| Name: | primary motor neuron |
|---|---|
| Synonyms: | primary motoneuron |
| Definition: | Motor neurons that arise during the first day of development. Primary motoneurons have larger diameter cell bodies and axons than secondary motoneurons and are positioned more dorsally and medially than secondary motoneurons. Primary motoneurons are present in a single bilateral pair of clusters in each spinal segment and innervate axial muscle fibers in the corresponding pair of myotomes. Axons make a conspicuous loop around the Mauthner axon before entering the ventral root. |
| Ontology: | Anatomy Ontology [ZFA:0009244] |
| Name: | spinal cord motor neuron cell fate specification |
|---|---|
| Synonyms: | |
| Definition: | The process in which a cell becomes capable of differentiating autonomously into a motor neuron in an environment that is neutral with respect to the developmental pathway. |
| Ontology: | GO: Biological Process [GO:0021520] QuickGO AmiGO |
| Name: | decreased occurrence |
|---|---|
| Synonyms: | decreased incidence |
| Definition: | An occurrence which is relatively low. |
| Ontology: | Phenotypic Quality Ontology [PATO:0002052] |