Ovulation in Rhodnius prolixus Stal is induced by an extract of neurosecretory cells

1983 ◽  
Vol 61 (3) ◽  
pp. 684-686 ◽  
Author(s):  
F. L. Kriger ◽  
K. G. Davey
Keyword(s):  
Neurosecretory Cells ◽  
Rhodnius Prolixus ◽  
Pars Intercerebralis ◽  
Median Neurosecretory Cells ◽  
The Brain

The injection of an extract of 10 identified median neurosecretory cells from the pars intercerebralis into gravid mated females previously deprived of these cells by surgery induces ovulation and oviposition during the ensuring 24 h. Injection of an extract of ocellar nerves has no effect. These observations support the hypothesis that ovulation and oviposition are controlled by a myotropin released from neurosecretory cells in the brain.

Identified neurosecretory cells in the brain of female Rhodnius prolixus contain a myotropic peptide

1984 ◽  
Vol 62 (9) ◽  
pp. 1720-1723 ◽  
Author(s):  
F. L. Kriger ◽  
K. G. Davey
Keyword(s):  
Neurosecretory Cells ◽  
Rhodnius Prolixus ◽  
Pars Intercerebralis ◽  
Myotropic Activity ◽  
The Brain

Extracts of 10 identified neurosecretory cells in the pars intercerebralis exhibit myotropic activity when added to the medium bathing an isolated ovary of Rhodnius. The myotropic activity of the preparation, expressed as the power in joules per second, increases linearly over a 100-fold range of concentrations but is not further affected by higher concentrations. The activity in the extracts is stable after heating to 90 °C for 5 min, and is reduced by incubation with trypsin. Comparison with the effects of proctolin demonstrates that the neurosecretory myotropin is not proctolin.

Axon pathways of the intermediate neurosecretory cells in Culex tarsalis Coquillett (Diptera: Culicidae)

1973 ◽  
Vol 51 (3) ◽  
pp. 379-382 ◽  
Author(s):  
L. Burgess
Keyword(s):  
Neurosecretory Cells ◽  
Abdominal Ganglion ◽  
Culex Tarsalis ◽  
Pars Intercerebralis ◽  
Pass Through ◽  
Culiseta Inornata ◽  
The Brain

The axons of the intermediate neurosecretory cells in the brain of Culex tarsalis Coquillett larvae cross over in the pars intercerebralis, pass ventrolaterally through the protocerebrum, and then pass through the circumoesophageal connectives and the ventral nerve chain as far as the eighth abdominal ganglion. These axons possess branches in the region of juncture of the proto- and deuto-cerebrum, and in the suboesophageal, thoracic, and eighth abdominal ganglia; no branches were visible in the tritocerebrum or abdominal ganglia 1 to 7. The branches appear to terminate within the ganglia, usually near the neuropile boundary. The large ventral neurosecretory axons described in larvae of Culiseta inornata (Williston) by L. Burgess in 1971 are probably the axons of the intermediate neurosecretory cells of that mosquito.

scholarly journals The distribution of a CRF-like diuretic peptide in the blood-feeding bug Rhodnius prolixus

1999 ◽  
Vol 202 (15) ◽  
pp. 2017-2027 ◽  
Author(s):  
V.A. Te Brugge ◽  
S.M. Miksys ◽  
G.M. Coast ◽  
D.A. Schooley ◽  
I. Orchard
Keyword(s):  
Cyclic Amp ◽  
Malpighian Tubule ◽  
Immunogold Labelling ◽  
Blood Feeding ◽  
Neurosecretory Cells ◽  
Rhodnius Prolixus ◽  
Malpighian Tubules ◽  
Double Labelling ◽  
Neurohaemal Areas ◽  
The Brain

