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.

During evolution the vertebrate head has acquired a number of unique features including specialized paired sense organs and cranial sensory ganglia. These evolutionary novelties arise from discrete thickenings of the head ectoderm known as cranial placodes. They include the adenohypophyseal, olfactory, lens, trigeminal, profundal, otic, epibranchial and lateral line placodes. While distinct in the derivatives and cell types they will form, all cranial placodes originate from a common preplacodal domain surrounding the anterior neural plate. Recent evidence suggests that the induction of this pre-placodal domain and its subsequent subdivision into individual placodes with specific identities is a multi-step process. Here we describe the development of these placodes and their derivatives and summarize recent advances in the characterization of the repertoire of transcription factors underlying their development. We also review recent studies that have started to address the role of several classes of signaling molecules in placode induction and segregation, including Bone Morphogenetic Proteins, Fibroblast Growth Factors and Wnt molecules. Table of Contents: Introduction / Cranial Placodes and Their Derivatives / Molecular Identity of Cranial Placodes / Induction and Segregation of the Cranial Placodes / Conclusion / Acknowledgments / References / Author Biographies

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.

Most of the cranial sense organs of vertebrates arise from embryonic structures known as cranial placodes. Schlosser discusses how these primordia are established in the early embryo, how individual placodes develop, and how various placodally derived sensory and neurosecretory cell types differentiate into discrete structures.

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.

World-class palaeontologists and biologists summarise the state-of-the-art on fish evolution and development.