Neural Crest Cell Overview

Neural Crest Cells

Cells derived from ectoderm, giving rise to diverse tissues

4th Primary Germ Layer

Neural crest cells considered due to tissue diversity

Melanocytes

Pigment cells of the skin derived from neural crest cells

Schwann Cells

Peripheral nervous system support cells from neural crest cells

Chromaffin Cells

Endocrine cells of adrenal medulla from neural crest cells

Migratory Routes

Paths neural crest cells take during development

Dorsolateral Migration

Migration dorsal to somites, giving rise to melanocytes

Ventrolateral Migration

Migration ventrally through somite sclerotome

Ventral Migration

Migration ventrally through somite dermamyotome

Epithelial to Mesenchymal Transformation

Change from epithelial to mesenchymal cells for migration

Wnt and BMP Signals

Differential timing specifies ectoderm cell types

Loss of Cell Adhesion

Process involving digestion of basement membrane and cadherin loss

Cellular Motility

Involves RhoA/B for actin polymerization and Rac1 for lamelipodia growth

Attractive Signals

ECM proteins attracting migrating neural crest cells

Repulsive Signals

ECM proteins repelling migrating neural crest cells

α4β1 Integrin

Binds to ECM proteins aiding neural crest cell migration

Neural Cell Adhesion Molecules

N-CAM, N-cadherin, E-cadherin involved in cell migration

Fibronectin

Protein found in tissue surrounding migrating neural crest cells

Laminin

Protein found in tissue surrounding migrating neural crest cells

N-CAM

Expression increases in neural crest cells when migration ceases

Repulsive Forces

Regulate migration of neural crest cells; ephrin in ECM

Dorsal Root Ganglia

Formed by neural cells migrating through somites

Multi/Pluri-potency Hypothesis

Premigratory neural crest cells can form multiple derivatives

Cholinergic Neurons

Produced by vagal neural crest cells for parasympathetic system

Adrenergic Neurons

Produced by trunk neural crest cells for sympathetic system

Brainbow Lineage Tracing System

Used to track individual clones of neural crest cells

BMPs

Produced by neural plate tissue, involved in neural crest cell specification

Wnts

Produced by epidermal/mesodermal tissue, involved in neural crest cell specification

Msx1

Upregulated by Wnts and BMPs, activating proteins for cell differentiation

Foxd3

Important for cell surface protein expression in neural crest cells

Snail2

Promotes epithelial to mesenchymal transformation in neural crest cells

Sox9

Critical for chondrocyte cell fate in neural crest cells

Sox10

Critical for delamination and melanocyte or neuronal cell fates

Ephrin

Repulsive force for neural crest cells in posterior somite

Neural Crest Cell Fate

Changes as cells migrate, influenced by encountered signals

Vagal Neural Crest Cells

Give rise to parasympathetic ganglia/neurons of gut and derivatives

Trunk Neural Crest Cells

Give rise to various structures including dorsal root ganglia and sympathetic ganglia

Cardiac Neural Crest Cells

Produce melanocytes, neurons, CT, smooth muscle, blood vessels

Clonal Studies

Indicate multipotency of most premigratory and migratory neural crest cells

Brainbow Lineage Tracing Study

Revealed multipotency of individual neural crest cells and their progeny

Neural Crest Cell Specification

Occurs at the border between epidermal and neural plate tissue

Differentiation Paths

Determine fate of neural crest cells as they migrate