AN AUTORADIOGRAPHIC STUDY OF ENDOCRINE ACTIVITY FOLLOWING FRONTAL GANGLIONECTOMY IN VIRGIN FEMALES OF MELANOPLUS SANGUINIPES (ORTHOPTERA: ACRIDIDAE)

1970 ◽  
Vol 102 (9) ◽  
pp. 1083-1088 ◽  
Author(s):  
C. Gillott ◽  
G. S. Dogra ◽  
Al B. Ewen
Keyword(s):  
Type A ◽  
Autoradiographic Study ◽  
Neurosecretory Cells ◽  
Corpus Allatum ◽  
Melanoplus Sanguinipes ◽  
Endocrine Activity ◽  
Frontal Ganglion

AbstractThe synthetic ability of type-A neurosecretory cells (NSC) and corpus allatum (CA) was investigated autoradiographically in both normal virgin females and those from which the frontal ganglion had been removed. Incorporation of 3H-cystine and 3H-uridine into the NSC was significantly lower in frontal ganglionectomized insects than in controls. There appeared to be no relationship between the level of isotope uptake and the amount of stainable material in the NSC. Ability of the CA to incorporate 3H-uridine seemed unaffected by the operation.

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.

Endocrine activity during caste differentiation in Zootermopsis angusticollis Hagen (Isoptera): a morphometric and autoradiographic study

1975 ◽  
Vol 53 (11) ◽  
pp. 1690-1700 ◽  
Author(s):  
Chih-Ming Yin ◽  
Cedric Gillott
Keyword(s):  
Autoradiographic Study ◽  
Neurosecretory Cells ◽  
Caste Differentiation ◽  
Corpora Allata ◽  
Synthetic Activity ◽  
Cell Diameter ◽  
Endocrine Control ◽  
Endocrine Activity ◽  
Zootermopsis Angusticollis ◽  
Primary Reproductives

The diameters of the median neurosecretory cells (MNC) and their nuclei, and the volumes of the corpora cardiaca (CC) and corpora allata (CA) were measured in termites (Zootermopsis angusticollis) of differing age, sex, and caste. The synthetic activities of the MNC and CA were estimated autoradiographically.No significant differences in the diameters of the MNC and their nuclei were observed between insects of differing age, sex, and caste, with the exception of primary reproductives whose MNC are significantly larger than those of larvae of the same instar. The six types of MNC distinguishable histologically differ in their nuclear diameter : cell diameter ratios and in their rates of [3H]uridine and [3H]cystine incorporation.The volumes and (or) synthetic activities of the CA change markedly during the differentiation of reproductives and soldiers. The CA of recently molted primary and supplementary reproductives are several times larger than those of larvae and nymphs of the previous instar, yet their synthetic activity remains low. In contrast, the CA of presoldiers and soldiers are only slightly larger than those of previous instar larvae, but show high synthetic activity. The data are discussed in terms of the endocrine control of caste differentiation.

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.

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 --·--

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.

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