author(s):  
G. S. Dogra
Keyword(s):  
Neurosecretory Cell ◽  
Cell Activity ◽  
Secretory Activity ◽  
Autoradiographic Study ◽  
Neurosecretory Cells ◽  
Corpus Allatum ◽  
High Uptake ◽  
Melanoplus Sanguinipes ◽  
Gradual Accumulation ◽  
Activity Cycles

Abstract Neurosecretory cell activity was studied autoradiographically in the allatectomized females of Melanoplus sanguinipes on every alternate day and in the normal control females on every fourth day for a period of 34 days. Experimental females exhibited five activity cycles against the two recorded by the control females. There was a comparatively high uptake of [3H] cystine by the neurosecretory cells of the experimental females on a particular day. During the first 12 days there was no accumulation of stainable colloid in their system. By the 24th day there was a slow and gradual accumulation of the colloids in the cells and their tracts so that on 34th day the system was well loaded with these colloids. In control females there was good accumulation of the stainable material during the first 12 days and then it declined so that 20 day old females had very little material in their system. This was followed by a massive accumulation of the stained colloids by 32nd day. The uptake of [3H] uridine was very high in the nerve-regenerate of the experimental females, and there were six cycles of secretory activity during the period of experimentation. The corpus allatum of control females, like their neurosecretory cells, exhibited only two activity cycles. Since the activity of the neurosecretory cells parallels the RNA synthesis in the nerve-regenerate, it is postulated that the neurosecretory cells produce factors for nerve-regeneration. On the basis of high uptake of isotopes by the neurosecretory cells of those allatectomized females in which the oocytes were mature it is suggested that the hormone (s) produced by the neurosecretory cells are perhaps responsible for oocyte maturation in these allatectomized females.

THE NEUROENDOCRINE ORGANS OF LARVAE OF NEODIPRION LECONTEI, N. SWAINEI, AND DIPRION HERCYNIAE (HYMENOPTERA: DIPRIONIDAE)

1973 ◽  
Vol 105 (5) ◽  
pp. 725-731 ◽  
Author(s):  
C. F. Hinks
Keyword(s):  
Neurosecretory Cells ◽  
Corpus Allatum ◽  
Single Pair ◽  
Corpora Cardiaca ◽  
Neodiprion Lecontei ◽  
Lateral Organs ◽  
Segmental Nerve ◽  
Endocrine Organs ◽  
Neuroendocrine Organs ◽  
The Brain

AbstractLarvae and eonymphs of the diprionid sawflies Neodiprion lecontei (Fitch), Neodiprion swainei Midd., and Diprion hercyniae (Htg.) were dissected and stained to demonstrate the nervous system and endocrine organs. Morphologically and anatomically the endocrine organs in both larvae and eonymphs of all three species are very similar. The cephalic structures comprise lateral and medial neurosecretory cells in the brain which discharge their secretions through a single pair of nerves (NCC) to the corpora cardiaca. The NCC divide before they enter the corpora cardiaca sending a branch to the corresponding corpus allatum. No other nervous connections with these organs are apparent.Paired neurohaemal organs occur in each thoracic segment, forming distinct dilations on slender nerves arising from the ventral cord connectives. They receive secretions from groups of lateral neurosecretory cells in the thoracic ganglia.Each abdominal ganglion has three neurohaemal organs associated with it, a single small spherical structure antero-medially, and paired lateral organs of a diffuse structure, overlying the base of each segmental nerve. They are less conspicuous than the thoracic organs and have different staining properties.

Humoral Regulation of the Cerebral Neurosecretory System of Rhodnius Prolixus (Stal.) During Growth and Moulting

1973 ◽  
Vol 58 (1) ◽  
pp. 177-187
Author(s):  
C. G. H. STEEL
Keyword(s):  
Critical Period ◽  
Endocrine System ◽  
Feedback Regulation ◽  
Neurosecretory Cells ◽  
Corpus Allatum ◽  
Neurosecretory System ◽  
Neurosecretory Material ◽  
Before And After ◽  
Cytological Changes ◽  
The Brain

1. In normal fifth instar Rhodnius the cytological changes occurring in the medial neurosecretory cells (MNC) of the brain are very different before and after the ‘critical period’ for decapitation. 2. When a decapitated insect which has reached the ‘critical period’ (8 days after feeding) is joined in parabiosis to an insect with an intact cerebral endocrine system and which has not yet reached the ‘critical period’ (1 day after feeding) the MNC of the younger insect are induced to switch over from their normal sequence of cytological changes to those characteristic of the older insect. The induced changes do not occur in normal insects of the same age or in insects joined in parabiosis to others of the same age. 3. The nature of the changes indicates that release of stainable neurosecretory material is inhibited and its synthesis stimulated by the older insect. It is inferred that the haemolymph of insects which have reached the ‘critical period’ contains a factor which induces in the MNC an inhibition of release and a stimulation of synthesis. These are the events which occur in the MNC of normal insects at the critical period. 4. Considerable circumstantial evidence suggests that the factor is ecdysone. It may act either directly on the brain or on the corpus allatum. Its contribution to a feedback regulation of the endocrine system controlling growth and moulting is discussed.

