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Spinal Accessory Motor Neurons in the Mouse: A Special Type of Branchial Motor Neuron?
Charles Watson1,2, Petr Tvrdik3
1School of Animal Biology, University of Western Australia, Perth, Australia.
Anatomical Record (Hoboken, N.J. : 2007)
|April 17, 2018
Summary
The spinal accessory nerve
Area of Science:
- Neuroscience
- Developmental Biology
- Comparative Anatomy
Background:
- The spinal accessory nerve's unique anatomical course has led to debate regarding its classification.
- Its pathway suggests a potential origin from the branchial motor system rather than typical spinal motor pathways.
Purpose of the Study:
- To investigate the developmental origin and classification of spinal accessory motor neurons.
- To determine if these neurons share characteristics with branchial motor neurons.
Main Methods:
- Cell lineage tracing in mice to track the development of spinal accessory motor neurons.
- Analysis of Phox2b transcription factor expression during development.
- Comparative analysis with evolutionary data from anamniote vertebrates.
Main Results:
- Spinal accessory motor neurons in mice transiently express Phox2b, a key marker for branchial motor neuron development.
- Evolutionary history suggests these neurons possess both branchial and somatic characteristics.
Conclusions:
- The expression of Phox2b provides evidence for classifying spinal accessory motor neurons as branchial motor.
- However, their evolutionary trajectory indicates they represent an atypical group with dual characteristics.
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