The blood-feeding bug Rhodnius prolixus ingests a large blood meal, and this is followed by a rapid diuresis to eliminate excess water and salt. Previous studies have demonstrated that serotonin and an unidentified peptide act as diuretic factors. In other insects, members of the corticotropin-releasing factor (CRF)-related peptide family have been shown to play a role in post-feeding diuresis. Using fluorescence immunohistochemistry and immunogold labelling with antibodies to the Locusta CRF-like diuretic hormone (Locusta-DH) and serotonin, we have mapped the distribution of neurones displaying these phenotypes in R. prolixus. Strong Locusta-DH-like immunoreactivity was found in numerous neurones of the central nervous system (CNS) and, in particular, in medial neurosecretory cells of the brain and in posterior lateral neurosecretory cells of the mesothoracic ganglionic mass (MTGM). Positively stained neurohaemal areas were found associated with the corpus cardiacum (CC) and on abdominal nerves 1 and 2. In addition, Locusta-DH-like immunoreactive nerve processes were found over the posterior midgut and hindgut. Double-labelling studies for Locusta-DH-like and serotonin-like immunoreactivity demonstrated some co-localisation in the CNS; however, no co-localisation was found in the medial neurosecretory cells of the brain, the posterior lateral neurosecretory cells of the MTGM or neurohaemal areas. To confirm the presence of a diuretic factor in the CC and abdominal nerves, extracts were tested in Malpighian tubule secretion assays and cyclic AMP assays. Extracts of the CC and abdominal nerves caused an increase in the rate of secretion and an increase in the level of cyclic AMP in the Malpighian tubules of fifth-instar R. prolixus. The presence of the peptide in neurohaemal terminals of the CC and abdominal nerves that are distinct from serotonin-containing terminals indicates that the peptide is capable of being released into the haemolymph and that this release can be independent of the release of serotonin.

Projection of FMRFamide-like neuropeptide-producing neurosecretory cells from silkworm brain into ventral nerve cord and retrocerebral complex

2012 ◽  
Vol 144 (3) ◽  
pp. 458-466 ◽  
Author(s):  
Bo Yong Kim ◽  
Hwa Young Song ◽  
Mi Young Kim ◽  
Pil Don Kang ◽  
Min Ho Cha ◽  
...  
Keyword(s):  
Juvenile Hormone ◽  
Bombyx Mori ◽  
Nerve Cord ◽  
Ventral Nerve Cord ◽  
Neurosecretory Cells ◽  
Single Pair ◽  
Corpus Cardiacum ◽  
Pars Intercerebralis ◽  
Median Region ◽  
The Brain

AbstractUsing immunostaining methodology, we traced the axonal projection of FMRFamide (Phe-Met-Arg-Phe-NH2)-like immunoreactive (LI) medial neurosecretory cells (MNCs) and lateral neurosecretory cells (LNCs) from the brain into the ventral nerve cord (VNC) and retrocerebral complex in Bombyx mori (L.) (Lepidoptera: Bombycidae). Of the seven pairs of FMRFamide-LI MNCs, one pair extended its axons from the brain pars intercerebralis into the VNC ipsilateral connective where they appeared to terminate. The axons of the remaining MNCs ran through decussation in the brain median region and contralateral nervi corporis cardiaci (NCC) I out of the brain, and eventually innervated the contralateral corpus cardiacum (CC). Axons from the single pair of FMRFamide-LI LNCs projected into the ipsilateral NCC II fused with NCC I without decussation in the brain, and finally terminated in the CC. These results suggest that transport of the FMRFamide-like neuropeptide from may be related to the modulation of functions such as gut contraction in MNCs terminating in the VNC, and regulation of production and/or secretion of specific hormones such as juvenile hormone in MNCs and LNCs terminating in the CC.

scholarly journals The feeding stimulus in Rhodnius prolixus is transmitted to the brain by a humoral factor

