Principles of Current Vertebrate Neuromorphology

Area of Science:

• Neuroscience
• Developmental Biology
• Evolutionary Biology

Background:

• The vertebrate central nervous system (CNS) exhibits complex organization based on molecular patterning.
• Neural development involves transverse (neuromeres) and longitudinal patterning, creating progenitor domains.

Purpose of the Study:

• To define and delineate "fundamental morphological units" (FMUs) in the embryonic brain.
• To establish FMUs as the basic organizational units of the vertebrate brain Bauplan.
• To provide a framework for identifying and interpreting neural structures (grisea) based on FMUs.

Main Methods:

• Analysis of molecular patterning during neural plate and early neural tube stages.
• Identification of boundaries defined by neuromeres, longitudinal zones, and radial units.
• Examination of neural histogenetic processes within FMUs.

Main Results:

• The intersection of longitudinal and transverse patterning forms a checkerboard of FMUs.
• FMUs represent a topologically invariant pattern, defining the taxon-specific brain Bauplan.
• Neural development processes like proliferation, migration, and differentiation occur within FMUs.

Conclusions:

• FMUs are essential for understanding the conserved, non-Cartesian organization of the vertebrate CNS.
• Recognition of FMUs is critical for accurate identification and interpretation of grisea.
• The study provides procedures and homology criteria for FMU analysis.