Neurogenic placodes

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Neurogenic placodes
Latin placodae neurogenicae
Precursor ectoderm
Gives rise to cranial ganglia, peripheral nervous system
Code TE E05.15.2.0.0.0.1

A neurogenic placode is an area of thickening of the epithelium in the embryonic head ectoderm layer that gives rise to neurons and other structures of the sensory nervous system.[1]

Placodes are embryonic structures that give rise to structures such as hair follicles, feathers and teeth. The term "neurogenic placode" generally refers to cranial placodes that have neurogenic potential - i.e. those that give rise to neurons associated with the special senses and cranial ganglia. Cranial placodes include a diverse range of structures found across chordates, but the neurogenic placodes found in vertebrates arose later in evolution.[1]

Cranial placodes found in humans[edit]

The cranial placodes that have neurogenic potential (i.e. give rise to neurons) can be divided into two groups, the dorsolateral placodes and the epibranchial placodes.[1]

Cranial placodes not found in humans[edit]

Other ectodermal placodes[edit]

The term placode or ectodermal placode is sometimes used to refer specifically to cranial or neurogenic placodes, but is also used for areas of the ectoderm that give rise to structures such as mammary glands, feathers and hair.

References[edit]

  1. ^ a b c d Park, Saint-Jeannet (2010). Induction and Segregation of the Vertebrate Cranial Placodes.. Morgan & Claypool Life Sciences. 
  2. ^ hednk-027 — Embryo Images at University of North Carolina