The cranial placodes of vertebrates – an overview

Schlosser, Gerhard. (2021). The cranial placodes of vertebrates – An overview. In Gerhard Schlosser, Development of sensory and neurosecretory cell types: Vertebrate cranial placodes, Volume 1. Boca Raton: CRC Press.

Abstract

Chapter 2 opens a series of chapters dedicated to the mechanisms underlying the embryonic development of sensory and endocrine neurosecretory cell types and organs arising from cranial placodes. After a brief introduction to cell types, the second chapter provides an overview of the various cranial placodes and their derivatives in vertebrates. The adenohypophyseal placode develops into the anterior pituitary with six different neurosecretory cell types. The olfactory placode forms the olfactory and vomeronasal epithelia with the olfactory/vomeronasal primary sensory cells and several other cell types (e.g. cells secreting GnRH and other neuropeptides, mucus producing cells of the Bowman glands, sustentacular cells). The lens placode gives rise to the transparent lens fiber cells of the lens. The otic placode invaginates to form the inner ear with its mechanosensory hair cells and the sensory neurons transmitting information from these to the brain. These are involved in the perception of gravity and body position and in hearing. The lateral line placodes produces similar cell types on the surface of the body, which respond to water movements (and in some groups to electric stimuli) in aquatic vertebrates. Finally, the profundal, trigeminal and epibranchial placodes contribute sensory neurons to various cranial ganglia.

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CRC Press

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Attribution-NonCommercial-NoDerivatives 4.0 International

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Zoology (Book Chapters)