The cephalic neural crest exerts a critical effect on forebrain and midbrain development

Area of Science:

• Developmental Biology
• Evolutionary Biology
• Neuroscience

Background:

• Encephalisation marks a key evolutionary step from protochordates to vertebrates.
• The emergence of the transient and pluripotent neural crest (NC) coincides with vertebrate evolution.
• Cephalic NC provides skeletal protection and vascularization to rostral cephalic vesicles.

Purpose of the Study:

• To investigate the role of the neural crest (NC) in forebrain and midbrain development.
• To understand the contribution of NC cells to craniofacial and brain formation.
• To elucidate the molecular mechanisms by which NC influences brain patterning.

Main Methods:

• Surgical extirpation of cephalic NC in vertebrate models.
• Analysis of gene expression patterns (Fgf8, Shh) in developing brain structures.
• Examination of craniofacial skeleton development and neural tube closure.

Main Results:

• NC cells (NCC) regulate Fgf8 expression in the anterior neural ridge, a prosencephalic organizer.
• Cephalic NCC are essential for neural tube closure and craniofacial skeleton formation.
• NCC influence gene patterning in the prosencephalic and mesencephalic alar plates and pallial/subpallial structures.
• NC-dependent FGF8 production restricts Shh expression to the ventral prosencephalon.

Conclusions:

• The cephalic neural crest is indispensable for craniofacial structure formation.
• Neural crest cells play a critical role in the development and patterning of the preotic brain.
• NC-dependent signaling pathways are fundamental to early vertebrate brain evolution.