Evolutionary Origin of Sensory and Neurosecretory Cell Types

Evolutionary Origin of Sensory and Neurosecretory Cell Types PDF Author: Gerhard Schlosser
Publisher: CRC Press
ISBN: 1000369137
Category : Science
Languages : en
Pages : 325

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Book Description
Most vertebrate cranial sense organs arise from placodes. These placodes give rise to sensory neurons that transmit information to the brain and neurosecretory cells. This book reviews the evolutionary origin of the sensory and neurosecretory cell types. It summarizes our current understanding of vertebrate evolution, clarifies conceptual issues relating to homology and evolutionary innovation of cell types, compares the sensory and neurosecretory cell types with similar cell types in other animals, and addresses the question of how cranial placodes evolved as novel structures in vertebrates by redeploying pre-existing and sometimes evolutionarily ancient cell types.

Evolutionary Origin of Sensory and Neurosecretory Cell Types

Evolutionary Origin of Sensory and Neurosecretory Cell Types PDF Author: Gerhard Schlosser
Publisher: CRC Press
ISBN: 1000369137
Category : Science
Languages : en
Pages : 325

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Book Description
Most vertebrate cranial sense organs arise from placodes. These placodes give rise to sensory neurons that transmit information to the brain and neurosecretory cells. This book reviews the evolutionary origin of the sensory and neurosecretory cell types. It summarizes our current understanding of vertebrate evolution, clarifies conceptual issues relating to homology and evolutionary innovation of cell types, compares the sensory and neurosecretory cell types with similar cell types in other animals, and addresses the question of how cranial placodes evolved as novel structures in vertebrates by redeploying pre-existing and sometimes evolutionarily ancient cell types.

Development of Sensory and Neurosecretory Cell Types

Development of Sensory and Neurosecretory Cell Types PDF Author: Gerhard Schlosser
Publisher: CRC Press
ISBN: 1351667831
Category : Science
Languages : en
Pages : 305

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Book Description
Most of the cranial sense organs of vertebrates arise from embryonic structures known as cranial placodes. Such placodes also give rise to sensory neurons that transmit information to the brain as well as to many neurosecretory cells. This book focuses on the development of sensory and neurosecretory cell types from cranial placodes by introducing the vertebrate head with its sense organs and neurosecretory organs and providing an overview of the various cranial placodes and their derivatives, including evidence of common embryonic primordia. Schlosser discusses how these primordia are established in the early embryo and how individual placodes develop. The latter chapters explain how various placodally derived sensory and neurosecretory cell types differentiate into discrete structures.

The Evolution of Sensory and Neurosecretory Cell Types in Bilaterian Brains

The Evolution of Sensory and Neurosecretory Cell Types in Bilaterian Brains PDF Author: Kristin Teßmar-Raible
Publisher:
ISBN:
Category :
Languages : en
Pages : 414

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Book Description


Vertebrate Cranial Placodes

Vertebrate Cranial Placodes PDF Author: GERHARD. SCHLOSSER
Publisher: CRC Press
ISBN: 9780367748531
Category :
Languages : en
Pages : 752

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Book Description
Most of the cranial sense organs of vertebrates arise from embryonic structures known as cranial placodes. Such placodes also give rise to sensory neurons that transmit information to the brain as well as to many neurosecretory cells. This book focuses on the development of sensory and neurosecretory cell types from cranial placodes by introducing the vertebrate head with its sense organs and neurosecretory organs and providing an overview of the various cranial placodes and their derivatives, including evidence of common embryonic primordia. Schlosser discusses how these primordia are established in the early embryo and how individual placodes develop. The latter chapters explain how various placodally derived sensory and neurosecretory cell types differentiate into discrete structures.

The Evolution of Sensory and Neurosecretory Cell Types in Bilaterian Brains

The Evolution of Sensory and Neurosecretory Cell Types in Bilaterian Brains PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
This thesis deals with the origin of the photosensory and neurosecretory cell types in the bilaterian brain. As the main experimental system, I used the annelid Platynereis dumerilii. Platynereis is an emerging protostomian model organism that is ideally suited for comparisons with vertebrates because it has retained many ancestral cell types, yet has a relatively simple morphology and mode of development. In the first section, I describe my contribution to the reconstruction of the urbilaterian photosensory system. By cloning and analyzing a novel opsin gene from Platynereis, I was able to provide molecular support for the hypothesis that Urbilateria (the last common ancestors of all Bilateria) already possessed two photoreceptor cell types (PRCs) 6 rhabdomeric and ciliary PRCs. I further corroborated this by the comparative analysis of different upstream regulators for each PRC type. Presumably only the rhabdomeric type was ancestrally involved in vision, while the ciliary type was a light detector in the inner brain (like the ciliary PRCs of the vertebrate pineal organ). Both types, however, were recruited into the vertebrate eye, which is thus a compound structure. This finding provides a novel basis for understanding both the molecular similarities and differences between the vertebrate and invertebrate eyes. I extended these analyses in the second section by investigating the molecular and morphological set-up of the median brain of the Platynereis larva and in particular of the apical organ (APO). The APO is a specialized, highly neurosecretory structure. From a detailed analysis of molecular markers and cellular morphologies I concluded that the median brain of trochophora type larvae with the APO as its core structure and the ventral/ median prosencephalon of vertebrates with the hypothalamus as its center share common heritage from their urbilaterian ancestor. Both vertebrate eyes and hypothalamus have been shown to require proper Hedgehog (Hh) signalling.