Architecture of Cerebral Neurosecretory Cell Systems in the Silkworm Bombyx Mori

1991 ◽  
Vol 161 (1) ◽  
pp. 217-237
Author(s):  
TOSHIO ICHIKAWA
Keyword(s):  
Bombyx Mori ◽  
Nerve Cord ◽  
Action Potentials ◽  
Lucifer Yellow ◽  
Neurosecretory Cells ◽  
Corpus Allatum ◽  
Cell Group ◽  
Neurosecretory Material ◽  
Larval Brain ◽  
Dendritic Branches

Anatomical and physiological characteristics of putative neurosecretory cells (NSCs) in the medial and lateral areas of the larval brain of Bombyx mori, identifiable by the opalescent appearance of their somata, were examined by means of intracellular recording and staining. Intracellular injection of Lucifer Yellow revealed that the medial cell group consisted of at least six subgroups of cells distinguishable by the geometry of their dendritic branches. Five subgroups of cells project axons to the contralateral corpus allatum (CA) or to the corpus cardiacum (CC). The remaining subgroup sends an axon to the ipsilateral ventral nerve cord. Three subgroups of cells were identified in the lateral group, projecting axons to the ipsilateral CC, to the CA or to the contralateral CA. Large and prolonged action potentials, similar to those recorded in some neurosecretory systems, were recorded from these medial and lateral cells. However, two pairs of medial cells containing paraldehyde-fuchsin-positive (neurosecretory) material and with axons extending to the contralateral nerve cord had action potentials of a short duration, more typical of non-NSCs such as tritocerebral cells innervating the stomodeal dilator muscles via the CC.

THE CORPUS ALLATUM AND OÖCYTE MATURATION IN ADELPHOCORIS LINEOLATUS (GOEZE) (HEMIPTERA: MIRIDAE)

1966 ◽  
Vol 44 (4) ◽  
pp. 719-727 ◽  
Author(s):  
A. B. Ewen
Keyword(s):  
Central Nervous System ◽  
Neurosecretory Cells ◽  
Corpus Allatum ◽  
Corpora Allata ◽  
Oocyte Growth ◽  
Egg Maturation ◽  
Adelphocoris Lineolatus ◽  
Histological Appearance ◽  
The Central Nervous System ◽  
Anatomical Connection

The corpus allatum undergoes marked changes in volume and histological appearance during egg maturation in the adult female of Adelphacoris lineolatus (Goeze). The allatum is very active just before yolk is deposited in the developing oöcytes, but activity declines rapidly at oviposition. This activity in the corpus allatum cannot be correlated with cyclical activity in the cerebral neurosecretory cells. Experiments involving removal of the corpus allatum show that the gland is necessary for oöcyte growth. Implantation of active corpora allata into allatectomized females will not restore egg maturation, and the implanted glands lose their secretory ability. It seems that the corpus allatum in this insect must retain anatomical connection with the central nervous system to produce its hormone.

The Corpus Allatum and Oogenesis in Rhodnius Prolixus (Stål.)

1972 ◽  
Vol 56 (1) ◽  
pp. 223-237
Author(s):  
G. E. PRATT ◽  
K. G. DAVEY
Keyword(s):  
Topical Application ◽  
Egg Production ◽  
Neurosecretory Cells ◽  
Corpus Allatum ◽  
Yolk Protein ◽  
Corpora Allata ◽  
Follicular Epithelium ◽  
High Doses ◽  
Dose Levels ◽  
Second Wave

1. Mated females lay more eggs than virgin females. They also oviposit earlier in the cycle, and at a higher rate, than virgins. 2. Mated females produce, slightly more than two oocytes per ovariole. Virgin females produce a little more than one oocyte per ovariole. The first wave of oogenesis proceeds at the same rate in mated and virgin females, whereas the second wave is inhibited in virgins. 3. The concentration of yolk protein in the haemolymph remains high for longer in virgins than in mated females. The inhibition of egg production during the second wave of oogenesis in virgins is thus not a consequence of a previous decline in yolk-protein titre. 4. Virgin females digest their blood meal more slowly than mated females. 5. The follicular epithelium of an oocyte in the second wave of oogenesis in a virgin shows sparsely scattered intercellular spaces, whereas that of an oocyte from the first wave exhibits the abundant spaces characteristic of a follicle from a mated female. 6. During the time when vitellogenesis is inhibited in virgins there is an accumulation of oocytes in the size range below that of activation. 7. The corpora allata of both mated and virgin females undergo a cycle of increase in size associated with the cycle of oogenesis. There are no differences which can be correlated with the differences in the activities of the ovaries of mated and virgin females. 8. Topical application of farnesyl methyl ether (FME) to decapitated mated females brings about egg development equivalent to that of virgin females. 9. Topical application of FME to virgin females results in the production of the number of eggs characteristic of mated females, but very high doses are necessary to achieve this. These dose levels also result in an increase in rate of oviposition. These effects of high doses of FME are abolished if the virgin females lack their neurosecretory cells. 10. It is concluded that the virgin inhibition of oogenesis results not from a deficiency of allatum hormone, but from the presence of an antigonadotropin released from ovaries which contain mature eggs.

Changes in the neurosecretory cells, corpus cardiacum and corpus allatum during pregnancy in Glossina austeni Newst. (Diptera, Glossinidae)

1974 ◽  
Vol 64 (2) ◽  
pp. 247-256 ◽  
Author(s):  
G. C. Ejezie ◽  
K. G. Davey
Keyword(s):  
Neurosecretory Cells ◽  
Corpus Allatum ◽  
Corpus Cardiacum ◽  
Pars Intercerebralis ◽  
Histological Sections ◽  
Glossina Austeni ◽  
Histological Appearance ◽  
Median Neurosecretory Cells ◽  
Cyclic Changes ◽  
Net Release

AbstractThe neurosecretory cells of the pars intercerebralis, the corpus cardiacum and the corpus allatum were examined in histological sections of Glossina austeni Newst. females fixed at daily intervals over the first two cycles of pregnancy. Two groups of neurosecretory cells corresponding to the lateral and median cells of other insects were recognised. The median neurosecretory cells were found to undergo cyclic changes of net synthesis and net release, which were correlated with ovulation and larviposition. The single ellipsoid corpus allatum undergoes cyclic changes in volume and histological appearance which are correlated with changes in the volume of the milk gland.

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