Different actions of ecdysis-triggering hormone on the brain and ventral nerve cord of the hornworm, Manduca sexta

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.

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The Larval Eclosion Hormone Neurones in Manduca Sexta: Identification of the Brain-Proctodeal Neurosecretory System

Journal of Experimental Biology ◽

10.1242/jeb.147.1.457 ◽

1989 ◽

Vol 147 (1) ◽

pp. 457-470 ◽

Cited By ~ 4

Author(s):

JAMES W. TRUMAN ◽

PHILIP F. COPENHAVER

Keyword(s):

Central Nervous System ◽

Nervous System ◽

Manduca Sexta ◽

Nerve Cord ◽

Release Site ◽

Neurosecretory System ◽

Nerve Activity ◽

Eclosion Hormone ◽

The Central Nervous System ◽

The Brain

Larval and pupal ecdyses of the moth Manduca sexta are triggered by eclosion hormone (EH) released from the ventral nervous system. The major store of EH activity in the latter resides in the proctodeal nerves that extend along the larval hindgut. At pupal ecdysis, the proctodeal nerves show a 90% depletion of stored activity, suggesting that they are the major release site for the circulating EH that causes ecdysis. Surgical experiments involving the transection of the nerve cord or removal of parts of the brain showed that the proctodeal nerve activity originates from the brain. Retrograde and anterograde cobalt fills and immunocytochemistry using antibodies against EH revealed two pairs of neurons that reside in the ventromedial region of the brain and whose axons travel ipsilaterally along the length of the central nervous system (CNS) and project into the proctodeal nerve, where they show varicose release sites. These neurons constitute a novel neuroendocrine pathway in insects which appears to be dedicated solely to the release of EH.

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Relationships between ocellar units in the ventral nerve cord and ocellar pathways in the brain ofSchistocerca gregaria

Journal of Comparative Physiology A ◽

10.1007/bf00625447 ◽

1974 ◽

Vol 95 (3) ◽

pp. 251-262 ◽

Cited By ~ 16

Author(s):

John A. Patterson ◽

Lesley J. Goodman

Keyword(s):

Nerve Cord ◽

Ventral Nerve Cord ◽

The Brain

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Identification and Expression Analysis of Tryptophan Hydroxylase in the Brain and Ventral Nerve Cord of RagwormNeanthes japonica(Polychaeta, Annelida)

The Anatomical Record ◽

10.1002/ar.23506 ◽

2016 ◽

Vol 300 (2) ◽

pp. 415-424

Author(s):

Shun Wang ◽

Zhe Dong ◽

Shen Li ◽

Haotian Yin ◽

Zhifu Zhao ◽

...

Keyword(s):

Expression Analysis ◽

Nerve Cord ◽

Ventral Nerve Cord ◽

Tryptophan Hydroxylase ◽

The Brain

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First detection of serotonin in the nervous system of the marine calanoid copepod Centropages typicus

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315405010842h ◽

2005 ◽

Vol 85 (1) ◽

pp. 71-72 ◽

Cited By ~ 6

Author(s):

D. Benzid ◽

C. Morris ◽

R.-M. Barthélémy

Keyword(s):

Nervous System ◽

Nerve Cord ◽

Ventral Nerve Cord ◽

Calanoid Copepod ◽

Marine Species ◽

Biological Processes ◽

Calanoid Copepods ◽

The Brain ◽

Serotoninergic Nervous System ◽

Centropages Typicus

This investigation constitutes the first study of the serotoninergic nervous system in calanoid copepods (crustaceans). Serotonin (5-HT), a neurotransmitter which plays a part in many biological processes, has been detected by immunofluorescence in the brain, the circumoesophageal collar and the ventral nerve cord of the marine species Centropages typicus.

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Control of Cuticle Extensibility in the Wings of Adult Manduca At the Time of Eclosion: Effects of Eclosion Hormone and Bursicon

Journal of Experimental Biology ◽

10.1242/jeb.70.1.27 ◽

1977 ◽

Vol 70 (1) ◽

pp. 27-39

Author(s):

STUART E. REYNOLDS

Keyword(s):