The Evolutionary Origins of Neural Crest and Placodes

The Evolutionary Origins of Neural Crest and Placodes PDF Author: Philip Barron Abitua
Publisher:
ISBN:
Category :
Languages : en
Pages : 111

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Book Description
The sudden appearance of neural crest and neurogenic placodes in early branching vertebrates has puzzled biologists for over a century. These embryonic tissues contribute to the development of the cranium and associated sensory organs, which were crucial for the evolution of the vertebrate head. The evolution of neural crest and neurogenic placodes has been postulated as a key event leading to the appearance of new cell types that fostered the transition from filter feeding to active predation in ancestral vertebrates. However, the evolutionary origin of neural crest and neurogenic placodes has remained obscure due to the lack of embryonic data from tunicates, the closest living relative to the vertebrates. We provide evidence that the tunicate Ciona intestinalis possesses a cephalic melanocyte lineage (a9.49) similar to neural crest that can be reprogrammed into migrating ectomesenchyme by the targeted misexpression of Twist. Our results suggest that the neural crest melanocyte regulatory network predated the divergence of tunicates and vertebrates. We propose that the co-option of mesenchyme determinants, such as Twist, into the neural plate ectoderm was crucial for the emergence of the vertebrate "new head". Furthermore, we show that Ciona intestinalis possesses a preplacodal ectoderm (PPE) that is specified by a BMP antagonist and expresses the key regulatory determinant Six1/2, a developmental program conserved across vertebrates. The Ciona PPE is shown to produce ciliated neurons that express gonadotropin-releasing hormone (GnRH), a G protein-coupled receptor for relaxin-3 (RXFP3), and a functional cyclic nucleotide gated channel (CNGA), suggestive of dual chemosensory and neurosecretory activities. These observations provide the first evidence that Ciona possesses a neurogenic placode, which produces multifunctional sensory and neurosecretory cells related to those derived from olfactory placodes of vertebrates. In vertebrates, GnRH neuroblasts are first formed in the olfactory placode and use the axon tracts of chemosensory neurons to guide them to their final destination in the hypothalamus. Tracing experiments have shown that olfactory and GnRH neurons form a direct neuronal circuit. We speculate that the PPE-derived neurons in Ciona resemble an ancestral cell type, a progenitor to the complex neuronal circuit that integrates sensory information and neuroendocrine control in vertebrates.

Behavioral Genetics of the Fly (Drosophila Melanogaster)

Behavioral Genetics of the Fly (Drosophila Melanogaster) PDF Author: Josh Dubnau
Publisher: Cambridge University Press
ISBN: 1107009030
Category : Medical
Languages : en
Pages : 309

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Book Description
A comprehensive portrayal of the behaviour genetics of the fruit fly (Drosophila melanogaster) and the methods used in these studies.

Evolution of Neurosensory Cells and Systems

Evolution of Neurosensory Cells and Systems PDF Author: Bernd Fritzsch
Publisher: CRC Press
ISBN: 1000514463
Category : Science
Languages : en
Pages : 338

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Book Description
This book is an overview of primary sensory maps of vertebrates, characterized by continuous and discrete properties. The eight primary sensory maps of vertebrates have unique features and use distinct molecular cues, cell cycle exit, and activity combinations during development, regeneration, and plasticity. As an introduction and overview, the book provides a short overview for all eight sensory senses and presents through evolution and gene regulatory networks, the molecular cues needed for sensory processing. Independent contributions are included for olfactory, vision, trigeminal, taste, vestibular, auditory, lateral line, and electroreception.

The Nervous Systems of Invertebrates: An Evolutionary and Comparative Approach

The Nervous Systems of Invertebrates: An Evolutionary and Comparative Approach PDF Author: O. Breidbach
Publisher: Birkhäuser
ISBN: 3034892195
Category : Science
Languages : en
Pages : 453

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Book Description
In this volume outstanding specialists review the state of the art in nervous system research for all main invertebrate groups. They provide a comprehensive up-to-date analysis important for everyone working on neuronal aspects of single groups, as well as taking into account the phylogenesis of invertebrates. The articles report on recently gained knowledge about diversification in the invertebrate nervous systems, and demonstrate the analytical power of a comparative approach. Novel techniques in molecular and developmental biology are creating new perspectives that point toward a theoretical foundation for a modern organismic biology. The comparative approach, as documented here, will engage the interest of anyone challenged by the problem of structural diversification in biology.

Pituitary Adenylate Cyclase-Activating Polypeptide

Pituitary Adenylate Cyclase-Activating Polypeptide PDF Author: Hubert Vaudry
Publisher: Springer Science & Business Media
ISBN: 9781402073069
Category : Medical
Languages : en
Pages : 432

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Book Description
Pituitary Adenylate Cyclase-Activating Polypeptide is the first volume to be written on the neuropeptide PACAP. It covers all domains of PACAP from molecular and cellular aspects to physiological activities and promises for new therapeutic strategies. Pituitary Adenylate Cyclase-Activating Polypeptide is the twentieth volume published in the Endocrine Updates book series under the Series Editorship of Shlomo Melmed, MD.