1995 ◽  
Vol 198 (5) ◽  
pp. 1087-1092
Author(s):  
H Mulye ◽  
K Davey
Keyword(s):  
Neurosecretory Cells ◽  
Rhodnius Prolixus ◽  
Spike Frequency ◽  
Dorsal Vessel ◽  
Similar Activity ◽  
Heat Stable ◽  
Action Potential Frequency ◽  
Neuroendocrine Axis ◽  
The Brain ◽  
Potential Frequency

Neurosecretory cells in the brain of Rhodnius prolixus are known to be the source of an ovulation hormone released at feeding. They were selected to test the hypothesis that feeding brings about the release of another hormone in the abdomen which is transported forward to activate the neuroendocrine axis in the brain, and that severing the aorta interferes with this transport. These cells have previously been shown to exhibit an increase in action potential frequency at the time of release of their hormone. In normal females, the spike frequency of the cells increased after feeding and remained high over at least the next 24 h. In females with the dorsal vessel severed, the spike frequency remained low, at levels near those of unfed females, except for a transitory increase 4 h after feeding. The spike frequency of the neurosecretory cells in females with the dorsal vessel severed increased when hemolymph from fed normal females or from those with their dorsal vessel severed was placed directly on the brains of the test females. Hemolymph taken from unfed females did not produce this response. The activity in the hemolymph was heat-stable and disappeared after pronase or trypsin digestion. Similar activity was present in the fused thoracico-abdominal ganglionic mass, but absent from fore-, mid- and hindgut and from the abdominal neurosecretory organs.

The influence of the brain hormone on retention of blood in the mid-gut of the mosquito Aedes aegypti (L.) - II. Early elimination following removal of the medial neurosecretory cells of the brain

1978 ◽  
Vol 202 (1147) ◽  
pp. 307-311 ◽  
Keyword(s):  
Aedes Aegypti ◽  
Oocyte Maturation ◽  
Blood Meal ◽  
Neurosecretory Cells ◽  
Secretory Cells ◽  
Corpus Cardiacum ◽  
Egg Development ◽  
Pars Intercerebralis ◽  
The Brain

Development of the oöcytes beyond the resting stage to maturity in mosquitoes is triggered by an egg development neurosecretory hormone from the brain. This hormone is produced by the medial neurosecretory cells of the pars intercerebralis, and in anautogenous species is stored in the corpus cardiacum until a blood-meal is taken. Removal of the head of the mosquito Aedes aegypti (L.), shortly after completion of a blood-meal, has previously been shown not only to prevent oöcyte maturation, but also to result in early elimination of the blood-meal. The work described in this paper shows that it is a factor originating in the medial neuro­-secretory cells, presumably egg development neurosecretory hormone, which is essential if the blood-meal is to be retained in the mid-gut until the oöcytes are nearing maturity.

scholarly journals Isolation of material displaying insulin-like immunological biological activity from the brain of the blowfly Calliphora vomitoria

1979 ◽  
Vol 184 (2) ◽  
pp. 221-227 ◽  
Author(s):  
H Duve ◽  
A Thorpe ◽  
N R Lazarus
Keyword(s):  
Biological Activity ◽  
Neurosecretory Cell ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Insulin Receptors ◽  
Neurosecretory Cells ◽  
Bovine Insulin ◽  
Fat Cell ◽  
Median Neurosecretory Cells ◽  
The Brain

An insulin-like material from the brain of the blowfly Calliphora vomitoria was partially purified by acid alcohol extraction, gel filtration and ion-exchange cellulose chromatography. In addition, the RF value on polyacrylamide-gel electrophoresis was determined. The material was characterized by its ability to cross-react with bovine insulin antibody and by displaying diminished immunoreactivity on dilution. It displaced specifically bound 125I-labelled insulin from rat liver plasma membrane insulin receptors and displayed insulin-like biological activity on the isolated rat fat-cell. Within 30 min of injection into Calliphora, made hypertrehalocaemic and hyperglucaemic as a result of median neurosecretory cell removal, it caused the concentrations of both sugars to return to normal. The hypothesis is put forward that the median neurosecretory cells are the source of the material.

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