Manduca Sexta ◽

Nerve Cord ◽

Gel Filtration ◽

Corpora Allata ◽

Partial Purification ◽

Active Principle ◽

Eclosion Hormone ◽

Highly Sensitive ◽

The Brain ◽

Pharate Adult

The wings of pharate adult tobacco hornworm moths, Manduca sexta, are relatively inextensible until 3 or 4 h before emergence from the pupal case. At this time the wing cuticle becomes plasticized, so that by the time of eclosion, the wings are readily extensible. This change in the mechanical properties of the wing cuticle is shown to be under the control of a factor from the head. This factor is present in the corpora cardiaca/corpora allata complex, and in the protocerebrum of the brain, being released into the blood prior to eclosion. It is able to act directly on isolated wings. The active principle was found to be indistinguishable in a number of ways from the hormone which triggers emergence from the pupal case, the eclosion hormone. Partial purification of the eclosion hormone failed to separate activity causing eclosion from activity causing wing cuticle plasticization. It is concluded that the same hormone is probably responsible for both effects. The cuticle plasticizing activity of the eclosion hormone forms the basis for a new, highly sensitive bioassay. Another factor, distinct from the eclosion hormone, is able to cause wing cuticle plasticization. This factor is found in the abdominal nerve cord, and is only released into the blood after eclosion has occurred. It is probably identical with the tanning hormone, bursicon, which is released at this time. The factor in the nerve cord which causes cuticle plasticization is indistinguishable from bursicon in a number of ways, including partial purification by gel filtration. Bursicon evidently causes a further increase in wing cuticle extensibility after eclosion, at the time of wing inflation.

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Reorganization of the ventral nerve cord in the moth Manduca sexta (L.) (Lepidoptera : Sphingidae)

International Journal of Insect Morphology and Embryology ◽

10.1016/0020-7322(94)90013-2 ◽

1994 ◽

Vol 23 (1) ◽

pp. 21-37 ◽

Cited By ~ 13

Author(s):

Therese M. Amos ◽

Karen A. Mesce

Keyword(s):

Manduca Sexta ◽

Nerve Cord ◽

Ventral Nerve Cord

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Whole-central nervous system functional imaging in larval Drosophila

Nature Communications ◽

10.1038/ncomms8924 ◽

2015 ◽

Vol 6 (1) ◽

Cited By ~ 108

Author(s):

William C. Lemon ◽

Stefan R. Pulver ◽

Burkhard Höckendorf ◽

Katie McDole ◽

Kristin Branson ◽

...

Keyword(s):

Central Nervous System ◽

Nervous System ◽

Nerve Cord ◽

Ventral Nerve Cord ◽

Activity Patterns ◽

Network Activity ◽

Imaging Data ◽

Spatiotemporal Resolution ◽

Functional Connections ◽

The Brain

Abstract Understanding how the brain works in tight concert with the rest of the central nervous system (CNS) hinges upon knowledge of coordinated activity patterns across the whole CNS. We present a method for measuring activity in an entire, non-transparent CNS with high spatiotemporal resolution. We combine a light-sheet microscope capable of simultaneous multi-view imaging at volumetric speeds 25-fold faster than the state-of-the-art, a whole-CNS imaging assay for the isolated Drosophila larval CNS and a computational framework for analysing multi-view, whole-CNS calcium imaging data. We image both brain and ventral nerve cord, covering the entire CNS at 2 or 5 Hz with two- or one-photon excitation, respectively. By mapping network activity during fictive behaviours and quantitatively comparing high-resolution whole-CNS activity maps across individuals, we predict functional connections between CNS regions and reveal neurons in the brain that identify type and temporal state of motor programs executed in the ventral nerve cord.

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A single-cell transcriptomic atlas of the adult Drosophila ventral nerve cord

eLife ◽

10.7554/elife.54074 ◽

2020 ◽

Vol 9 ◽

Cited By ~ 13

Author(s):

Aaron M Allen ◽

Megan C Neville ◽

Sebastian Birtles ◽

Vincent Croset ◽

Christoph Daniel Treiber ◽

...

Keyword(s):

Single Cell ◽

Nerve Cord ◽

Ventral Nerve Cord ◽

Sensory Information ◽

Neuronal Cell ◽

Cell Types ◽

Distinct Cell ◽

Old Adult ◽

And Behavior ◽

The Brain

The Drosophila ventral nerve cord (VNC) receives and processes descending signals from the brain to produce a variety of coordinated locomotor outputs. It also integrates sensory information from the periphery and sends ascending signals to the brain. We used single-cell transcriptomics to generate an unbiased classification of cellular diversity in the VNC of five-day old adult flies. We produced an atlas of 26,000 high-quality cells, representing more than 100 transcriptionally distinct cell types. The predominant gene signatures defining neuronal cell types reflect shared developmental histories based on the neuroblast from which cells were derived, as well as their birth order. The relative position of cells along the anterior-posterior axis could also be assigned using adult Hox gene expression. This single-cell transcriptional atlas of the adult fly VNC will be a valuable resource for future studies of neurodevelopment and behavior.

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