Morphology and Histology of the Neuroendocrine System of Bombus fervidus Fabricius (Hymenoptera: Apidae)

1966 ◽  
Vol 98 (12) ◽  
pp. 1329-1337 ◽  
Author(s):  
C. D. Crosswhite ◽  
J. T. Medler

AbstractThe following organs were investigated histologically for evidence of neurosecretion during the adult life of Bombus fervidus queens: supra- and sub-oesophageal ganglia, frontal ganglion, ventral nerve cord, corpora cardiaca, and corpora allata. The anatomy and histology of these organs are described, along with the secretory products found in the median neurosccrerory cells. A type of neurosecretion that seems unique to Hymenoptera and that appears later in the life of the queen is discussed.

1986 ◽  
Vol 64 (12) ◽  
pp. 2669-2673 ◽  
Author(s):  
B. Duff Sloley ◽  
Roger G. H. Downer ◽  
Cedric Gillott

Tryptophan, 5-hydroxytryptamine, and dopamine were measured in the frontal ganglion, corpora cardiaca, corpora allata, nerves of the suboesophageal ganglion, nerves of the thoracic ganglia, gut, testes, and ovaries of the cockroach Periplaneta americana using high performance liquid chromatography with electrochemical detection. 5-Hydroxytryptamine was demonstrated in the frontal ganglion, corpora cardiaca, corpora allata, and nerves of the suboesophageal ganglion but not in the gut, testes, ovaries, or nerves of the thoracic ganglia. These results quantitatively confirm immunohistochemical studies of 5-hydroxytryptamine in neurohaemal and nonneuronal tissues of the cockroach. Dopamine was found in all neurohaemal and nervous tissue examined. Dopamine was also found at low levels in the rectum. Tryptophan was found in all tissues examined.


1980 ◽  
Vol 88 (1) ◽  
pp. 339-350
Author(s):  
PAUL H. TAGHERT ◽  
JAMES W. TRUMAN ◽  
STUART E. REYNOLDS

Eclosion hormone activity was found in the brain and ventral ganglia of pharate pupae of Manduca sexta. No activity was detected in the corpora cardiaca-corpora allata complex. At the time of ecdysis the store of activity dropped by 50–75% in the ventral cord whereas the hormone level in the brain remained unchanged. Also, larvae whose brains were removed at the wandering stage subsequently showed pupal ecdysis behaviour and also had essentially normal levels of hormonal activity in their blood at the start of the behaviour. It was concluded that at pupal ecdysis the hormone responsible for the initiation of the behaviour is released from the ventral nerve cord rather than from the brain. The chemical characteristics of the pharate pupal eclosion hormone were determined. The factors from the brain and ventral nerve cord were both active in a number of adult and pupal eclosion hormone bioassays. Both showed an apparent molecular weight of 8500 daltons and an isoelectric point of about 5·0, values essentially the same as that seen for the adult form of the hormone. We concluded that pupal ecdysis and adult eclosion are triggered by the same hormone but for the former it is released from the ventral nerve cord and, for the latter, from the brain. The choice of release site may depend on whether or not the release is under circadian control.


1969 ◽  
Vol 47 (6) ◽  
pp. 1187-1192
Author(s):  
C. Gillott

In Coenagrion angulatum Walk. there is a single group of neurosecretory cells, median in position, on each side of the brain. The A- and B-type cells are intermingled within each group and their axons form a single pair of nerves to the corpora cardiaca. No pattern of secretory activity is discernible in the B cells. The A cells of mature nymphs and newly emerged adults are loaded with fuchsinophilic droplets but the amount of stainable material decreases as sexual maturation proceeds. A corresponding change in the location and amount of fuchsinophilic material takes place in the corpora cardiaca. In the mature nymph and young adult there is much material distributed throughout the gland. During sexual maturation it becomes less in quantity and restricted to a position adjacent to the aorta wall. A pair of stout, strongly fuchsinophilic nerves leaves the anterior end of the corpora cardiaca and passes ventrolaterally. These bypass the corpora allata and enter the thorax. Their point of termination has not been determined in this study. The corpora allata are small, roundish-oval bodies in the mature juvenile and newly emerged adult damselfly. While retaining their general shape they increase in volume several fold as sexual maturation takes place. The ventral glands are large, lobular structures in mature nymphs. Immediately after emergence they shrink and their cells become pycnotic. Generally by the fourth day of adult life they have disappeared. The results of this study are discussed in relation to those of other authors for the Odonata.


Author(s):  
Roy J. Baerwald ◽  
Lura C. Williamson

In arthropods the perineurium surrounds the neuropile, consists of modified glial cells, and is the morphological basis for the blood-brain barrier. The perineurium is surrounded by an acellular neural lamella, sometimes containing scattered collagen-like fibrils. This perineurial-neural lamellar complex is thought to occur ubiquitously throughout the arthropods. This report describes a SEM and TEM study of the sheath surrounding the ventral nerve cord of Panulirus argus.Juvenile P. argus were collected from the Florida Keys and maintained in marine aquaria. Nerve cords were fixed for TEM in Karnovsky's fixative and saturated tannic acid in 0.1 M Na-cacodylate buffer, pH = 7.4; post-fixed in 1.0% OsO4 in the same buffer; dehydrated through a graded series of ethanols; embedded in Epon-Araldite; and examined in a Philips 200 TEM. Nerve cords were fixed for SEM in a similar manner except that tannic acid was not used.


Genetics ◽  
2001 ◽  
Vol 157 (4) ◽  
pp. 1611-1622 ◽  
Author(s):  
Go Shioi ◽  
Michinari Shoji ◽  
Masashi Nakamura ◽  
Takeshi Ishihara ◽  
Isao Katsura ◽  
...  

Abstract Using a pan-neuronal GFP marker, a morphological screen was performed to detect Caenorhabditis elegans larval lethal mutants with severely disorganized major nerve cords. We recovered and characterized 21 mutants that displayed displacement or detachment of the ventral nerve cord from the body wall (Ven: ventral cord abnormal). Six mutations defined three novel genetic loci: ven-1, ven-2, and ven-3. Fifteen mutations proved to be alleles of previously identified muscle attachment/positioning genes, mup-4, mua-1, mua-5, and mua-6. All the mutants also displayed muscle attachment/positioning defects characteristic of mua/mup mutants. The pan-neuronal GFP marker also revealed that mutants of other mua/mup loci, such as mup-1, mup-2, and mua-2, exhibited the Ven defect. The hypodermis, the excretory canal, and the gonad were morphologically abnormal in some of the mutants. The pleiotropic nature of the defects indicates that ven and mua/mup genes are required generally for the maintenance of attachment of tissues to the body wall in C. elegans.


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